pressure regulator/back pressure regulator

[CH5OH]

I am looking for a control valve supplier, able to deliver diafragm operated control valves.
objective: to control the pressure of a nitrogen/oil filled vessel A, so it follows the pressure in another vessel B.
if the pressure in vessel B rises,a N2 supply line (20bar) fills vessel A through a pressure regulating valve.
if the pressure drops in vessel B,a back pressure regulating valve vents of vessel A to atmosphere.
so the maximum pressure deviation between the to vessels is defined by the preload of the valve springs (to be less or equal to 0.1 bar)
nowadays it seems you need a delta P measurement 4-20mA, an electronic controller, split range valve setup and a compressed air supply (lucky me, I don't need a window based valve operating program, with a yearly upgrade

problem is to find two valves, so the whole system can be controlled pneumatically.
pressure regulating valve:
-inlet pressure 20 barg
-maximum flow 100kg/h N2
-pressure range 1 to 16 barg
-spring preload 0.1 bar

back pressure regulating valve:
-maximum inlet pressure 20 barg
-maximum flow 100kg/h N2 or 2 l/h oil
-pressure range 1 to 16 barg
-spring preload 0.1 bar

300pound flanges, 1/2"

 

[BigInch]

Why not connect the two vessels together feeding with the same supply.


**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

http://virtualpipeline.spaces.live.com/

 

[CH5OH]

because they aren't there,
its an simplified vieuw of a gas compressor oil seal chamber, leaking oil passed a primairy labyrinth seal
the objective is to keep the sour oil drain chamber, which is between oil seal and laby on the same pressure as the compressor, so at all times a same pressure exist on both sides of laby. connecting the two volumes would somewhat nihilate the purpose of the sealing system

 

[BigInch]

Make a diagram and post it on the gas compression forum.

**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

http://virtualpipeline.spaces.live.com/