Does such a relief valve exist?
Does such a relief valve exist?
(OP)
I am searching for a relief valve for an argon and/or helium laboratory aparatus. We have an expensive piece of equipment in the circuit that we do not want to over pressurize. The pressure that we have determined to be the maximum is .03 psig. Have any of you guys used a relief valve (preferably a pop safety) or rupture disk in this low range.
I appreciate any info
Thanks,
Dustin Biber
Optivus Technology Inc.
I appreciate any info
Thanks,
Dustin Biber
Optivus Technology Inc.





RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
You might want to look at these sites.
www.halky-roberts.com
www.agmcontainer.com
High precision, low pressure valves.
I have used products from both manufactures with very good results.
Good Luck
pennpoint
RE: Does such a relief valve exist?
Sorry I miss-typed my first link. It should have been:
www.halkey-roberts.com
Regards
pennpoint
RE: Does such a relief valve exist?
0.03 psi is about 1 inch of water if I did the conversion right. For a laboratory setup, would it make sense to bend some glass tubing such that it holds 1 inch of water? Hook it up to your apparatus and if the pressure exceeds the 1 inch of water it simply blows the water out of the tube. Just keep an eye on the water level and refill it when it evaporates. We have some similar devices here (though industrial sized!) which blow at 1.8 psig.
jt
RE: Does such a relief valve exist?
The more you learn, the less you are certain of.
RE: Does such a relief valve exist?
Regards,
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
I like the idea of a sensing device interacting to prevent the overpressure. I currently require a pressure transducer and temperature detector (RTD) in the system to measure the T & P in the equipment. I suppose it is possible to have a shut off valve that will be told to close when the pressure reaches .03 psi. I like this idea for the industrial application. I think it may require a bit of software that may not be available in time for the test. If this is the case, I can probably use the liquid methods mentioned in earlier posts.
Does this seem plausible?
Thanks again
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
A pressure switch with an actuation point so light (.03psi) will probably not handle the inrush current of a solenoid. A low inrush coil relay may be called for in between. The switch action will not be a snap-action type for sure therefore low current capabilities only.
Be aware of the hysteresis of the pressure switch as this will result in a sloppy solenoid response.
You might also concider a solid state type pressure switch from Omega.
Regards
pennpoint
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
The more you learn, the less you are certain of.
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
My experience is that when we get into design situations like this we are trying to make somthing work that is not the best solution. Usually, in this situation I try to look outside the box and find a much different way to do it.
The more you learn, the less you are certain of.
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
The more you learn, the less you are certain of.
RE: Does such a relief valve exist?
RE: Does such a relief valve exist?
INWC = (12xPset)/(0.4335)
So for 0.03 psi set point
Required INWC = (0.03/0.4335)*12 = 0.83 inches of water.
For fluids other than water adjust required static liquid head in proportion to the liquid density used. Note this is independent of the type of gas used and the diameter of the pipe or tubing used. Normal liquid level in hte U-tube loop will be 1/2 that required, so that the liquid seal is broken at the required pressure.
One last caution, I still think you should be trying to find an entirely different way to do this, the height of liquid head needed is so small I would be concerned about equipment vibrations causing occasional releases.
The more you learn, the less you are certain of.
RE: Does such a relief valve exist?
I'd like to re-submit my suggestion for precision relief valves made by the following.
www.halkey-roberts.com
www.agmcontainer.com
These people I am sure can help you.
Regards
pennpoint
RE: Does such a relief valve exist?
Engineering Point #1: Amateurs built the Ark, Professionals built the Titanic - unknown
PSVEngineer