Valve / Actuator Air Consumption

It is not very clear what you want to ask....pls explain in detail....else we cant answer properly

Not too sure here, but I'd pose this question to a valve supplier who speaks your language.

Or may be you should be able to understand valve dynamics first before putting this brilliant answer

It depends on pressure, resistance from spring if present and from flow forces, on seals friction (type, material, lubrication,..), on valve design and several other factors and of course how big is the area of the controlling valve (pilot) or mass of moving equipment....and so on!

The flow as function of above mentioned variables can be sub-critical or critical if pressure drop at pilot valve is under or over the critical threshold. At the stroke end the flow is sub-critical if the sum of resistant forces is big with respect to the pressure force.

As you see even if one looks at details with respect to dynamics of a piloted valve the answer is not simple and the only correct way is to make a full simulation of the system and get from it the displacement-time curve for a given supply pressure.

From an other point of view the valve is in a control loop and will react to the disturbance amplitude and at the settings of your controller (PID or other types) so that if you do not know the transfer function of the valve it is at least very difficult to estimate its reaction.

Actually Our Mech Discipline engineers need to do the sizing for Air Compreessor they want the total air consumnption for all the valves .

Vendor has sized the valve and actuator and has provided the Voulme of Actuator ,

Based on which I can find the consumption for 01 stroke , But my problem is that I want Consumption for 01 min (SCFM), HonestLY I dont know how many strokes it will do in 01 min .I have asked the licensor for the details Apart from saying Continous Service I am not able to gather much data .

2) May I also know how accurate Thumb Rule is (10 SCFM/Valve)

Pity Some People depend on all the inputs from Vendor side

Regards

Jose

You might make some educated guesses, as does the guy in the 2nd post in this thread:

http://www.eng-tips.com/viewthread.cfm?qid=157377