making grainger valve go to 30psi

[acannell]

got a typical grainger valve

want to be able to adjust it up to 30psi..right now seems like it maxes out at 20psi...

any ideas?

im thinking i could put some kind of spacer inside to put more pressure on the spring at a given screwed-in-depth

or a stronger spring, but it might be hard to find the right diameter and strength

or two gvalves in series..i BELIEVE that would double the activation pressure drop

[Screamin4banger]

no, 2 of them in series will not double up on the pressure, it will just get by the first and the second will see the same press as the first saw.

Find an old-school hardware store, not a home depot, but a true value or an ace. they should have bins with all kinds of little springs to choose from. find a couple with the same dimensions as the one you have and different firmness and go home and play....

or, you could go a whole different route.
get a solenoid valve that will hold the 30 psi and wire it into an adjustable pressure switch. I know you can get all that online and the press switches are easily adjustable (up to any press you can imagine) and since its electric(no messing around with a hot g-valve), once the switch sees the preset press, bam! and the solenoid opens

[Sittn86]

^Just make sure the switch is quick-release. Dempsey lists a NAPA part # on his site. I think there's a FAQ on this, with a PN for the spring at McMaster-Carr.

[Sittn86]

I just checked. There is a FAQ.......

[Gutfeeling]

You would be better off putting on a different wg can that starts at 20 psi and then cranking the MBC upto the desired pressures. I have a WG can from a holset that has part of the rod still attached to it if you're interested. Just weld/thread on a additional length rod to it and bam, 19 psi. I think 19 is the lowest setting for it.

[impuresoul2k3]

but if the MBC can't hold 30 psi then starting at 19 won't get him anywhere anyway

[turbokid]

Thats wheres the stiffer spring comes into play

[Gutfeeling]

Another thing you dont want to do is use a low pressure spring rate wg can and regulate high pressures before it. Reason is, it might blow the diaphragm inside the can from the very sudden high load of air. Cause the spring in the wg can couldn't put enough pressure up against it to allow a swift move rather let it just snap open the puck. So either way you go, you should use the min. spring rate that you want you boost set at.