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
.
2010年11月21日星期日
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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