[redbaron]

Does anyone know of a device that would let gas escape as it hits a certain pressure? I have an apparatus that is a glass container, which has a constant stream of gas going in, which causes a reaction at about 300psi. I need the reacted gas to be released though, so is there a device would let gas stream out so the pressure in the container remains around 300psi? If not, does anyone have any reccomendations?

[Dude]

There are devices known as "pressure relief valves", however, the applications I have use them as safety devices (ie only used in an emergency).  I suppose a high quality device would maintain a constant P.

[redbaron]

Thanks, I will look into that. If those are only used for emergencies, what do companies use when they are in a situation similar to mine, where they need a constant pressure, but also need a constant flow in the reactor?

[Donaldson Tan]

LOL.

Pressure relief valves are used in a variety of application. The operational principle is that the valve prevents the internal pressure of the container/system from exceeding the threshold of the valve.

Ever consider providing an external cooling duty?

How about a simple gas pressure regulator?

[mbeychok]

Redbaron"

Do you really mean a glass container? Operating at 300 psi? Wow! Hard to believe.  Did you perhaps mean a glass-lined container? How large is your reactor (i.e., dimensions) ?

In any event, all you need is an ordinary pressure control valve (used in what is called a "back-pressure controller" configuration) installed on the reactor gas outlet line.  Any oil refinery or petrochemical plant has hundreds of back-pressure controllers.  When installed, the standard procedure is to install shut-off block valves before and after the pressure controller as well as a bypass line (with a shut-off block valve) that can bypass the flow around the control valve when it requires removal for maintenance or replacement for any reason. Here are some of the widely used manufacturers: www.fisher.com and www.masoneilan.com

A pressure relief valve is definitely the wrong thing to use as a continuously operating pressure controller.  They are meant to be used only for emergencies. They are not meant to be continually opening and closing.

If your reactor is truly a glass vessel, is it in a laboratory in some sort of isolation room in case it overpressures and shatters?  If it is a glass-lined vessel on a industrial plant scale, then it should also have an emergency pressure relief valve installed to prevent it being damaged if it is overpressured.

[bwgpolymer]

You can devise a sensitive pressure valve by youself. When the pressure exceed 300psi,  a gas is released automatically.