Preset Air "techy" Question

[Lucky]

I understand the whole HP/LP preset air thing but was wondering if any of the "techy's" on here can adjust the preset output, after all they must be factory set so unless they are sealed they should be able to be altered?
I have a HP PMI preset which should be set about 850psi and was wondering if it could be dropped to 600psi so it will better suit two guns and be more versatile for me.
Can it be done anyone?

 

[WingNut]

pretty sure it all to do with the spring stack inside the reg.

Do a google search on it. I'm sure you'll get leads of results.

 

[Speedyg4LS]

if you take your reg apart, you should find a stack of shims, removing some of these will lower your output, but it obviously needs to be checked before putting it on your marker

Speed's

 

[Tom Allen]

piece of cake, but start with the SHIMS rather than the SPRINGS. And you can double up a spring to make it slightly longer, but make sure you have a pressure gauge to check the output.
If you feel a bit unsure, i can do this for you.

 

[Lucky]

You say "piece of cake" Tom
I'm a hydraulic engineer by trade, so is it as simple as whipping out a couple of shims and then pumping the bottle back up to try the output each time, like i would with a hydraulic relief valve?
More shims & harder spring = more pressure
less shims & weaker spring = less pressure

 

[Tom Allen]

That's it.

 

[Lucky]

Thanks mate, your a gentleman.

I feel an "EXPLOSION" about to happen

 

[Tom Allen]

remember when adjusting the actual spring stack, try to keep the spring closest to the reg body concave.

( - reg body/bottle

 

[Tom Allen]

Originally posted by diablo66
Thanks mate, your a gentleman.

I feel an "EXPLOSION" about to happen

You should be used to that in your line of work...

 

[Lucky]

oh don't joke
When a 2'x1'x1' 6 way cast iron control valve fails at 5000psi, i'm afraid it's every man for himself and only the fit survive !
It clears a building quicker than a guinness fart