My Seastar steering helm pump went haywire so I spent some time checking
into what to do about it. This started out very depressing for me. From
what I could find on Classic Parker and The Hull Truth it seemed like
something you have to send in to get rebuilt. The unit was not working
and I did not like the time frame to get it rebuilt. Just like most
things, I didn’t think it could be that hard and as it turned out it
wasn’t. I did have other issues but the rebuild was fairly simple.
Started off with a THT post that got a response from a guy (Mark) at
Seastar. I shot an email to Mark and asked for his help. In a couple of
posts that I had seen Mark respond to there was some disappointment from
the help that he actually gave. I don’t know what actually happened in
those instances, but I can tell you that he helped me get started, sort
of. He helped me get the right rebuild kits and check valve was very concerned to
the condition of my system. The problems I had with him were that I
didn’t want to spend the entire winter working on this and I could not
get him to respond to my emails in less than 3 days. Except for the
first email I sent him that he somehow got back to me the next morning
on that one! Now in fairness to him, he may be very busy, and I could
not get a good picture of my cylinder shaft to send him. He really
seemed to want to make sure I did not have a problem with the shaft that
would just ruin the seals again as soon as I finished the job. Anyway
after that I never heard from him again.
From the originalcheckValve
.
2010年12月26日星期日
Midland Booster Check Valve
I installed power disc brakes on my 67. When I got the booster the check
valve had one of the two ports broke, so I had to replace it. If the
vacuum hose attaches to one port what attaches to the other? Is it left
open or does it get plugged? I want to make sure I get it right.
Either plug it or it will supply other vacuum related components (i.e.
a/c, tilt wheel, or speed control) But if you have a/c or tilt, you
should already have the canisters to provide the extra vacuum needed.
Since it was used on the Torinos, Cougars and possibly other Fords, it
could be for other items.
Typically, There was a steel line and hose to the check valve. If the car had a
manual trans, the extra was capped, an auto trans would have the
modulator connected to the other port.
From the originalcheckValve
.
valve had one of the two ports broke, so I had to replace it. If the
vacuum hose attaches to one port what attaches to the other? Is it left
open or does it get plugged? I want to make sure I get it right.
Either plug it or it will supply other vacuum related components (i.e.
a/c, tilt wheel, or speed control) But if you have a/c or tilt, you
should already have the canisters to provide the extra vacuum needed.
Since it was used on the Torinos, Cougars and possibly other Fords, it
could be for other items.
Typically, There was a steel line and hose to the check valve. If the car had a
manual trans, the extra was capped, an auto trans would have the
modulator connected to the other port.
From the originalcheckValve
.
Hydrogen Hog - Future Energy Concepts
Basically the water is pumped into the pressure vessel when the
internal float switch is closed. The PWM is used to produce and
electrical pulse which is tuned to the resonant frequency of the inner
electrodes. This vibrates the water trapped between the outer and inner
tubes. The outer tube is charged positive and is tuned exactly 180
degrees out of phase with the inner tube. The vibration wave is
propelled by the positive charge towards the outer tubes just to be
attenuated by the outer tube tuning.
The excited water molecules 2(H2O) now only require a fraction of the
amperage to be converted into (2H2 + O2). Also experimentation of
harmonic frequencies have produced interesting results, sometimes
exceeding HHO production of the tubes at resonance. The vessel has a
large inner and outer tube which is tuned 4 octaves lower than the outer
tubes and has a clearance between the tubes of only 1mm. This tube
produces the most heat and HHO. The smaller outer tubes have a 2mm
clearance and run cooler and take less amperage and are mounted around
the large tube assembly. The epoxy used to seal the bottom inside of the
vessel and bottom of the electrical enclosure is laced with ferrous
oxide dust 10% by weight which creates an check valve capacitor which smoothes out
the square wave pattern to a sine wave pattern which helps the
transition between off and on for the PWM. Experimentation with an air
coil after the mosfet drivers and before the load also resulted in an
increase of efficiency.
From the originalcheckValve
.
internal float switch is closed. The PWM is used to produce and
electrical pulse which is tuned to the resonant frequency of the inner
electrodes. This vibrates the water trapped between the outer and inner
tubes. The outer tube is charged positive and is tuned exactly 180
degrees out of phase with the inner tube. The vibration wave is
propelled by the positive charge towards the outer tubes just to be
attenuated by the outer tube tuning.
The excited water molecules 2(H2O) now only require a fraction of the
amperage to be converted into (2H2 + O2). Also experimentation of
harmonic frequencies have produced interesting results, sometimes
exceeding HHO production of the tubes at resonance. The vessel has a
large inner and outer tube which is tuned 4 octaves lower than the outer
tubes and has a clearance between the tubes of only 1mm. This tube
produces the most heat and HHO. The smaller outer tubes have a 2mm
clearance and run cooler and take less amperage and are mounted around
the large tube assembly. The epoxy used to seal the bottom inside of the
vessel and bottom of the electrical enclosure is laced with ferrous
oxide dust 10% by weight which creates an check valve capacitor which smoothes out
the square wave pattern to a sine wave pattern which helps the
transition between off and on for the PWM. Experimentation with an air
coil after the mosfet drivers and before the load also resulted in an
increase of efficiency.
From the originalcheckValve
.
Swing Check Valve Manufacturer
Creating malleable iron was begun in the United States in 1826 when Seth
Boyden started a foundry for the production of harness hardware and
other small castings.
Castability, heat treating and post-casting operations
Like other similar irons with the carbon formed into spherical or
nodular shapes, malleable iron exhibits good ductility. Incorrectly
considered by some to be an "old" or "dead" material, malleable iron
still has a legitimate place in the design engineer's toolbox. Malleable
is a good choice for small castings or castings with thin cross
sections (less than 0.25 inch).Other
nodular irons produced with graphite in the spherical shape can be
difficult to produce in these applications due to the formation of
carbides from the check valve rapid cooling.Malleable iron also exhibits good
fracture toughness properties in low temperature environments better
than other nodular irons due to its lower silicon content. The ductile
to brittle transformation temperature is lower than many other ductile
iron alloys.
From the originalcheckValve
.
Boyden started a foundry for the production of harness hardware and
other small castings.
Castability, heat treating and post-casting operations
Like other similar irons with the carbon formed into spherical or
nodular shapes, malleable iron exhibits good ductility. Incorrectly
considered by some to be an "old" or "dead" material, malleable iron
still has a legitimate place in the design engineer's toolbox. Malleable
is a good choice for small castings or castings with thin cross
sections (less than 0.25 inch).Other
nodular irons produced with graphite in the spherical shape can be
difficult to produce in these applications due to the formation of
carbides from the check valve rapid cooling.Malleable iron also exhibits good
fracture toughness properties in low temperature environments better
than other nodular irons due to its lower silicon content. The ductile
to brittle transformation temperature is lower than many other ductile
iron alloys.
From the originalcheckValve
.
Pressure Sealing Swing Check Valve
A good check valve is expected to be made elaborately to meet the
requirements properly. Actually, design and manufacture in conformation
with various industrial standards, there are a lot of check valves which
have been carried out with high in performance and low in maintenance.
Pressure sealing swing check valves are ones among the varieties.
Generally speaking, the pressure sealing check valve is
manufactured according to several necessary standards. And the wide
employment of the pressure sealing check valves results from the special
designs and outstanding features.
The back up ring is able to absorb thrust applied by internal pressure.
The thrust ring is able to protect the soft metallic gasket from
destination. And the gasket is the unique angular design so as to
provide superior sealing.
Besides, the inside hinge pin mounted design would provide no leakage
path to atmosphere, as well as the self aligning free floating and
non-rotating disc. And the pressure sealing swing check valve is able to
open at low differential pressures
In all, all the features lead the pressure sealing swing check valves to
be widely applied in the power stations, general industry, process
engineering for water, steam, gas, oil and other non-aggressive media.
And the further applications are undergoing.
From the originalcheckValve
.
requirements properly. Actually, design and manufacture in conformation
with various industrial standards, there are a lot of check valves which
have been carried out with high in performance and low in maintenance.
Pressure sealing swing check valves are ones among the varieties.
Generally speaking, the pressure sealing check valve is
manufactured according to several necessary standards. And the wide
employment of the pressure sealing check valves results from the special
designs and outstanding features.
The back up ring is able to absorb thrust applied by internal pressure.
The thrust ring is able to protect the soft metallic gasket from
destination. And the gasket is the unique angular design so as to
provide superior sealing.
Besides, the inside hinge pin mounted design would provide no leakage
path to atmosphere, as well as the self aligning free floating and
non-rotating disc. And the pressure sealing swing check valve is able to
open at low differential pressures
In all, all the features lead the pressure sealing swing check valves to
be widely applied in the power stations, general industry, process
engineering for water, steam, gas, oil and other non-aggressive media.
And the further applications are undergoing.
From the originalcheckValve
.
Fuel Supply line Check Valve
I'd like to replace my check valve on the Fuel Supply line in my 9-5.
The arrow in the photo points to the union between the fuel line and the
(white) check valve. the plastic fuel line is really hard stuff, I
considered using a heat gun or maybe a hose removal tool. Has anyone
out there been successful in separating the check valve from the fuel
line without having to cut the line? I would rather not cut the line if
I don't have to. I'm wondering if there's a tool out there that will
assist with this process?
I should mention that the point of the exercise is to eliminate a
problem with hard starting when cold. I've read that the check valve
"ball" can stick in the valve, allowing fuel to drain back into the tank
when the car sits overnight, which in turn means a longer cranking time
to get your fuel pressure back up in the morning. I've tried cleaning
and or replacing many other parts to solve this issue, replacing the
check valve and replacing or rebuilding the battery cables are about all
that I have left to try.
From the originalcheckValve
.
The arrow in the photo points to the union between the fuel line and the
(white) check valve. the plastic fuel line is really hard stuff, I
considered using a heat gun or maybe a hose removal tool. Has anyone
out there been successful in separating the check valve from the fuel
line without having to cut the line? I would rather not cut the line if
I don't have to. I'm wondering if there's a tool out there that will
assist with this process?
I should mention that the point of the exercise is to eliminate a
problem with hard starting when cold. I've read that the check valve
"ball" can stick in the valve, allowing fuel to drain back into the tank
when the car sits overnight, which in turn means a longer cranking time
to get your fuel pressure back up in the morning. I've tried cleaning
and or replacing many other parts to solve this issue, replacing the
check valve and replacing or rebuilding the battery cables are about all
that I have left to try.
From the originalcheckValve
.
Gas Tank check valve/vent
While doing so i noticed the check valve is 2 piece (is clipped together
like a electrical plug) being curious and to check if it was dirty i
opened it up. I wasnt expecting piece's to fall out. There is a small
black disc and large black disc then a O-ring. I'm pretty sure i know
how the big disc goes in as well as the o-ring but am puzzled on the
small disc check valve. Does anyone have a schematic that shows a break down, or has
any one else opened one up. I dont want to spend 20 bucks on a new one
when this one is fine. I have searched for threads and asked ?'s but
havent had much response so i thought i would start this thread. Someone
please help me out.
I will buy a new one before i leave it out for 20 bucks, but would rather just figure out how the pieces set in there.
I cant believe everyone just tosses them or buys a new one though.
Hopefully i can save a bill and get this thing back together.
From the originalcheckValve
.
like a electrical plug) being curious and to check if it was dirty i
opened it up. I wasnt expecting piece's to fall out. There is a small
black disc and large black disc then a O-ring. I'm pretty sure i know
how the big disc goes in as well as the o-ring but am puzzled on the
small disc check valve. Does anyone have a schematic that shows a break down, or has
any one else opened one up. I dont want to spend 20 bucks on a new one
when this one is fine. I have searched for threads and asked ?'s but
havent had much response so i thought i would start this thread. Someone
please help me out.
I will buy a new one before i leave it out for 20 bucks, but would rather just figure out how the pieces set in there.
I cant believe everyone just tosses them or buys a new one though.
Hopefully i can save a bill and get this thing back together.
From the originalcheckValve
.
A Sewer Check Valve Can Prevent Damage From Sewer Back-Ups
A Sewer Back Up Can Result In A Flooded Basement And Extensive
Damage. The Ansewer May Be A Sewer Check Valve. In certain areas of the
country a public sewer back up may cause a flooded basement. A public
sewer may back up due to heavy rains or over development in the area.
Other possible causes of a sewer back up could be a high groundater
table, a malfunctioning public sewer, and various other causes as well.
As in all of these cases a sewer back up does not mean that thehouse sewer
is defective or needs to be cleaned. A backwater check valve many times
can be the solution to stopping a flooded basement from happening and
stopping a public sewer back up. A sewer check valve is a one-way valve
that automatically closes and only lets water out, not in, when water
attempts to enter the house sewer system. A backwater check valve (sewer
check valve) is a very simple and dependable device.
Removing dirt or debris from the flapper inside a sewer check valve
is vital for it continue to work properly. Removing four screws with any
number of simple tools provides access to the check valve, with
maintenance only taking minutes. No special skill or tools are needed,
and this maintenance will ensure many years of dependable operation. It
is also very important that the sewer check valve be installed on the
street side of the house trap. By installing the device in this manner
it will ensure that a public sewer back up never reaches the point of
the house trap where sewerage can possibly leak out.
It is highly recommended that a licensed plumber specializing in
sewer work be used for this type of work. Most reputable plumbers will
have experience installing sewer check valves professionally and
successfully for many years and have a long list of satisfied customers.
From the originalcheckValve
.
Damage. The Ansewer May Be A Sewer Check Valve. In certain areas of the
country a public sewer back up may cause a flooded basement. A public
sewer may back up due to heavy rains or over development in the area.
Other possible causes of a sewer back up could be a high groundater
table, a malfunctioning public sewer, and various other causes as well.
As in all of these cases a sewer back up does not mean that thehouse sewer
is defective or needs to be cleaned. A backwater check valve many times
can be the solution to stopping a flooded basement from happening and
stopping a public sewer back up. A sewer check valve is a one-way valve
that automatically closes and only lets water out, not in, when water
attempts to enter the house sewer system. A backwater check valve (sewer
check valve) is a very simple and dependable device.
Removing dirt or debris from the flapper inside a sewer check valve
is vital for it continue to work properly. Removing four screws with any
number of simple tools provides access to the check valve, with
maintenance only taking minutes. No special skill or tools are needed,
and this maintenance will ensure many years of dependable operation. It
is also very important that the sewer check valve be installed on the
street side of the house trap. By installing the device in this manner
it will ensure that a public sewer back up never reaches the point of
the house trap where sewerage can possibly leak out.
It is highly recommended that a licensed plumber specializing in
sewer work be used for this type of work. Most reputable plumbers will
have experience installing sewer check valves professionally and
successfully for many years and have a long list of satisfied customers.
From the originalcheckValve
.
Nuclear power plant site selection of safety
As the use of nuclear energy expert, Howard has called for speeding up development of nuclear power.
July
16, Tokyo, Japan earthquake triggered a nuclear power plant nuclear
accident, making the safety of nuclear power has once again aroused
people’s attention. However, FOK Yiu Kwong said, do not worry about similar things will happen in China.
Ensure the safety of nuclear power plant siting
Where nuclear power plant built? This is beginning to seriously consider nuclear power planning problems.
"Nuclear power plant site selection of safety,Pneuamtic butterfly valve,
environmental protection has made a full account taken into
consideration both the environmental impact of nuclear power plants,
also consider the environmental impact of nuclear power." FOK Yiu Kwong
said.
From the originalcheckValve
.
July
16, Tokyo, Japan earthquake triggered a nuclear power plant nuclear
accident, making the safety of nuclear power has once again aroused
people’s attention. However, FOK Yiu Kwong said, do not worry about similar things will happen in China.
Ensure the safety of nuclear power plant siting
Where nuclear power plant built? This is beginning to seriously consider nuclear power planning problems.
"Nuclear power plant site selection of safety,Pneuamtic butterfly valve,
environmental protection has made a full account taken into
consideration both the environmental impact of nuclear power plants,
also consider the environmental impact of nuclear power." FOK Yiu Kwong
said.
From the originalcheckValve
.
sump check valve
Singles plated check valve is one kind of Check valves. It is a mechanical device, a valve, which normally allows a fluid to flow through it in only one direction.
Just as check valves, the single plate check valve is suitable for all
kinds of liquid pipe system. The advantages of single plate check valve
is as follow: simple in structure, beautiful appearance, light weight,
convenient in installation, etc. This valve is mainly applicable to
water supply system, chemical industry, petroleum, metallurgy, etc.
Industrial departments are installed on the site is the most suitable
space limit. Furthermore, the single plate check valve can be installed
without any special pipe support no matter in horizontal or in vertical
line.
From the originalcheckValve
.
Just as check valves, the single plate check valve is suitable for all
kinds of liquid pipe system. The advantages of single plate check valve
is as follow: simple in structure, beautiful appearance, light weight,
convenient in installation, etc. This valve is mainly applicable to
water supply system, chemical industry, petroleum, metallurgy, etc.
Industrial departments are installed on the site is the most suitable
space limit. Furthermore, the single plate check valve can be installed
without any special pipe support no matter in horizontal or in vertical
line.
From the originalcheckValve
.
2010年12月15日星期三
why would a check valve be necessary?
All 1/2" steel piping with #2 fuel oil flowing
There is an
actuated shutoff valve then about a 20' run of pipe then a 10' drop and
another 8' run to an oil gun with tip out in the furnace.
There is
a negative pressure coming from the furnace, and there is a small
additional negative pressure created during a 30 second purge with the
oil off and air still on... probably equals about 3 psi total...
So why would there need to be a check valve installed immediately before the oil gun?
Whouldnt
the pressure after the valve be 0 and the pressure from the atmosphere
be like 15-3 = 12psi + friction and such... so the oil would all stay in
the line except for maybe a little that would come out that was in
around that last 8' run?
I think a check valve would do little to
almost nothing here... a couple people are insisting that there HAS to
be a check valve there... am I missing something?
It is most likely to prevent the atomization air (compressed air)
from backing up through the burner nozzle. Fuel oil and compressed air
connections will be near the windbox, and these go to the oil gun which
uses the pressurized air to atomize the oil.
I am not familiar
with the specifics of how oil burner guns are configured, but it seems
possible that the air could backup through the oil line if the oil pump
was suddenly shut off or a valve closed.
The primary purpose of the check valve may be to introduce a forward
pressure drop (cracking pressure to open the spring) and therefore
prevent the oil lines from draining into the furnace when it is
shutdown.
For one thing it will keep air that replaces the oil that has run out
the end of the pipe from making its way back to wherever it can make its
way back to.
From the originalCheck Valve
.
There is an
actuated shutoff valve then about a 20' run of pipe then a 10' drop and
another 8' run to an oil gun with tip out in the furnace.
There is
a negative pressure coming from the furnace, and there is a small
additional negative pressure created during a 30 second purge with the
oil off and air still on... probably equals about 3 psi total...
So why would there need to be a check valve installed immediately before the oil gun?
Whouldnt
the pressure after the valve be 0 and the pressure from the atmosphere
be like 15-3 = 12psi + friction and such... so the oil would all stay in
the line except for maybe a little that would come out that was in
around that last 8' run?
I think a check valve would do little to
almost nothing here... a couple people are insisting that there HAS to
be a check valve there... am I missing something?
It is most likely to prevent the atomization air (compressed air)
from backing up through the burner nozzle. Fuel oil and compressed air
connections will be near the windbox, and these go to the oil gun which
uses the pressurized air to atomize the oil.
I am not familiar
with the specifics of how oil burner guns are configured, but it seems
possible that the air could backup through the oil line if the oil pump
was suddenly shut off or a valve closed.
The primary purpose of the check valve may be to introduce a forward
pressure drop (cracking pressure to open the spring) and therefore
prevent the oil lines from draining into the furnace when it is
shutdown.
For one thing it will keep air that replaces the oil that has run out
the end of the pipe from making its way back to wherever it can make its
way back to.
From the originalCheck Valve
.
Relief Valve Discharge Piping
Anyone out there can help me with this. In ASME B31.1 Appendix II there is a method for Relief Valve Discharge Piping Design. One of the equations is to determine the pressure at the vent exit P3. In certain cases P3 calculated by this equation can be less than atmospheric (14.7 Psia). From other sources I have come across, if this occurs in the pipework sizing then the exit pressure P3 must be set to atmospheric (14.7 Psia) and the process is to work backwards along the pipe to determine if the calculated pressure drop causes a problem. My problem is that ASME B31.1 does not warn the user that if the calculated value of P3 is less than atmospheric then P3 must be set to atmospheric.The example given is such that P3 is well above the atmospheric pressure hence no problem.
If I consider the other sources then by setting P3 to atmospheric, then calculate P2,V2 and check for blowback then you get a problem. On the other hand if you use the calculated value of P3 and calculate P2,V2 then blowback is not a problem. Please advise.
/////////////////////////////////////////////
This kind of problem always exist if the capacity and orifice
size are high and set pressure as well as back pressure of the safety
valve are very low. Outlet size of the safety valve becomes large with
the low back pressure. According to my experience, you can solve your
problem in two ways:
1. Reduce pressure drop of the discharge pipe by
shortening the length, eliminating miters or elbows and selecting
discharge pipe diameter as large as possible ( however this does not
work all the time due to blowback calculation ). Most of the cases we
need to provide a silencer due to noise problem. Limiting pressure drop
on the silencer might be helpfull.
2. Basicaly, this is a valve
selection problem. Increasing the back pressure ( for example from 10%
to 25% ) of the safety valve will solve the problem. Sometimes, getting
two smaller valves instead of single valve may be adequate. In both
cases, you need to consult your SV supplier.
I guess your
calculation is on a spreadsheet. If you make a couple iterations by
changing the variables ( diameter of the discharge duct,losses,the back
pressure of the safety valve, capacity, valve outlet size)you can see
the behaviour of the system. If you can see what makes your calculation
ineffective than you can eliminate your problem easily.
I hope this helps. If you need further help, let me know the details about the system and the safety valve.
From the originalCheck Valve
.
If I consider the other sources then by setting P3 to atmospheric, then calculate P2,V2 and check for blowback then you get a problem. On the other hand if you use the calculated value of P3 and calculate P2,V2 then blowback is not a problem. Please advise.
/////////////////////////////////////////////
This kind of problem always exist if the capacity and orifice
size are high and set pressure as well as back pressure of the safety
valve are very low. Outlet size of the safety valve becomes large with
the low back pressure. According to my experience, you can solve your
problem in two ways:
1. Reduce pressure drop of the discharge pipe by
shortening the length, eliminating miters or elbows and selecting
discharge pipe diameter as large as possible ( however this does not
work all the time due to blowback calculation ). Most of the cases we
need to provide a silencer due to noise problem. Limiting pressure drop
on the silencer might be helpfull.
2. Basicaly, this is a valve
selection problem. Increasing the back pressure ( for example from 10%
to 25% ) of the safety valve will solve the problem. Sometimes, getting
two smaller valves instead of single valve may be adequate. In both
cases, you need to consult your SV supplier.
I guess your
calculation is on a spreadsheet. If you make a couple iterations by
changing the variables ( diameter of the discharge duct,losses,the back
pressure of the safety valve, capacity, valve outlet size)you can see
the behaviour of the system. If you can see what makes your calculation
ineffective than you can eliminate your problem easily.
I hope this helps. If you need further help, let me know the details about the system and the safety valve.
From the originalCheck Valve
.
Adding a proportional control valve to an LP gas valve train
I'm building a 200-L fully automated, gas-fired pilot brewery. Here's the problem: I need to be able to remotely modulate the flame from a ~50,000-Btu/hr impinged jet gas burner via a potentiometer mounted on the control panel. The only valves I've been able to find that meet my criteria are the Asco 8202/3 Proportional solenoid valves, but they don't appear to be compataible with combustable gas; and the Asco AH8D series actuators/V710 body, which seem to be too big.
Basically, I need to be able to throttle down the burner as the temperature in the kettle approaches 100*C, because of the instability of the wort as it comes to a boil. (Wort is what beer is called prior to fermentation).
Wort coming to an initial boil has a nasty tendency to violently boil over the top of the kettle if the firing rate is too high at boiling point, until the proteins in the wort have had time to coagulate, and then it settles down for the remainder of the 1-hr boil.
Does anyone have any ideas on how to safely and reliably perform this task, or better yet, a good book? Ultimately, I have to thoroughly understand this system because I am the one who is going to have to build and maintain it.
Check Belimo for an actuator. they have some small ones... you may have to make a small bracket to hold the actuator from rotating and you can use a coupler/set screw to extend the shaft of the butterball valve if needed. Powerflame uses this setup on their X4 modulating burner, but with a honeywell actuator. The belimo is smaller though. I will look tomorrow and let you know which one I used before.
You can put this valve after everything in the gas train.
At 50MBH, I would use the 1/2" valve. You aren't going to have "great" control, but the Belimo actuators have "stops" you can use to limit the stroke. That shouldn't be an issue. You probably end up around 50-70% of full rate??? Is that your target?
Hopefully you have access to a combustion analyzer so you can check the CO.
Also, I don't have a problem helping you. If you are making beer... that is a good thing.
I assume you are just putting this burner under the boiling pot,
right? If this is the case, it would be difficult to get a proper CO
measurement. Definitely have some sort of CO alarm in the area
though. Most of them will sound off at 200ppm or so. That standard
changed within the last few years and I don't remember the exact point
at which they sound off.
Will you be using natural gas or
LP? Regardless, the burner appears to operate at 3.5"WC on Natural and
11" on LP. These manifold pressure will yeild full input of the
burner. Will you have a gas flow meter in line that you can clock?
Turndown ratios are listed on the Solarflo website. Don't exceed those and you should be ok. Rate can be calculated based on manifold pressure. for example...
SQRT(p2/p1)* q1 = q2
Say
you reduced the manifold pressure with your valve by half, so... the
square root of .5 is .707, so .707 times 50MBH gets you down to
35.36MBH. Make sense? Maybe you already know how to do this, so no
offence if I am stating the obvious to you. This is a basic calculation
and will work for what you are doing.
From the originalCheck Valve
.
Basically, I need to be able to throttle down the burner as the temperature in the kettle approaches 100*C, because of the instability of the wort as it comes to a boil. (Wort is what beer is called prior to fermentation).
Wort coming to an initial boil has a nasty tendency to violently boil over the top of the kettle if the firing rate is too high at boiling point, until the proteins in the wort have had time to coagulate, and then it settles down for the remainder of the 1-hr boil.
Does anyone have any ideas on how to safely and reliably perform this task, or better yet, a good book? Ultimately, I have to thoroughly understand this system because I am the one who is going to have to build and maintain it.
Check Belimo for an actuator. they have some small ones... you may have to make a small bracket to hold the actuator from rotating and you can use a coupler/set screw to extend the shaft of the butterball valve if needed. Powerflame uses this setup on their X4 modulating burner, but with a honeywell actuator. The belimo is smaller though. I will look tomorrow and let you know which one I used before.
You can put this valve after everything in the gas train.
At 50MBH, I would use the 1/2" valve. You aren't going to have "great" control, but the Belimo actuators have "stops" you can use to limit the stroke. That shouldn't be an issue. You probably end up around 50-70% of full rate??? Is that your target?
Hopefully you have access to a combustion analyzer so you can check the CO.
Also, I don't have a problem helping you. If you are making beer... that is a good thing.
I assume you are just putting this burner under the boiling pot,
right? If this is the case, it would be difficult to get a proper CO
measurement. Definitely have some sort of CO alarm in the area
though. Most of them will sound off at 200ppm or so. That standard
changed within the last few years and I don't remember the exact point
at which they sound off.
Will you be using natural gas or
LP? Regardless, the burner appears to operate at 3.5"WC on Natural and
11" on LP. These manifold pressure will yeild full input of the
burner. Will you have a gas flow meter in line that you can clock?
Turndown ratios are listed on the Solarflo website. Don't exceed those and you should be ok. Rate can be calculated based on manifold pressure. for example...
SQRT(p2/p1)* q1 = q2
Say
you reduced the manifold pressure with your valve by half, so... the
square root of .5 is .707, so .707 times 50MBH gets you down to
35.36MBH. Make sense? Maybe you already know how to do this, so no
offence if I am stating the obvious to you. This is a basic calculation
and will work for what you are doing.
From the originalCheck Valve
.
Running different pumps in series
I am proposing a system using existing pumps and lines to transport
water to an area that now requires this water in our factory.
For
simplicity sake, this proposal utilises two centrif pumps in series,
20HP and 10HP although the first pump (20HP) would be sufficient for the
task.
The system will be run manually. If the second pump is not
running when the system is started, is there a possibility the second
pump may start spinning in reverse as the water flows through it from
the first pump? What then if the operator starts the second pump? Is
there anything else to be wary about with a system like this?
Bypass the 10Hp pump with valves. If the 20 HP
is running and spinning the 10 Hp pump backwards all manner of bad
things can happen, the impeller comes loose, the 10 Hp motor starts and
tears up the 10 Hp pump.
If the 20 Hp can do the job isolated the
10 Hp pump until needed. You overcome all types problems, hydraulic,
mechanical, doing this.
Much as I hate to say this you might just use
a check valve in the discharge of the 10 Hp. But valves will be better
as it allows you to isolated a pump for maintenance.
1. If the pumps are connected in series and are similar you probably do not risk a reverse rotation.
2. If the pumps are connected in parallel it is usuall to install check valves to avoid reverse rotation
3. If you want to operate both: check that the pumps flow are compatibles and that the suction pressure of the second pump is in the operational range.
4. If you operate the 20 hp pump and the 10 hp pump is off and (no by-pass) you may:
a)have higher presure drop on the line, the pump will be like an obstruction.
b) there is the risk of induction in the motor by the residual magnetism. this could damage the motor windings.
you could add a check as by pass for the second pump and this may work without any electronics or opening valves.
From the originalCheck Valve
.
water to an area that now requires this water in our factory.
For
simplicity sake, this proposal utilises two centrif pumps in series,
20HP and 10HP although the first pump (20HP) would be sufficient for the
task.
The system will be run manually. If the second pump is not
running when the system is started, is there a possibility the second
pump may start spinning in reverse as the water flows through it from
the first pump? What then if the operator starts the second pump? Is
there anything else to be wary about with a system like this?
Bypass the 10Hp pump with valves. If the 20 HP
is running and spinning the 10 Hp pump backwards all manner of bad
things can happen, the impeller comes loose, the 10 Hp motor starts and
tears up the 10 Hp pump.
If the 20 Hp can do the job isolated the
10 Hp pump until needed. You overcome all types problems, hydraulic,
mechanical, doing this.
Much as I hate to say this you might just use
a check valve in the discharge of the 10 Hp. But valves will be better
as it allows you to isolated a pump for maintenance.
1. If the pumps are connected in series and are similar you probably do not risk a reverse rotation.
2. If the pumps are connected in parallel it is usuall to install check valves to avoid reverse rotation
3. If you want to operate both: check that the pumps flow are compatibles and that the suction pressure of the second pump is in the operational range.
4. If you operate the 20 hp pump and the 10 hp pump is off and (no by-pass) you may:
a)have higher presure drop on the line, the pump will be like an obstruction.
b) there is the risk of induction in the motor by the residual magnetism. this could damage the motor windings.
you could add a check as by pass for the second pump and this may work without any electronics or opening valves.
From the originalCheck Valve
.
Air entraped so
We have an slow closing valve in the end of a vertical pump column which does not function correctly. The float is being kneaded. We are thinking to install an orifice plate in the flange of the base of the valve to reduce water hammer.This will help to solve the problem? Or it has another solution?
When the vertical pump starts, the air inside the column (above the
water level) will be forced by the water pumped to escape by the slow
closing valve- there is a check valve, just after the valve, retaining
downstream water. The water velocity in the column depends on the
velocity of air exit. We are intending to reduce the velocity of air
escape with an orificie before the valve (with a minor diameter than
valve). Thus the water will arrive at the float with lesser velocity
and minor impact. (When the impact occurs the float is launched against
the valve body being damaged.
If your "slow closing" valve is a float controlled air vent, then an upstream orifice plate will work just fine on pressure rise. You also need to consider what will happen when the pump turns off. It may be necessary to let extra air in via a check valve, or something fancier, when the pump stops.
In fact you may want to review the entire system hydraulics as the existing valve may not be necessary if the air can be carried away with the water.
It may be worth considering that if the float is being deformed (kneaded?), then you have some fairly serious pressure spikes to deal with.
The normal ways of dealing with them are:
1) keep some air in the system to cushion the impact. This is what your orifice plate will do.
2) Stop the pressure rising so fast. This is what a pump control valve, and, to a lesser extent, a fixed bypass will do. Alternatives are variable speed drive ramp start and soft starter. With the soft starter you will find that everyone says they are great at the beginning, and then they get evasive when you request finalised speed/time information, so be careful before committing.
And it is normally best to have the check valve close to the pump discharge; not at the top of the line. Reduces vacuum hammer problems, and will reduce the amount of air getting in as the riser will not be under suction when the pump is off.
From the originalCheck Valve
.
When the vertical pump starts, the air inside the column (above the
water level) will be forced by the water pumped to escape by the slow
closing valve- there is a check valve, just after the valve, retaining
downstream water. The water velocity in the column depends on the
velocity of air exit. We are intending to reduce the velocity of air
escape with an orificie before the valve (with a minor diameter than
valve). Thus the water will arrive at the float with lesser velocity
and minor impact. (When the impact occurs the float is launched against
the valve body being damaged.
If your "slow closing" valve is a float controlled air vent, then an upstream orifice plate will work just fine on pressure rise. You also need to consider what will happen when the pump turns off. It may be necessary to let extra air in via a check valve, or something fancier, when the pump stops.
In fact you may want to review the entire system hydraulics as the existing valve may not be necessary if the air can be carried away with the water.
It may be worth considering that if the float is being deformed (kneaded?), then you have some fairly serious pressure spikes to deal with.
The normal ways of dealing with them are:
1) keep some air in the system to cushion the impact. This is what your orifice plate will do.
2) Stop the pressure rising so fast. This is what a pump control valve, and, to a lesser extent, a fixed bypass will do. Alternatives are variable speed drive ramp start and soft starter. With the soft starter you will find that everyone says they are great at the beginning, and then they get evasive when you request finalised speed/time information, so be careful before committing.
And it is normally best to have the check valve close to the pump discharge; not at the top of the line. Reduces vacuum hammer problems, and will reduce the amount of air getting in as the riser will not be under suction when the pump is off.
From the originalCheck Valve
.
Reverse flow in vertical shaft pumps
I've to dewater a reservoir to sea by using a wet pit mounted vertical
shaft pump (axial flow), for watering the same reservoir i want to
eliminate the extra pipe way and channel as there is positive head over
the reservoir (sea level is 2.5 meter avove the reservoir)i am planning
to use the dischrge flnge of the pump as the suction from sea to
reservoir without runing the pump, Does anybody know what will happen to
pump bearing wise?? Anyhow is it practible?? Please let me know about
any remedies or cautions!!
Thanking you in advance.
If the pump motor is over the sea level, you have the first problem solved.
Normally the pumps have a check valve on the discharge side if it is so you must take it off.
BUT
The
first to be aware is than when the water goes back the pump , the shaft
will rotate in counter wise from original and the threaded parts could
disassembly.
If you want to use the same pipe , use a check valve
upward the pump and do a tee branch where to put valve , so when the
pump is off you open this valve and can fill again your reservoir.
Dont worry about your english , mine is not better.
And you could fit a hold back on the pump drive so that it can only rotate
in the desired direction. When the flow reverses the water will go
through the pump. Be careful to check how the impeller is secured to the
shaft. Sometimes they are simply screwed on and flow reversal can drive
the impeller off the shaft and it will foul the casing.
Check with pump manufacturer.
Discharge check valves could be replaced with an actuated valve so flow could be stopped in reverse if required.
From the originalCheck Valve
.
shaft pump (axial flow), for watering the same reservoir i want to
eliminate the extra pipe way and channel as there is positive head over
the reservoir (sea level is 2.5 meter avove the reservoir)i am planning
to use the dischrge flnge of the pump as the suction from sea to
reservoir without runing the pump, Does anybody know what will happen to
pump bearing wise?? Anyhow is it practible?? Please let me know about
any remedies or cautions!!
Thanking you in advance.
If the pump motor is over the sea level, you have the first problem solved.
Normally the pumps have a check valve on the discharge side if it is so you must take it off.
BUT
The
first to be aware is than when the water goes back the pump , the shaft
will rotate in counter wise from original and the threaded parts could
disassembly.
If you want to use the same pipe , use a check valve
upward the pump and do a tee branch where to put valve , so when the
pump is off you open this valve and can fill again your reservoir.
Dont worry about your english , mine is not better.
And you could fit a hold back on the pump drive so that it can only rotate
in the desired direction. When the flow reverses the water will go
through the pump. Be careful to check how the impeller is secured to the
shaft. Sometimes they are simply screwed on and flow reversal can drive
the impeller off the shaft and it will foul the casing.
Check with pump manufacturer.
Discharge check valves could be replaced with an actuated valve so flow could be stopped in reverse if required.
From the originalCheck Valve
.
Free flooding of subsea pipeline
I have a problem to calculate a free flooding of offshore subsea pipeline. I would like to calculate it with as minimum aproximations as possible.The calculation is not so simple since the pressure in pipeline is changing as the pipeline is filled with water. The concept is to fill the pipeline from one side (deeper side)and to have a check valve at the other side.
Any equation for a start or a spreadsheet?
There could be several parameters that affect how the calculations could be done.
Contents:
What will the pipeline contain at the time it is flooded? Such as natural gas, crude oil, gas and oil?
Internal Pressures:
What will be the pipeline's internal pressure profile at the time the valve opens?
External Pressures:
What is the pipeline's external pressure profile (depths of the pipeline)?
Before it couldn't be answered generally, since if the air pressure
inside at time of opening was greater than the sea water's pressure
outside, the calculations would have to include a step for pressure
equalization from escaping air from the lowest valve, before you could
assume the remaining air would be displaced to the highest valve(ball valve).
You
didn't mention the profile. I think its possible that an undulating
pipeline profile may trap air at local high points. That air might lock
at the high points and not free flow to the exit point. Can you assume
there is a continuous constant slope from low to high?
Assuming a continuous slope, that's enough water pressure to compress
the air to roughly 11 barA, or 1/11th of the pipeline's air filled
inside volume at 1 BarA, if you opened the lower valve first without
opening the air escape valve. Infow rate would be whatever the full
open Cv is of the valve times the differential pressure across the valve
at any given time, which would tend to reduce as the pipe filled, with
an inside pressure (P2) = appx = P1 x V1 / V2, where V1 is initial
volume and V2 is the volume of air at any given time. Since pressures
arn't really too significant (compressibility factor of air = 1) I think
you could just assume some reasonable time steps and incrementally
calculate the inside volume, the inside pressure, outside pressure = 10
barG, and get the flowrate across the valve for the next timestep and
arrive at a reasonable approximation to the water filling rate through
that 4" valve. Once the pressures had equalized, you could do the same
thing (kinda' in reverse) with opening the air escape valve and
calculating the airflow rate out as the water displaced it.
From the originalCheck Valve
.
Any equation for a start or a spreadsheet?
There could be several parameters that affect how the calculations could be done.
Contents:
What will the pipeline contain at the time it is flooded? Such as natural gas, crude oil, gas and oil?
Internal Pressures:
What will be the pipeline's internal pressure profile at the time the valve opens?
External Pressures:
What is the pipeline's external pressure profile (depths of the pipeline)?
Before it couldn't be answered generally, since if the air pressure
inside at time of opening was greater than the sea water's pressure
outside, the calculations would have to include a step for pressure
equalization from escaping air from the lowest valve, before you could
assume the remaining air would be displaced to the highest valve(ball valve).
You
didn't mention the profile. I think its possible that an undulating
pipeline profile may trap air at local high points. That air might lock
at the high points and not free flow to the exit point. Can you assume
there is a continuous constant slope from low to high?
Assuming a continuous slope, that's enough water pressure to compress
the air to roughly 11 barA, or 1/11th of the pipeline's air filled
inside volume at 1 BarA, if you opened the lower valve first without
opening the air escape valve. Infow rate would be whatever the full
open Cv is of the valve times the differential pressure across the valve
at any given time, which would tend to reduce as the pipe filled, with
an inside pressure (P2) = appx = P1 x V1 / V2, where V1 is initial
volume and V2 is the volume of air at any given time. Since pressures
arn't really too significant (compressibility factor of air = 1) I think
you could just assume some reasonable time steps and incrementally
calculate the inside volume, the inside pressure, outside pressure = 10
barG, and get the flowrate across the valve for the next timestep and
arrive at a reasonable approximation to the water filling rate through
that 4" valve. Once the pressures had equalized, you could do the same
thing (kinda' in reverse) with opening the air escape valve and
calculating the airflow rate out as the water displaced it.
From the originalCheck Valve
.
2010年12月9日星期四
chiller's shoot-off valves
As is known, obligatory attributes, necessary at installation chiller,
are so-called shoot-off valves.
I am not quite sure, but I assume,that it's made for when chiller does
not work, the pump consumed smaller power (1), and that the cooled
water did not proceed through evaporator(And condenser) (2).
My question: If nevertheless to open of the valve at not working chiller,
provided that In system there is some chillers and some of them continue to
work, i.e. to cool water, what negative consequences it will result?
I assume that you are referring to shutoff valves, which are used to
stop the flow of water through a chiller which is not operating.
When
water is allowed to flow through the evaporator of a chiller which is
not operating, this water is bypassing the operating chiller, so the
temperature of your chilled water system will be affected. It should
not have any adverse consequences on the non-operating chiller itself,
but you should ensure that the operating chiller is still receiving
adequate flow.
If water is allowed to flow through the condenser
of a non-operating chiller, it should not cause problems with that
chiller as long as the temperature is within the range that the
manufacturer specifies.
Be carefull....Depending on your CHW pipe configuration you may need the isolating valves even with the check valves and dedicated pumps for each chillers. I had an instance where water was induced through the Chiller/Pump that was switched OFF by the pump that was running and it effected my chilled water supply temperature.
From the original1Check Valve.com
.
are so-called shoot-off valves.
I am not quite sure, but I assume,that it's made for when chiller does
not work, the pump consumed smaller power (1), and that the cooled
water did not proceed through evaporator(And condenser) (2).
My question: If nevertheless to open of the valve at not working chiller,
provided that In system there is some chillers and some of them continue to
work, i.e. to cool water, what negative consequences it will result?
I assume that you are referring to shutoff valves, which are used to
stop the flow of water through a chiller which is not operating.
When
water is allowed to flow through the evaporator of a chiller which is
not operating, this water is bypassing the operating chiller, so the
temperature of your chilled water system will be affected. It should
not have any adverse consequences on the non-operating chiller itself,
but you should ensure that the operating chiller is still receiving
adequate flow.
If water is allowed to flow through the condenser
of a non-operating chiller, it should not cause problems with that
chiller as long as the temperature is within the range that the
manufacturer specifies.
Be carefull....Depending on your CHW pipe configuration you may need the isolating valves even with the check valves and dedicated pumps for each chillers. I had an instance where water was induced through the Chiller/Pump that was switched OFF by the pump that was running and it effected my chilled water supply temperature.
From the original1Check Valve.com
.
pipe vibration in stainless steel pipe
I have a pipe vibration issue. Each time the submersible pumps starts the stainless steel pipe vibrates. I have two static mixers, which I can not remove. They are required because we have found that although removing the mixers has more or less eliminated vibration, it has affected the chemical mixing efficiency dramatically. Therefore I need to eliminate the vibration using other methods. I thought of bolting the pipe supports to the pipe flanges, however, I was advise that that merely transfers the vibration elsewhere along the pipe.
I was even thinking of putting in flexible couplings, but once again this may reduce vibration but not eliminate.
Does anyone know how to eliminate pipe vibration on stain less steel pipes? The current pipe support are about 1.5 m appart.
There's no such thing as eliminate. What reduction in vibration do you
need? What frequency. etc etc. The more details you give the less it
looks like 20 questions.
Two pumps pumping from an open (vented) vault/tank? Or are there suction inlets on one of the pumps that don't show? Are the two pipes entering the vault/tank in plan view dumping the two chemicals to be mixed (one is labelled filtered water)? Any idea on make and model of the pumps, sizes?
Are these pumps pumping from a float or level switch/sensor, and is slosh in the tank a possibility (enough for the pumps to suck air)? Air bubbles slugging their way thru static mixers will definitely cause some shaking.
How well are the mixing elements secured in the piping? Is the vibration a high freqency, maybe due to the elements twisting/flexing and banging on the pipe walls?
Or is it a lower frequency, with the whole string of pipe rattling and moving between mounts? This latter would point more towards surging/slugging and/or air aspiration from the pumps.
Since your description is lacking many critical details, we all end up
making educated guesses. I have a different guess than the others. I
assume that the vibration is high the entire time the pump is running,
not just at start-up. I
assume that the vibration that concerns you is in the horizontal run of
pipe in the pump discharge where the static mixers are mounted. I
assume that when you remove these static mixers, you are replacing them
with an equivalent length of pipe. Or perhaps they can be removed
separately, leaving the original pipe in place. (I know nothing about
static mixers) In either case, it sounds to me like a piping resonance
in that horizontal run. If so, all you have to do is de-tune it. The
piping has a natural frequency that corresponds to some frequency coming
from the pumps. This could be exited at pump run speed, vane pass
frequency or a multiple of either. Removal of the static mixers reduces
the mass of that line, which increases the natural frequency of the
pipe. This theory can be easily tested. Take a heavy bag of sand and
lay it across the pipe at the location with the highest vibration. If
the vibration goes away almost completely, then it could be
resonance. If so, any permanent modification that significantly changes
the stiffness or mass can detune the vibration response and "eliminate"
it. If you add a pipe support at mid-span, this could do the trick. If
my theory is correct, this would not transfer the vibration to another
part of the pipe. By changing the natural frequency of that section of
pipe, you would stop the resonant response. A further sign that this is
piping resonance would be to compare the piping vibration in two
directions. For example, if the piping vibration is very high up and
down, but very low side to side, this would suggest a resonance. You can
check for this with a coin. Hold the coin in your hand and run it along
the pipe. You will feel the coin chattering against the vibrating pipe
where the amplitude is highest. This will smooth out at locations (or
directions) where the amplitude is lower. A resonating pipe will take
on a mode shape which is usually a simply arc. The vibration would be
highest in the middle of the span and have nodes at each end with little
or no vibration.
If I am wrong about the location of the vibration or the conditions under which it exists, please correct me.
From the original1Check Valve.com
.
I was even thinking of putting in flexible couplings, but once again this may reduce vibration but not eliminate.
Does anyone know how to eliminate pipe vibration on stain less steel pipes? The current pipe support are about 1.5 m appart.
There's no such thing as eliminate. What reduction in vibration do you
need? What frequency. etc etc. The more details you give the less it
looks like 20 questions.
Two pumps pumping from an open (vented) vault/tank? Or are there suction inlets on one of the pumps that don't show? Are the two pipes entering the vault/tank in plan view dumping the two chemicals to be mixed (one is labelled filtered water)? Any idea on make and model of the pumps, sizes?
Are these pumps pumping from a float or level switch/sensor, and is slosh in the tank a possibility (enough for the pumps to suck air)? Air bubbles slugging their way thru static mixers will definitely cause some shaking.
How well are the mixing elements secured in the piping? Is the vibration a high freqency, maybe due to the elements twisting/flexing and banging on the pipe walls?
Or is it a lower frequency, with the whole string of pipe rattling and moving between mounts? This latter would point more towards surging/slugging and/or air aspiration from the pumps.
Since your description is lacking many critical details, we all end up
making educated guesses. I have a different guess than the others. I
assume that the vibration is high the entire time the pump is running,
not just at start-up. I
assume that the vibration that concerns you is in the horizontal run of
pipe in the pump discharge where the static mixers are mounted. I
assume that when you remove these static mixers, you are replacing them
with an equivalent length of pipe. Or perhaps they can be removed
separately, leaving the original pipe in place. (I know nothing about
static mixers) In either case, it sounds to me like a piping resonance
in that horizontal run. If so, all you have to do is de-tune it. The
piping has a natural frequency that corresponds to some frequency coming
from the pumps. This could be exited at pump run speed, vane pass
frequency or a multiple of either. Removal of the static mixers reduces
the mass of that line, which increases the natural frequency of the
pipe. This theory can be easily tested. Take a heavy bag of sand and
lay it across the pipe at the location with the highest vibration. If
the vibration goes away almost completely, then it could be
resonance. If so, any permanent modification that significantly changes
the stiffness or mass can detune the vibration response and "eliminate"
it. If you add a pipe support at mid-span, this could do the trick. If
my theory is correct, this would not transfer the vibration to another
part of the pipe. By changing the natural frequency of that section of
pipe, you would stop the resonant response. A further sign that this is
piping resonance would be to compare the piping vibration in two
directions. For example, if the piping vibration is very high up and
down, but very low side to side, this would suggest a resonance. You can
check for this with a coin. Hold the coin in your hand and run it along
the pipe. You will feel the coin chattering against the vibrating pipe
where the amplitude is highest. This will smooth out at locations (or
directions) where the amplitude is lower. A resonating pipe will take
on a mode shape which is usually a simply arc. The vibration would be
highest in the middle of the span and have nodes at each end with little
or no vibration.
If I am wrong about the location of the vibration or the conditions under which it exists, please correct me.
From the original1Check Valve.com
.
Your interpetation of B31.1 para 122.1.7(B)(B.1)
I know this is a piping code, but I posted this question here because it applies to Boiler External Piping.
In the above mentioned paragraph, it states: "The stop valve or cock shall comply with the requirements of (C.5) below."
para (C.5) states: ..."valves or cocks shall be bronze, cast iron, ductile iron or steel."
Question: since
only the stop valve is mentioned, does that mean I can use a stainless
check valve per para 107.1 as long as the material is listed in table
126.1?
Not so fast. The Code does not provide card blanch for materials to be
used in any environment or service just because materials are listed in
Table 126.1. The reference to C.5 applies to low temperature/pressure
boilers and if a stop valve is installed of the permitted materials, the
check valve should be close to the same material. Why would you want to
install a stainless steel check valve? Galvanic corrosion could be a
problem.
Have you heard of stress corrosion cracking in
austenitic grades of stainless steel at around 160 deg F and higher in
oxygenated, treated water?
From the original1Check Valve.com
.
In the above mentioned paragraph, it states: "The stop valve or cock shall comply with the requirements of (C.5) below."
para (C.5) states: ..."valves or cocks shall be bronze, cast iron, ductile iron or steel."
Question: since
only the stop valve is mentioned, does that mean I can use a stainless
check valve per para 107.1 as long as the material is listed in table
126.1?
Not so fast. The Code does not provide card blanch for materials to be
used in any environment or service just because materials are listed in
Table 126.1. The reference to C.5 applies to low temperature/pressure
boilers and if a stop valve is installed of the permitted materials, the
check valve should be close to the same material. Why would you want to
install a stainless steel check valve? Galvanic corrosion could be a
problem.
Have you heard of stress corrosion cracking in
austenitic grades of stainless steel at around 160 deg F and higher in
oxygenated, treated water?
From the original1Check Valve.com
.
Best way to stop air cylinder with a light curtain application?
What are your thoughts about the best way to stop air cylinder with a light curtain application? Lets say it's mounted vertically and is connected to a couple hundred pound load (i.e. enough to fall and hurt somebody or something).
Pneumatic valve choices and issues that I have heard of but I really don't fully understand the impact of them all:
1) 3-position-center-open.
---->The load will fall when the light curtain is broken.
---->Tooling might slam at the top position once system is re-energized.
2) 3-position-center-open with pilot-operated-check-valve on the bottom port of the cylinder
---->Response time to stop load might not be fast enough for application.
---->Load could drift up.
---->Tooling might slam at the top position once system is re-energized.
3) 3-position-center-blocked or pilot-operated-check-valves at both ends of the cylinder.
---->Response time to stop load might not be fast enough for application.
---->Cylinder might drift
---->Cylinder is locked in position. It will take a crowbar to move it, or you'd have to remove the pilot-operated-check-valves.
4) 3-position-center-pressurized.
---->Load will drift towards the rod end of the cylinder because the rod side of the piston has a smaller surface area, therefore will have less force than the force on the non-rod side of the piston.
5) 3-position-center-pressurized where each side of the cylinder is pressurized with a different pressure. When setup correctly it will balance the load by compensating for the different surfaces areas on the piston (i.e. rod side will need a higher pressure since it has a smaller surface area).
---->Response time very good
---->Complex and could be difficult to plumb.
Just curious what others have to say about this issue.
From the original1Check Valve.com
.
Pneumatic valve choices and issues that I have heard of but I really don't fully understand the impact of them all:
1) 3-position-center-open.
---->The load will fall when the light curtain is broken.
---->Tooling might slam at the top position once system is re-energized.
2) 3-position-center-open with pilot-operated-check-valve on the bottom port of the cylinder
---->Response time to stop load might not be fast enough for application.
---->Load could drift up.
---->Tooling might slam at the top position once system is re-energized.
3) 3-position-center-blocked or pilot-operated-check-valves at both ends of the cylinder.
---->Response time to stop load might not be fast enough for application.
---->Cylinder might drift
---->Cylinder is locked in position. It will take a crowbar to move it, or you'd have to remove the pilot-operated-check-valves.
4) 3-position-center-pressurized.
---->Load will drift towards the rod end of the cylinder because the rod side of the piston has a smaller surface area, therefore will have less force than the force on the non-rod side of the piston.
5) 3-position-center-pressurized where each side of the cylinder is pressurized with a different pressure. When setup correctly it will balance the load by compensating for the different surfaces areas on the piston (i.e. rod side will need a higher pressure since it has a smaller surface area).
---->Response time very good
---->Complex and could be difficult to plumb.
Just curious what others have to say about this issue.
From the original1Check Valve.com
.
2010年12月6日星期一
High Pressure Valve Vendors
I am collecting offers for high pressure valves for steam lines in natural gas power plant. Most manufacturers are limited to Class 2500 but I am looking for manufacturers who can build till Class 4500 and also using forged material.
Sizes are around 4-6-8".
I could only locate Raimondi and Intervalve of Tyco.
Except Tyco group, are there any other vendors that you could advise?
Aceco (acecovalves.com) makes high pressure ball valves using 4340
forged bar, up to 10 or 11,000 psi. They aren't flanged-end though,
they're what is called "compact manifold valves" for use in oilfield
piping systems. You can get them with weld-end attachments, but I don't
know if they have flanged-ends or not.
If it is a control valve that you are after, Severn Glocon / Severn
Unival have manufactured valves to API10000 and 15000 (so up to 15000
psi rated) from block forgings and hipped material. They specialise in
1-offs, so may be able to help with an ANSI 4500 rated valve.
From the original1Check Valve.com
Sizes are around 4-6-8".
I could only locate Raimondi and Intervalve of Tyco.
Except Tyco group, are there any other vendors that you could advise?
Aceco (acecovalves.com) makes high pressure ball valves using 4340
forged bar, up to 10 or 11,000 psi. They aren't flanged-end though,
they're what is called "compact manifold valves" for use in oilfield
piping systems. You can get them with weld-end attachments, but I don't
know if they have flanged-ends or not.
If it is a control valve that you are after, Severn Glocon / Severn
Unival have manufactured valves to API10000 and 15000 (so up to 15000
psi rated) from block forgings and hipped material. They specialise in
1-offs, so may be able to help with an ANSI 4500 rated valve.
From the original1Check Valve.com
Pump Warm Up Procedures And Hot Alignment
After a quick search of the forum I did not see much discussion of start-up procedures for hot pumps.
My question is three-fold regarding warm up:
How
quickly do you allow pumps to be warmed up? I've heard that most OEMs
suggest about 100F per hour to allow even thermal expansion.
How
do you warm pumps? I've heard about warm-up lines that bypass
discharge check valves, holes drilled in check valves, and operators
cracking the suction with a line to process sewer off the
discharge. How do you recommend regulating the speed at which the pump
is warmed up?
How far along in the warm-up procedure do you suggest performing a "hot alignment"?
The heat-up rate should be specified by the manufacturer. But, every
one I ever looked up was 100 °F per hour maximum. The criticality of
this depends on the specific pump. We have some fully lined slurry pumps
with hard chrome liners that tend to crack if heated up too fast. We
have some vertical sulfur pit pumps that will snap the shaft off because
of differential growth between the shaft and column if you heat them up
to quickly.
We use at least four methods for heating up hot
service pumps. Each has it own issues and depending on the
configuration of the pump, one may be superior to the others. For a
typical single stage overhung pump, we prefer to have a piped warm-up
line from the discharge that connects into the bottom of the case. This
will tend to give the best, most uniform heat up. If the pump is top
suction, top discharge and you drill the check valve or bypass the check
valve the flow can short-cut from the discharge line back up the
suction line and may not heat the case full to the bottom.
With
some of our big barrel pumps, it is defiantly better to have a bypass
piped around the check valve. We can't drill a hole in the check valve
because we would either get too much flow or we would have to drill a
very small hole that would plug off. With a piped bypass, we can
include a multi-orifice stack that can take the higher pressure drop
without eroding or plugging off. Otherwise, we could install a globe
valve in the bypass to regulate the heat up rate. We do not want to put
the warm up line to the bottom of the case on a barrel pump. The case
drain is in contact with the pump suction on some of these pumps. So,
once again, the flow could short-cut and not heat the entire pump up. By
bypassing the check valve, the flow has to pass through all stages of
the pump to get to the suction line.
For vertical in-line
pumps, vertical turbine pumps or two-stage, between bearings
configurations, a drilled check valve often works very well. This is
also our second alternative for single stage overhung pumps. As long as
the drilled hole is at least 3/16", and the service is clean enough to
not plug that up, it works well.
We have standards that require
that the pump temperature is within a certain differential from feed
drum temperature before the pump can be started. This varies from pump
to pump. But typically it is 40 °F to 80 °F.
I can't answer your
question about hot alignment since our policies do not allow it. It is
very difficult to do a good hot alignment with energy control policies
that require a block valve blocked and chained and all other sources of
energy blocked and locked. By the time we establish full energy control
and get a work permit, the pump will no longer be hot. Instead, we do
cold alignments with pre-determined offsets to allow for thermal
growth. If you are still allowed to do a hot alignment with open
valves, then the pump should be within about 50 °F of feed drum
temperature when you align it.
We have no process safety issues with a drilled check valve. It is a
back-flow path, but the flow is so low, that we have not seen any
situations where it could cause a significant process safety risk. Most
of our warm up lines are orificed so they don't have to make ongoing
adjustments. In some rare instances, they warm up the equipment by
flowing through to slop with a hose coming off a drain or vent
connection. In those, yes, they compare temperatures using an IR gun and
watch the time to stay within the heat-up rate limits called out in the
procedure.
I should comment that the drilled check option is
almost always used with pairs of pumps installed in parallel. One pump
is running and the other is being warmed up (or kept warm). In this
instance, there is no back-flow other than the short loop through the
off-line pump. In other words, any flow backwards through the pump being
warmed up passes up the suction line, crosses over into the running
pump and is pumped forward into the process. It does not backflow all
the way to the suction vessel. If the pump is unspared, there would
typically not be adequate pressure in the discharge system to back-flow
for warm up. We could not use a drilled check for an unspared charge
pump in a hydrotreater, for example. We could not allow high pressure
hydrogen to back-flow into the feed surge drum which is not rated for
hydrogen service. A pump in this service would have to be warmed up
using a line to slop passing hot feed forward through the pump.
We
are able to validate our calculated thermal offsets values at each
repair. If the vibration data shows that we have a good running
alignment, then the targets must be good. If the vibration shows a
residual misalignment problem, then we have to change the offset
values.
From the original1Check Valve.com
My question is three-fold regarding warm up:
How
quickly do you allow pumps to be warmed up? I've heard that most OEMs
suggest about 100F per hour to allow even thermal expansion.
How
do you warm pumps? I've heard about warm-up lines that bypass
discharge check valves, holes drilled in check valves, and operators
cracking the suction with a line to process sewer off the
discharge. How do you recommend regulating the speed at which the pump
is warmed up?
How far along in the warm-up procedure do you suggest performing a "hot alignment"?
The heat-up rate should be specified by the manufacturer. But, every
one I ever looked up was 100 °F per hour maximum. The criticality of
this depends on the specific pump. We have some fully lined slurry pumps
with hard chrome liners that tend to crack if heated up too fast. We
have some vertical sulfur pit pumps that will snap the shaft off because
of differential growth between the shaft and column if you heat them up
to quickly.
We use at least four methods for heating up hot
service pumps. Each has it own issues and depending on the
configuration of the pump, one may be superior to the others. For a
typical single stage overhung pump, we prefer to have a piped warm-up
line from the discharge that connects into the bottom of the case. This
will tend to give the best, most uniform heat up. If the pump is top
suction, top discharge and you drill the check valve or bypass the check
valve the flow can short-cut from the discharge line back up the
suction line and may not heat the case full to the bottom.
With
some of our big barrel pumps, it is defiantly better to have a bypass
piped around the check valve. We can't drill a hole in the check valve
because we would either get too much flow or we would have to drill a
very small hole that would plug off. With a piped bypass, we can
include a multi-orifice stack that can take the higher pressure drop
without eroding or plugging off. Otherwise, we could install a globe
valve in the bypass to regulate the heat up rate. We do not want to put
the warm up line to the bottom of the case on a barrel pump. The case
drain is in contact with the pump suction on some of these pumps. So,
once again, the flow could short-cut and not heat the entire pump up. By
bypassing the check valve, the flow has to pass through all stages of
the pump to get to the suction line.
For vertical in-line
pumps, vertical turbine pumps or two-stage, between bearings
configurations, a drilled check valve often works very well. This is
also our second alternative for single stage overhung pumps. As long as
the drilled hole is at least 3/16", and the service is clean enough to
not plug that up, it works well.
We have standards that require
that the pump temperature is within a certain differential from feed
drum temperature before the pump can be started. This varies from pump
to pump. But typically it is 40 °F to 80 °F.
I can't answer your
question about hot alignment since our policies do not allow it. It is
very difficult to do a good hot alignment with energy control policies
that require a block valve blocked and chained and all other sources of
energy blocked and locked. By the time we establish full energy control
and get a work permit, the pump will no longer be hot. Instead, we do
cold alignments with pre-determined offsets to allow for thermal
growth. If you are still allowed to do a hot alignment with open
valves, then the pump should be within about 50 °F of feed drum
temperature when you align it.
We have no process safety issues with a drilled check valve. It is a
back-flow path, but the flow is so low, that we have not seen any
situations where it could cause a significant process safety risk. Most
of our warm up lines are orificed so they don't have to make ongoing
adjustments. In some rare instances, they warm up the equipment by
flowing through to slop with a hose coming off a drain or vent
connection. In those, yes, they compare temperatures using an IR gun and
watch the time to stay within the heat-up rate limits called out in the
procedure.
I should comment that the drilled check option is
almost always used with pairs of pumps installed in parallel. One pump
is running and the other is being warmed up (or kept warm). In this
instance, there is no back-flow other than the short loop through the
off-line pump. In other words, any flow backwards through the pump being
warmed up passes up the suction line, crosses over into the running
pump and is pumped forward into the process. It does not backflow all
the way to the suction vessel. If the pump is unspared, there would
typically not be adequate pressure in the discharge system to back-flow
for warm up. We could not use a drilled check for an unspared charge
pump in a hydrotreater, for example. We could not allow high pressure
hydrogen to back-flow into the feed surge drum which is not rated for
hydrogen service. A pump in this service would have to be warmed up
using a line to slop passing hot feed forward through the pump.
We
are able to validate our calculated thermal offsets values at each
repair. If the vibration data shows that we have a good running
alignment, then the targets must be good. If the vibration shows a
residual misalignment problem, then we have to change the offset
values.
From the original1Check Valve.com
Water Injection for NA Engines, any benefit?
Could anybody let me know if water injection can help to reduce the
intake air temperature significantly in NA engines? I heard that it is
mostly used in Turbocharged engines.
And if it is useful Practically, is there any way to make a DIY version on a low budget?/filter
Engine: 1.6L, 112 BhP, compression ratio: 10.5.
There is a way to demonstrate to yourself the effects of water vapor on the normal small gasoline engines , used on todays midsized sedans or trucks .
You will have some positive results, but remember these results will not happen all the time . Like many have mentioned,, Winter months can freeze water and you will not get things going again until the system thaws out .
Simply install a small Ultrasonic water mist generator upstream of the intake manifold , behind the sensors and air filter .. They vary in size and this will take some calculations , and/or engineering data to determine the best Mist generator to use . In other words engineering data along with experiamentation will determine how much Distilled Water can be used without hurting the engine .
Ultrasonic Miss Generators are Pizeo Electric Transducers ,, typically Steiner and Martin type , (Out of Florida) They have a long life of 3000 or more hours. They atomize Water ,, and it can be installed in such a way to be sucked into the intake manifold .. No re-condensing occurs in the Manifold , due to it is too hot ,a Baff plate or Mistermat can be used to be sure not to put too much Water in the system ..
The idea is to keep the manifold hot enough to super heat the atomized water , this is easily done in summer months, but not so easy in the extreme colds of the north . Down here in the south ,or Texas we use Atomized Distilled water, Mixed with ambient Air .
We do not turn on the switch to atomize the water until temperatures are up in engines , We do not run it on rainy days ,, or Extreme cold conditions .
A simple level control system Keeps the Ultrasonic Pizeo Electric Transducers covered with about 1.5 inches of water ,, so this may not work to well in severe inclines .. The system automatically shuts down on a lack of water level .
Results normally are from 10-20% increase in fuel economy, with a slight increase in Power .. Nothing is changed on the engine , except maybe making sure you have a 195 or better engine coolant thermostat .. A system like this will cost about $70-$100 to manufacture at home ,, and a few hours work .
Results vary depending upon many factors ,, and we are not PHD engineers , but back yard Novice inventors .. We simply try and find simple cost effective ways to improve Fuel economy While not destroying our expensive machines .. Atomized Distilled water cost about 50 cents a gallon , consumption ranges from 1 liter-- 4 liters per hour, on the highway. I have a 2000 Buick Lesabre , and I get ruffly an average of 35 MPG on the highway using atomized Distilled water as an aid to Regular unleaded fuel . I combine the gasoline volume , and Water volume , in liquid gallons , to come up with the correct figure .
I am employed by Shell Oil, Shell will not give me a Patent release to Patent my device , due to it will hurt their bottom line . ( though Shell Oil has had nothing to do with this invention ) Ultrasonic Mist generators can work to atomize water and increase fuel economy without hurting the engine . But it must be installed at the right location in the intake manifold . And used under the correct conditions. WE ( myself and other professional Machinist/technicians ) have done extensive research , along with engineers and are convinced the technology exist to perfect this system . Hopefully real PHD engineers one day will accept Water injection as a simple means to increase Fuel economy .
The water droplets are 1 micron in size ,, and quickly split even smaller when heated. Expansion is 1600 times .. Also we have experimented with fuels using Ultasonics for atomization , also producing 1 micron or smaller size particals , small enough to pass through Fuel injectors , then the cavitation bubbles collapse ,and aid in mixing better with Oxygen .
We are just stubborn Technicians , and are still looking to Improve our system .
From the original1Check Valve.com
intake air temperature significantly in NA engines? I heard that it is
mostly used in Turbocharged engines.
And if it is useful Practically, is there any way to make a DIY version on a low budget?/filter
Engine: 1.6L, 112 BhP, compression ratio: 10.5.
There is a way to demonstrate to yourself the effects of water vapor on the normal small gasoline engines , used on todays midsized sedans or trucks .
You will have some positive results, but remember these results will not happen all the time . Like many have mentioned,, Winter months can freeze water and you will not get things going again until the system thaws out .
Simply install a small Ultrasonic water mist generator upstream of the intake manifold , behind the sensors and air filter .. They vary in size and this will take some calculations , and/or engineering data to determine the best Mist generator to use . In other words engineering data along with experiamentation will determine how much Distilled Water can be used without hurting the engine .
Ultrasonic Miss Generators are Pizeo Electric Transducers ,, typically Steiner and Martin type , (Out of Florida) They have a long life of 3000 or more hours. They atomize Water ,, and it can be installed in such a way to be sucked into the intake manifold .. No re-condensing occurs in the Manifold , due to it is too hot ,a Baff plate or Mistermat can be used to be sure not to put too much Water in the system ..
The idea is to keep the manifold hot enough to super heat the atomized water , this is easily done in summer months, but not so easy in the extreme colds of the north . Down here in the south ,or Texas we use Atomized Distilled water, Mixed with ambient Air .
We do not turn on the switch to atomize the water until temperatures are up in engines , We do not run it on rainy days ,, or Extreme cold conditions .
A simple level control system Keeps the Ultrasonic Pizeo Electric Transducers covered with about 1.5 inches of water ,, so this may not work to well in severe inclines .. The system automatically shuts down on a lack of water level .
Results normally are from 10-20% increase in fuel economy, with a slight increase in Power .. Nothing is changed on the engine , except maybe making sure you have a 195 or better engine coolant thermostat .. A system like this will cost about $70-$100 to manufacture at home ,, and a few hours work .
Results vary depending upon many factors ,, and we are not PHD engineers , but back yard Novice inventors .. We simply try and find simple cost effective ways to improve Fuel economy While not destroying our expensive machines .. Atomized Distilled water cost about 50 cents a gallon , consumption ranges from 1 liter-- 4 liters per hour, on the highway. I have a 2000 Buick Lesabre , and I get ruffly an average of 35 MPG on the highway using atomized Distilled water as an aid to Regular unleaded fuel . I combine the gasoline volume , and Water volume , in liquid gallons , to come up with the correct figure .
I am employed by Shell Oil, Shell will not give me a Patent release to Patent my device , due to it will hurt their bottom line . ( though Shell Oil has had nothing to do with this invention ) Ultrasonic Mist generators can work to atomize water and increase fuel economy without hurting the engine . But it must be installed at the right location in the intake manifold . And used under the correct conditions. WE ( myself and other professional Machinist/technicians ) have done extensive research , along with engineers and are convinced the technology exist to perfect this system . Hopefully real PHD engineers one day will accept Water injection as a simple means to increase Fuel economy .
The water droplets are 1 micron in size ,, and quickly split even smaller when heated. Expansion is 1600 times .. Also we have experimented with fuels using Ultasonics for atomization , also producing 1 micron or smaller size particals , small enough to pass through Fuel injectors , then the cavitation bubbles collapse ,and aid in mixing better with Oxygen .
We are just stubborn Technicians , and are still looking to Improve our system .
From the original1Check Valve.com
Temp range for an exhaust valve?
I'm hot-rodding a Toyota 4AGZE, which is a 1600cc 4-valve supercharged motor. I would like to test the exhaust sealing ability of the valves by heating a closed valve with a propane torch (and then pressurizing the valve from the back side). Can someone give me a ball-park figure for the normal operating temperature range for an exhaust valve in such a motor? Probably the operating range of an exhaust valve(API Cast Steel Valves) for a generic IC gasoline engine would be close enough for what I am doing.
It seems to me what you are trying to do is a bit counter intuitive. To
start, I doubt you will be able to get an exhaust valve, assembled in a
cylinder head, anywhere near hot enough with a "propane torch"...An
oxy-acetylene torch, perhaps. Second, you are "pressurizing" the ex
valve from the wrong side. My question is WHY? There are several
other, more conventional testing methods to check the valve seal...comp
ck, leak down and, even just sticking a vacuum cleaner hose in the ex
port and using a stethoscope to listen for leaks. As primitive as that
sounds, I find it more reliable than "pressurizing the valve from the
back side".
The primary path for heat transfer in an exhaust valve is through its
contact with the valve seat. And since your exhaust valve is an
axisymmetric part with a relatively uniform input of heat flux, it
should not experience much distortion with temperature. The heat input
into the valve varies during an engine cycle, due to things like exhaust
gas pressure and temperature, intake/exhaust flow overlap, A/F ratios,
and engine load.
The leakage rate of your seated exhaust valve
will be more affected by the heat transfer rate between the seat and
head than anything else. With a small valve head diameter, overheating
should not be a problem. Your exhaust valves should not see temps
higher than about 1300degF, even with high levels of supercharge. But
if you want to check exhaust valve leakage at operating temps, you will
need to make sure that the valve, seat, head, etc. are all at the
correct temperature, not just the exhaust valve.
Additionally,
pressure leakage past the piston rings is likely much more detrimental
than any leakage past the exhaust valve seats. So maybe you're efforts
might be misplaced.
From the original1Check Valve.com
It seems to me what you are trying to do is a bit counter intuitive. To
start, I doubt you will be able to get an exhaust valve, assembled in a
cylinder head, anywhere near hot enough with a "propane torch"...An
oxy-acetylene torch, perhaps. Second, you are "pressurizing" the ex
valve from the wrong side. My question is WHY? There are several
other, more conventional testing methods to check the valve seal...comp
ck, leak down and, even just sticking a vacuum cleaner hose in the ex
port and using a stethoscope to listen for leaks. As primitive as that
sounds, I find it more reliable than "pressurizing the valve from the
back side".
The primary path for heat transfer in an exhaust valve is through its
contact with the valve seat. And since your exhaust valve is an
axisymmetric part with a relatively uniform input of heat flux, it
should not experience much distortion with temperature. The heat input
into the valve varies during an engine cycle, due to things like exhaust
gas pressure and temperature, intake/exhaust flow overlap, A/F ratios,
and engine load.
The leakage rate of your seated exhaust valve
will be more affected by the heat transfer rate between the seat and
head than anything else. With a small valve head diameter, overheating
should not be a problem. Your exhaust valves should not see temps
higher than about 1300degF, even with high levels of supercharge. But
if you want to check exhaust valve leakage at operating temps, you will
need to make sure that the valve, seat, head, etc. are all at the
correct temperature, not just the exhaust valve.
Additionally,
pressure leakage past the piston rings is likely much more detrimental
than any leakage past the exhaust valve seats. So maybe you're efforts
might be misplaced.
From the original1Check Valve.com
2010年11月21日星期日
3d model of gate,check valve
Anybody knows where I can 3d models of all different types(Gate,check,Globe, Pressure relief, 3 way,etc.ball valves)of valves of different sizes ranging from 1in to 12in.? I checked 3d central but those models are not enough.
Please provide me some info.
just for the heck of it, did you try mc master carr? they have a lot of models.
Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2009 SP 4.1
Dell 490 XP Pro SP 2
Xeon CPU 3.00 GHz 3.00 GB of RAM
nVida Quadro FX 3450 512 MB
3D Connexion-SpaceExplorer
From the original1CheckValve
.
Please provide me some info.
just for the heck of it, did you try mc master carr? they have a lot of models.
Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2009 SP 4.1
Dell 490 XP Pro SP 2
Xeon CPU 3.00 GHz 3.00 GB of RAM
nVida Quadro FX 3450 512 MB
3D Connexion-SpaceExplorer
From the original1CheckValve
.
Air-Operated Double Diaphragm Pump Sizing
Whenever sizing an Air-Operated Double Diaphragm pump (or any pump in
that matter), do you size for just the discarge head? Or do you size
the pump (determine operating point on pump curve) by using:
Head=Discharge head-Suction head.
We use a lot of these pumps. Almost all of ours are 1" pumps. We use
them in all kinds of intermitant services. We have pressure regulators
on the compressed air to the pumps. That controls the total allowable
discharce pressure (Discharge=Supply) and we also have a ball valve on
the air line that we throttle to slow or speed up the pump. It is
pretty crude but effective for what we do. If you actually have a standard application maybe you
would be more interested in a vane pump or centrifugal pump but for
miscellaneous pumping needs the 1" or 2" diaphragm pumps work well.
You may want to switch pumps as MikeHalloran suggested. You will be
happier with something like an LMI pump for real small flows or a
Pulsafeeder pump for larger flows. Then control based on the number of
strokes, or time which ever is easier for you. The diaphragm pump is
not going to give you what you want. Maybe you could fill an
intermediate tank from the tote and then pump the whole intermediate
tank into the reactor but that is more operator intensive.
From the original1CheckValve
.
that matter), do you size for just the discarge head? Or do you size
the pump (determine operating point on pump curve) by using:
Head=Discharge head-Suction head.
We use a lot of these pumps. Almost all of ours are 1" pumps. We use
them in all kinds of intermitant services. We have pressure regulators
on the compressed air to the pumps. That controls the total allowable
discharce pressure (Discharge=Supply) and we also have a ball valve on
the air line that we throttle to slow or speed up the pump. It is
pretty crude but effective for what we do. If you actually have a standard application maybe you
would be more interested in a vane pump or centrifugal pump but for
miscellaneous pumping needs the 1" or 2" diaphragm pumps work well.
You may want to switch pumps as MikeHalloran suggested. You will be
happier with something like an LMI pump for real small flows or a
Pulsafeeder pump for larger flows. Then control based on the number of
strokes, or time which ever is easier for you. The diaphragm pump is
not going to give you what you want. Maybe you could fill an
intermediate tank from the tote and then pump the whole intermediate
tank into the reactor but that is more operator intensive.
From the original1CheckValve
.
Ring Check Valve??
An inspection of input voltage vs flow rate properties of a hydraulic servo valve Im impressing a triangular wave (frequency 0.01Hz amplitude +-10v) and plotting voltage and flow on an X Y graph. I have to set the main pressure so that the valve pressure fall at the flow rate when the input voltage is 10v (rated flow rate)is 2Bar.
Valve pressure fall=Ps-(Pa-Pb)-Pt,Ps:Main pressure,Pa:A port pressure
Pb:B port pressure,Pt:T port pressure
The different port placing, being no servo engineer I dont directly take the diagram connection a-b and t.
I have an inkling though about your question.
From the original1CheckValve
.
Valve pressure fall=Ps-(Pa-Pb)-Pt,Ps:Main pressure,Pa:A port pressure
Pb:B port pressure,Pt:T port pressure
The different port placing, being no servo engineer I dont directly take the diagram connection a-b and t.
I have an inkling though about your question.
From the original1CheckValve
.
2010年11月18日星期四
When to use "pump control cone valves"?
Most of the American water works have "pump control cone or ball valves"
acting also as a check valves behind their pumps. In Europe the
standard seems to be a non slam nozzle check valve plus an isolation
gate or butterfly valve. -which seems to be the less expensive design.
Can anyone tell me the reason when to choose the cone valves and when to choose check valves?
Can I simply replace a cone valve by a check and butterfly valve?
Is the 'cone' valve acting as a pressure reducing valve?
Most
installations I am famialar with use a diaphram operated globe valve
such as Cla for pressure control unless the pump is on a drive.
The
configuation of the control valve can provide a whole list of pressure
and flow control functions depending upon the installation.
It depends on the hydraulics of the application. The fluid velocity, the numbers of start-stops of the pumps, the number of pumps, the size of the water distribution system, and the pressures in the system all have an effect on the hydraulics.
Opening, closing or regulating valves or pumps starting and stopping, usually causes surges in pipelines carrying liquids. These surges, also called hydraulic transients may range in importance from a slight pressure or velocity change to sufficiently high pressure or vacuum to rupture the piping system, to damage pumping equipment and cause extensive shutdown time. Water hammer, a result of hydraulic transients, will occur when the total surge pressure exceeds approximately twice the value of the static pressure in the system when the fluid is at rest.
Detailed pipeline surge analysis by an expert should be considered under the following design conditions:
(1) Generally, if the interaction of pump station, piping system, valves and control system is complex case following a power failure or during startup.
(2) If power failure at the pump station would result in significant reverse flow, which can check valves or causes a fluid rejoinder surge. In a system with a flat pipeline profile, reverse flow are usually not significant. In a system where the pumps work against a significant static lift, surge pressures can be many times the maximum steady state operating pressure.
(3) If the pipeline profile has significant intermediate high points where the fluid may separate, following power failure, and result in high surge pressures upon rejoining.
(4) If the pump station or individual pump intake suction through a pipeline of significant length (several hundred feet) a power failure may result in high-pressure heads. For pumps located immediately adjacent to storage tanks, suction line pressure transients are usually insignificant.
(5) If the pump station is equipped with discharge check valves and air vessels, the check valves may be slammed shut by the air vessel or parallel-connected pumps following power failure.
(6) If the preliminary calculations indicate that surge control equipment is required in the system, optimum performance and surge control equipment selection can be established through detailed surge analysis. Surge control system analysis should generally be performed for vertical turbine valve installations and any pump installation where individual pump capacity exceeds 500 gum.
Pump control valves function as part of a surge control system including valve, power and manual valve, operators, accumulator, sensing and recording devices. This system automatically prevents water hammer in starting and stopping of pumps should include safety features in its design to prevent damage from malfunctioning equipment.
If you have no concerns at all about surge pressure or water hammer, then go ahead and use the check valve and butterfly.
If you have concerns about surge pressures or water hammers with the starting and stopping of pumps, then you would want to use the pump pressure control valves. The pump pressure control valves are the "electric check valves", and the rotary ball valves ("cone valves").
Pump pressure control valves are mainly used to regulate out the pressure surges that occur in starting and stopping of pumps. The pump pressure control valves will remain closed during pump startup until the pump discharge pressure reaches the valve’s set-point. This minimizes pressure fluctuation when the pump goes online.
When the pump shuts down, the pump pressure control valves close slowly (unlike a check valve). The slamming of a check valve may cause a water hammer. During an emergency such as a power failure, the pump pressure control valves will have a rapid controlled closing which will also tend to minimize pressure surges.
The cone valves can be optionally automated in order to control pump discharge pressure. If you are concerned about headloss through the valves, the cone valves are used because the pressure drop across the valves is minimal.
From the original1CheckValve
.
acting also as a check valves behind their pumps. In Europe the
standard seems to be a non slam nozzle check valve plus an isolation
gate or butterfly valve. -which seems to be the less expensive design.
Can anyone tell me the reason when to choose the cone valves and when to choose check valves?
Can I simply replace a cone valve by a check and butterfly valve?
Is the 'cone' valve acting as a pressure reducing valve?
Most
installations I am famialar with use a diaphram operated globe valve
such as Cla for pressure control unless the pump is on a drive.
The
configuation of the control valve can provide a whole list of pressure
and flow control functions depending upon the installation.
It depends on the hydraulics of the application. The fluid velocity, the numbers of start-stops of the pumps, the number of pumps, the size of the water distribution system, and the pressures in the system all have an effect on the hydraulics.
Opening, closing or regulating valves or pumps starting and stopping, usually causes surges in pipelines carrying liquids. These surges, also called hydraulic transients may range in importance from a slight pressure or velocity change to sufficiently high pressure or vacuum to rupture the piping system, to damage pumping equipment and cause extensive shutdown time. Water hammer, a result of hydraulic transients, will occur when the total surge pressure exceeds approximately twice the value of the static pressure in the system when the fluid is at rest.
Detailed pipeline surge analysis by an expert should be considered under the following design conditions:
(1) Generally, if the interaction of pump station, piping system, valves and control system is complex case following a power failure or during startup.
(2) If power failure at the pump station would result in significant reverse flow, which can check valves or causes a fluid rejoinder surge. In a system with a flat pipeline profile, reverse flow are usually not significant. In a system where the pumps work against a significant static lift, surge pressures can be many times the maximum steady state operating pressure.
(3) If the pipeline profile has significant intermediate high points where the fluid may separate, following power failure, and result in high surge pressures upon rejoining.
(4) If the pump station or individual pump intake suction through a pipeline of significant length (several hundred feet) a power failure may result in high-pressure heads. For pumps located immediately adjacent to storage tanks, suction line pressure transients are usually insignificant.
(5) If the pump station is equipped with discharge check valves and air vessels, the check valves may be slammed shut by the air vessel or parallel-connected pumps following power failure.
(6) If the preliminary calculations indicate that surge control equipment is required in the system, optimum performance and surge control equipment selection can be established through detailed surge analysis. Surge control system analysis should generally be performed for vertical turbine valve installations and any pump installation where individual pump capacity exceeds 500 gum.
Pump control valves function as part of a surge control system including valve, power and manual valve, operators, accumulator, sensing and recording devices. This system automatically prevents water hammer in starting and stopping of pumps should include safety features in its design to prevent damage from malfunctioning equipment.
If you have no concerns at all about surge pressure or water hammer, then go ahead and use the check valve and butterfly.
If you have concerns about surge pressures or water hammers with the starting and stopping of pumps, then you would want to use the pump pressure control valves. The pump pressure control valves are the "electric check valves", and the rotary ball valves ("cone valves").
Pump pressure control valves are mainly used to regulate out the pressure surges that occur in starting and stopping of pumps. The pump pressure control valves will remain closed during pump startup until the pump discharge pressure reaches the valve’s set-point. This minimizes pressure fluctuation when the pump goes online.
When the pump shuts down, the pump pressure control valves close slowly (unlike a check valve). The slamming of a check valve may cause a water hammer. During an emergency such as a power failure, the pump pressure control valves will have a rapid controlled closing which will also tend to minimize pressure surges.
The cone valves can be optionally automated in order to control pump discharge pressure. If you are concerned about headloss through the valves, the cone valves are used because the pressure drop across the valves is minimal.
From the original1CheckValve
.
2010年11月16日星期二
Ball Valves versus Triple Offset Butterfly
Has anyone had to justify either case. I'm aware of the TOSV cost, weight and torque differences between the two, but lacking butterfly valve total cost of ownership info. I'd like to understand the TOSV issues for 8" - 54" range 150/300/600# and anything in LNG service to would be appreciated.For a given size, a ball valve will be larger and heavier than a TOBV. Even when one orders the "Quarter-Turn Gate" valves that have the same B16.10 end-to-end as is customarty for Ball valves, there is not as much metal in a TOBV not as much machining. OTOH: the laminated seal rings commonly used in a TOBV are a tad on the expensive side to manufactureCapacity: TOBVs have a beefy disk assembly that hangs out in the middle of the flow stream. Cv is definintely reduced. TOBVs are offered in class 600, 900, and even 1500. WHen the disk is supported by enough shaft to withstand class 1500 differential pressure, there's not really a lot of hole left with the valve open. It becomes full of large diameter shaft and beefy disk. Ball valve can be supplied full port, with trunnion bearings that can withstand any pressure class without affecting capacity.
From the original1checkvalve
.
From the original1checkvalve
.
valve for a DIY motorized valve control
I've built a small ucontroller based motorized valve which uses a stepper motor to drive a valve (small, 1/2" valve). The valve sits on a bypass loop which is connected to a rotary pump. The rotary pump produces 9bar of pressure and the valve on the bypass loop is there to lower this pressure when needed. I know this might sound a bit strange but it's a specific application, and what's more important, it's DIYed as I was trying to keep the costs to a minimum.At the beginning of the project I was planning to use a ball valve, but now I see it might be quite hard as the torque needed to move the valve is quite high. The motor is connected with the valve using gears and the high torque is ripping the gears from the spindles (held with grub screws) of the motor/valve. I was thinking of using a gate valve which needs very little torque to move, but read that it shouldn't be used for throttling. I was also thinking of using a needle valve, but those are quite expensive and I haven't got any guarantee that the torque is going to be low on them anyway.So the question is, what would you recommend for this application? The things I'm looking for:- quite small adjustment range (something I liked about the ball valve)- low torque- low price- food-safeIs it possible to get ball valves that have low torque and don't get stuck after a long time of no-use? Or perhaps lubricate them somehow?
From the original1checkvalve
.
From the original1checkvalve
.
What is disk facing valve and vavle body seat ring (gate valve) for?
I am doing a analysis of the component in the gate valve and this two ring confuse me. Seat ring: ring forming a seat, eg. the part of the valve where the closing element 'sits down' or fit against to close the valve.The moving gate is here the closing (moving) element. A part forming the seat can by definition never be mounted on the closing (moving) element, only on the counterpart (on the valve body).NB! For all valves (part of) the sealing is mounted on the moving closing element (or originates from prepared surface of..), and is in some cases held in place on the closing element by a ring (clamping ring). This is then often given names as seat sealing or seat sealing clamping ring or similar. This must be understood as a sealing construction FOR the seat, and not confused with the seat or seat ring.
From the original1checkvalve
.
From the original1checkvalve
.
1/4" Plastic Normally Open Solenoid Valve
This is a little different to many of the valves discussed here, but I am sure someone has had experience with these.I require a 1/4" BSP female plastic solenoid valve. It needs to be 12vDC, and to have minimal exposed metal (preferably none as the marine environment will kill it quickly). The challenging part is it must be NORMALLY OPEN. It must also be cheap (<8USD - purchasing 200 PA).It is vital to be normally open as if power is removed, there is a risk of sinking the vessel.I have spent a large amount of time on google searching for these to minimal success. I have found a single valve that is adequate (R.P.E srl, Italy), but the price is a little high.The most common applications for these is irrigation, coffee machines, home appliances etc, but a lot of these are not designed for exposed operation.The design is for a vent to atmosphere to break a syphon on a marine vessel.Medium is atmospheric air, but must handle salt-laden air, salt spray, and salt water, and associated buildup with this type of environment.Pressure is -10psi to 300psi (valve must withstand not operate). Operation is at ambient pressure.Flowrate is <10 lpm.I am not interested in metal valves (even though they are capable of doing the job), as we are a plastic fitting manufacturer extolling the virtues of non-metallic fittings. It would be unwise from a marketing point of view to say 'but in same cases it is ok'.I am happy with regards to meeting certification requirements, and take UL as a nice to have but not required. DNV/Lloyds certification is not required.
From the original1checkvalve
.
From the original1checkvalve
.
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