What kind of valve will do this?
What kind of valve will do this?
(OP)
I am building a system which involves an increase in internal pressure via an air tank in order to extend a series of telescoping tubes, and a subsequent full release of pressure back to atmosphere. For safety reasons I need the release to happen due to the internal pressure reaching a certain point, and for the exaust valve to stay open until pressure has been fully equalized.
The system is carry-able and small, and operates at low pressures (<50 psi most likely).
Other than using rupture discs, is there a kind of valve that will do this?
The system is carry-able and small, and operates at low pressures (<50 psi most likely).
Other than using rupture discs, is there a kind of valve that will do this?





RE: What kind of valve will do this?
Often, people get too clever with their problem description because they don't want us to steal their great ideas. If there is more to it than I've addressed, you'll have to give us more information.
David
RE: What kind of valve will do this?
RE: What kind of valve will do this?
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David
RE: What kind of valve will do this?
RE: What kind of valve will do this?
thanks!
RE: What kind of valve will do this?
What it sounds like you need is what is commonly known as a a 3/2 way solenoid valve. This valve will have a P port (to which your source of pressurized air will be connected), an A port (which you connect to your device, and a vent. When energized, P will be connected to A and you'll pressurize your device. When de-energized, P will connect to vent. This is the standard valve used for single-acting actuators, which your device would seem to be.
3/2 way solenoid valves are cheap and plentiful, and are available in a wide range of sizes (Cv values, i.e. affecting how fast your actuator will pressurize and de-pressurize). They are available both pilot operated and direct acting- a pilot operated valve for your situation will be cheaper and will take less power.
RE: What kind of valve will do this?
I think I'm good then! thanks guys!
RE: What kind of valve will do this?
Ted
RE: What kind of valve will do this?
A 3/2 way solenoid valve is distinguished from a true 3-way direct acting solenoid valve in that there always must be pressure at the P port for the thing to work, since the pressure at the P port is used to operate a pilot (such as to drive a spool back and forth as hydtools mentions- but there are other types of pilots- not all solenoid valves are spool design).
A true or "universal" 3 way solenoid valve can have the supply pressure at any port, and doesn't need pressure at any port to function. They usually have big coils and small Cvs and modest shut-off pressures.
RE: What kind of valve will do this?
RE: What kind of valve will do this?
JMW
www.ViscoAnalyser.com
RE: What kind of valve will do this?
You can actuate this with two separate signals using a latching relay, if you don't want to maintain the solenoid hold current throughout the period where the actuator is pressurized.
If what you really want is a valve to pressurize the actuator then block in the air (once a certain extension or pressure is reached), and a separate valve to vent the air from the actuator, then you need two separate 2/2 way solenoid valves.