pop off valve pilot

[Quark]

i've seen multiple guns, some even full auto, piloted by a pop off valve. I don't understand how the the system works (especially how the pop off valve gets reseated) or even really a pop off valve, i haven't experimented with one. If anyone could post the secret, i'd appreciate it
thx

[thespeedycicada]

a pop up valve is just a normal valve that is rated to a specific pressure it will not open unless this pressure is met/exeeded or when you pull it open manually.Are you wondering how a piston valve works or just the pop up thats used to pilot it?

[BigJon]

The way that they reseat is by a spring. When enough pressure has been released, the spring simply justs closes it.

[Quark]

i've build three piston guns, one of which is on the forums
thx for the reply, i think that i get how they work