Auto Chamber Loading With Adjustable PSI

[Spudnik Tweaker]

Auto Chamber Loading With Adjustable PSI: I need a way to accomplish this.

I am looking for some type of pop-off valve; one that would work in a way whereas you could actually adjust the PSI level that actuates the safety release.

Basically I want to automate the triggering for my system. Rather than other automatic designs that get multiple shots from a same single chamber charge, I want automatic shots with a new full chamber recharges before every shot -- this way all of the shots have identical velocites. I want to avoid the other typical designs that have weaker and weaker shots on every following shot.

For example, say I want the chamber to be set so that when it reaches 80 PSI, a relief-type valve attached within a piston valve is adjusted so that it will automatically open up when the pressure reaches the target level, exhausting the pilot air. That in turn would activate the opening of a piston valve.

Can air compressor regulators do this, and if so then how would I rig this system? Thanks.

[Hotwired]

It's been thought of before for full auto and what you need are: Relief Valves

[jackssmirkingrevenge]

here ya go

[Spudnik Tweaker]

It's been thought of before for full auto and what you need are: Relief Valves

Thanks ... but I am very well aware that relief valves exist. Those don't do the job that I need though, as in my OP I wrote that I needed the PSI to be "adjustable" (variable PSI setting). I need to be able to change the PSI level for different applications.

Thanks anyways.

[jackssmirkingrevenge]

not cheap but take a look here and here. With a bit of ingenuity you could easily make your own.

[Spudnik Tweaker]

not cheap but take a look here and here. With a bit of ingenuity you could easily make your own.

You are the man Jack!

I'm not going to buy that valve, "but" at least I now have a reference for my concept.

I may design my own. But, something in the back of my mind tells me that you could modify a regulator to accomplish this "adjustable PSI relief".

Gotta lot of work ahead of me.

[Hubb]

...something in the back of my mind tells me that you could modify a regulator to accomplish this "adjustable PSI relief"...

That's what I was thinking. Most regulators have an adjustments, which is usually some type of screw. That screw could be replaced with a thumb screw for quick adjustments.

A regulator would also allow your chamber to automatically refill.

[jimmy101]

Any old generic regulator should work, check near the compressors at your local hardware store. You should be able to get a 10~120 PSIG reg for maybe $20. Here's one for $15.

Obviously, you don't need the filtering capability of this one but it was the first one I found with google.

A safety relief valve probably wont work. Usually, that type of valve opens predictably at a set pressure but they will stay open until the pressure drops well below the set point. They really aren't designed to act as a regulator and won't do a very good job.

[Spudnik Tweaker]

...something in the back of my mind tells me that you could modify a regulator to accomplish this "adjustable PSI relief"...

That's what I was thinking. Most regulators have an adjustments, which is usually some type of screw. That screw could be replaced with a thumb screw for quick adjustments.

A regulator would also allow your chamber to automatically refill.

Yeah ... sweetness!

[Spudnik Tweaker]

A safety relief valve probably wont work. Usually, that type of valve opens predictably at a set pressure but they will stay open until the pressure drops well below the set point. They really aren't designed to act as a regulator and won't do a very good job.

Hmmm ... I've seen some that reclose when pressure is reduce to say 5-10% for instance, and in that case for example, in my intended setup/design, "precious" air loss shouldn't be an issue.

You see, I am working on a piston valve that reseals swiftly, therefore it would be the piston's (the piston valve within the main pressure chamber of the system) dynamic movement that controls the pilot-exhaust cutoff time. And in any case, I am also working on recycling the pilot exhaust air, therefore much of it should not go to waste.

So the thing I'm really in need for is a PSI-adjustable,automatic pilot relief.

I don't really care what is used as the auto relief (what ever type of valve,\modified valves etc.). I just need it to:

1) Have an adjustable PSI relief/exhaust

and

2) Automatically activate/release the pilot air when the "set" PSI is reached

[jimmy101]

Spudnik then what you want is a generic small, cheap, regulator. Pick one up at the local hardware store for $10~$20.

[Spudnik Tweaker]

Spudnik then what you want is a generic small, cheap, regulator. Pick one up at the local hardware store for $10~$20.

Cool .. Okay, so a regulator would also automatically perform the "venting" task, when the main piston valve chamber reaches the set PSI?

All I know is that a regulator controls the flow pressure coming out of an air compressor's main tank.

Please explain, as I do not fully understand how I could rig the reg. into my system in order to accomplish the goal I had in mind. Thanks.

[Hubb]

The regulator puts only a set amount of air into the chamber. If the chamber is exhausted, the regulator will open and remain open until the chamber reaches the preset PSI on the regulator.

[Spudnik Tweaker]

The regulator puts only a set amount of air into the chamber. If the chamber is exhausted, the regulator will open and remain open until the chamber reaches the preset PSI on the regulator.

Thanks. So looks like I will have to invest in an adjustable relief valve. I will rig my compressor up to the main chamber for constant air charge.

[iknowmy3tables]

you can also use a pressure switch attached to the sprinkler valve
I don't like that relief valve setup on QEV and piston valve, I think its best for sprinkler valves or spring loaded valves that can be filled from the chammber