Stab issue

[Jordan]

I rebuilt a Stab recently - really, just replaced the piston oring and reg seat base oring - and it doesn't regulate.

It airs up without any leaks but doesn't adjust - output is that of the tank regardless of where I put the adjustment screw.

Any ideas? Reg seat is in good shape and the brass holder has a fresh 010 seal and looks to be in good shape where the reg seat seals against.

[forumreader]

You likely have checked this, but first thing to do is make sure you are plumbed correctly, one of the ports is in, the other is out. If your plumbing is reversed, no regulation will occur but gas will pass through it at tank pressure with no adjustment available.

If that does not work, I like to pull the piston (and spring and screw and cap) and air it up. If the reg seat and the base oring are working, it will hold air and there will be no leaks. Then, you can add the piston and other parts and it should regulate up from there.

If that doesn't work, there are some other options, but getting these things knocked out will provide some good direction.

[Jordan]

You likely have checked this, but first thing to do is make sure you are plumbed correctly, one of the ports is in, the other is out. If your plumbing is reversed, no regulation will occur but gas will pass through it at tank pressure with no adjustment available.

If that does not work, I like to pull the piston (and spring and screw and cap) and air it up. If the reg seat and the base oring are working, it will hold air and there will be no leaks. Then, you can add the piston and other parts and it should regulate up from there.

If that doesn't work, there are some other options, but getting these things knocked out will provide some good direction.

I thought the same and double checked, but yes, I'm on the right port.

And I also did the air up minus the piston, spring, etc... it holds air, no leaks. Does not regulate, though.

[forumreader]

Good to know. At this point I would check for physical damage. I would look for any scoring where the piston rides and wear on the piston itself. I've seen regulators wear themselves to death by creating a shelf that the piston locks into so it can't move.

I'd then pull the valve assembly and inspect the base for any physical damage. The lip where the reg seat seals might have some imperfection that will allow a static seal, but might not seal consistently when you try to regulate. It's also worth checking to see if there is any physical damage to the base or pin to see if they are hanging up on anything - either each other or inside the bore where the pin needs to move back and forth.

Finally, do you have another reg seat to try? With other regulators that's the first thing to do, but these Palmer reg seats are dang near immortal. I asked Craig a couple of years ago how often he runs into a reg seat that needs replacement and he said it almost never happens. If you have another palmer reg on hand, it might be worth swapping in the reg seat.

That's all I've got for now, but there are always more things to try once more information comes to light!

[Grendel]

This might seem obvious but is a load or demand on the system? A Stabilizers output pressure can be raised on the gage in a closed non-demand situation but will not go down. There need to be a demand for the regulator to actually work beyond reaching equilibrium. This is why I built a reg. tester with a metered needle valve on the output so I can put a steady output demand when testing regulators.

[Jordan]

This might seem obvious but is a load or demand on the system? A Stabilizers output pressure can be raised on the gage in a closed non-demand situation but will not go down. There need to be a demand for the regulator to actually work beyond reaching equilibrium. This is why I built a reg. tester with a metered needle valve on the output so I can put a steady output demand when testing regulators.

As soon as I start adjusting the output via the bottom screw - from zero on the gauge - it immediately goes to tank pressure. It's either zero or 800psi.

[Jordan]

Good to know. At this point I would check for physical damage. I would look for any scoring where the piston rides and wear on the piston itself. I've seen regulators wear themselves to death by creating a shelf that the piston locks into so it can't move.

I'd then pull the valve assembly and inspect the base for any physical damage. The lip where the reg seat seals might have some imperfection that will allow a static seal, but might not seal consistently when you try to regulate. It's also worth checking to see if there is any physical damage to the base or pin to see if they are hanging up on anything - either each other or inside the bore where the pin needs to move back and forth.

Finally, do you have another reg seat to try? With other regulators that's the first thing to do, but these Palmer reg seats are dang near immortal. I asked Craig a couple of years ago how often he runs into a reg seat that needs replacement and he said it almost never happens. If you have another palmer reg on hand, it might be worth swapping in the reg seat.

That's all I've got for now, but there are always more things to try once more information comes to light!

Already performed a visual inspection - no defects noted.

I have a female Stab I could rob parts from, potentially.

[forumreader]

What a weird battle. It sounds like the valve is sound. The reg seat and oring are doing their job. When you put pressure on, the piston should be forced away from that valve and allow it to close. That's not happening. With the obvious stuff out of the way, it seems like a manufacturing defect or a poorly worn part would be the culprit.

That female stab could save the day (at least for diagnosing things). For many years the female stabilizer internals have been identical to a normal stabilizer. Parts swapping should be easy enough. Because it's the easiest, I'd start by swapping the piston. You could measure it and stuff, but I'd want to see if it works first. If it does work, I'd then get out the calipers and see where they are different. If the piston does nothing, I'd try swapping the valve assemblies. You could go part by part, reg seat, base nut, etc., but I'd just move the whole assembly right in and see what happens. And I'd check without the piston first, just to confirm that the swapped parts seal up before being put to task.

Let us know what you find!

[XEMON]

As soon as I start adjusting the output via the bottom screw - from zero on the gauge - it immediately goes to tank pressure. It's either zero or 800psi.

That is usually a dead give away about the valve sprint too week or the main spring too strong.

Dumb question: are you sure your gauge works?

[Jordan]

That is usually a dead give away about the valve sprint too week or the main spring too strong.

Dumb question: are you sure your gauge works?

100% sure the gauge works... just used it to set the Hyper2 I put on my Blazer to replace the inoperative Stab that was on there.

I don't have any substitute parts until I can locate my female Stab, so I can't swap in any known good parts at the moment.

[Jordan]

Found my female Stabilizer. Unfortunately it's an older unit that does not appear to share components... the piston does not fit the male Stab body, and the reg seat holder is different enough appearing that I don't plan taking it apart.

The male Stab was a bit rough externally anyways so I'm not heartbroken that it's out of commission, just disappointed I can't easily diagnose the problem.

[forumreader]

That's a bummer. That is an old female, I think only the real early ones loaded the valve components in from the tank side.

If you're super bored, you could try putting the reg seat from the female in to try. For reasons that can't be explained, air going past the reg seat when it shouldn't. Doesn't mean it's bad, but you have one to try if you want to check it out.

[Jordan]

That's a bummer. That is an old female, I think only the real early ones loaded the valve components in from the tank side.

If you're super bored, you could try putting the reg seat from the female in to try. For reasons that can't be explained, air going past the reg seat when it shouldn't. Doesn't mean it's bad, but you have one to try if you want to check it out.

I'm pretty over it. 😏

I'm not a massive fan of Stabs, just wanted to keep one on my Blazer mostly to stay with the theme. The Hyper2 I put on is doing a great job though, so I'm going to leave it, and the male Stab will go in the scavenge pile for when I need parts.

[Jordan]

Update:

I was putting an order in at PPS anyways so I bought a Stab rebuild kit and replaced the piston oring, reg seat, and seat oring. It now regulates correctly so the Stab is back on the Blazer, as it should be, and I'm happy to free up another reg to use on something else.

Moral of the story - spend $7 on a rebuild kit, it's worth it. 🙂