Why does this keep pushing out reg seats

[Brandon]

I posted a little bit ago about this regulator, I was pointed towards replacing the reg seat. I did that, reassembled the reg and it’ll hold pressure stead for about 2 min then it will spike. I disassembled it and inspected the reg seat and it’s pushed out of that steam part that it’s inset into ( forgive me I don’t know the proper terminology). What’s causing this and how can I fix it for good?
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[Ecapnation]

How old is the reg and is that the original reg seat?

[Brandon]

No the OG reg seat was shredded, I got the reg off eBay for a good price.

[BrickHaus]

You adjusting it under pressure?

[Brandon]

Wouldn’t you adjust it under pressure to get desired velocity on an ego ? What’s the difference?

[BrickHaus]

It's just a design flaw in the regulators that was brought up by other members. With air applied you have the piston pressing against the seat from the pressure applied.

It's far from ideal, but since the discussion, I'll shut air off to my reg, make a calculated adjustment. Air it back up, and shoot.

[caylegeorge]

Never seen a problem adjusting these regs under pressure. its how they were designed, even if not completely ideal it is a fairly widely used setup.

[TinCan1154]

Did you read my mind!? Holy sh**. I’ve burnt up 3 LP gauges because I tried to “upgrade” my reg seat to urethane. Same Ego 09 era reg.

Contacted George who I bought them from and he sent me a few extras in different materials and an elusive “oversized” alternative. He says, some brass caps are a little larger than others. Installed the oversized one the other day and have put a few hoppers through the marker without fail. The others would blow out in under 50 shots and then smoke my LP gauge.

Also, check the poppet seal that’s under that brass cap, if it doesn’t seal, you’ll get all the tank pressure and would also likely cause that seat to fail.

[TinCan1154]

If it’s smoked, there is no replacing it. Gotta buy new piston assembly.

[Brandon]

I removed the brass piece and the small, item that was under it (not sure what its called) was broken in two pieces. I'll order another one or two. Thanks for the help!!

[latches109]

Tincan - for testing - use a tank regulator with an output pressure set below your gauge max, this will save your gauges.

[TinCan1154]

You can also order a whole new piston for these… but could be NOS from ANS, but that will likely negate your savings from the eBay deal.

[caylegeorge]

Heyo,

I'm the guy that sells the reg seats on ebay (mpqtmagnum).

Happy to answer and questions about rebuilding these regs, I've done a ton, and usually its pretty straight forward.

Definitely want all the other seals in the reg to be in good order, and a full rebuild is usually prudent. Also, if you can, being able to pressure-test the reg off the gun is ideal.

I would definitely try and fix the rubber seal under the brass cap first.

That little piece under the brass cap is the check valve. Basically what it does is when you turn the air off to your marker, it lets all the air completely bleed from your marker. With older EGOs without that check valve, (and subsequently no hole in the middle of the reg seat), there would still be a few shots of air in the marker even with the tank removed.

So, on one side of that little rubber piece is the tank input pressure (high) and on the other side there is the reg output pressure (low). The high cant get to the low because of the rubber check valve stopper. And the low can't mix with the high because it is not strong enough to push back and open the check valve in reverse.

When the tank is removed, the High pressure goes away, and now the air in the marker (low) is strong enough to push back on the check valve and then can open the check valve in reverse and the air in the gun bleeds out through the asa.

Essentially, the check valve is not necessary as long as you are ok with your marker having a little air in it after you remove the tank (and then you just shoot a few times to drain it like you would with an older ego).

So, if you cant get a replacement rubber seal a solution is to eliminate the check valve. You could try any number of ways. You could fill the little cavity where that rubber stopper was with some epoxy, or even some hot glue. Additionally you could put a completely flat regulator seat in the piston, with no hole in the middle in addition to plugging up the check valve. If it were me, I think id try the hot glue route, screw the brass cap down over it, and see how it goes. Ymmv of course

[Brandon]

Thanks for the message on Ebay! I was away all weekend so I didn't get a chance to get out the hot glue gun but I'm going to give it a shot.

[TinCan1154]

Thanks for that explanation, George. You had helped me through eBay and sent me the extra seals of varying sizes and materials which was much appreciated.

I thought you’d solved it with the oversized urethane seat, but yesterday it failed on me. Going to try the different material options. All seals on this reg have been replaced
and also has a new piston assembly from ANS. May just be a bad reg, I don’t know.

[caylegeorge]

Heya sorry to hear that's the case. Let me know how it goes - I'm happy to help ya any way I can.

[PlawB]

Heyo,

I'm the guy that sells the reg seats on ebay (mpqtmagnum).

Happy to answer and questions about rebuilding these regs, I've done a ton, and usually its pretty straight forward.

Definitely want all the other seals in the reg to be in good order, and a full rebuild is usually prudent. Also, if you can, being able to pressure-test the reg off the gun is ideal.

I would definitely try and fix the rubber seal under the brass cap first.

That little piece under the brass cap is the check valve. Basically what it does is when you turn the air off to your marker, it lets all the air completely bleed from your marker. With older EGOs without that check valve, (and subsequently no hole in the middle of the reg seat), there would still be a few shots of air in the marker even with the tank removed.

So, on one side of that little rubber piece is the tank input pressure (high) and on the other side there is the reg output pressure (low). The high cant get to the low because of the rubber check valve stopper. And the low can't mix with the high because it is not strong enough to push back and open the check valve in reverse.

When the tank is removed, the High pressure goes away, and now the air in the marker (low) is strong enough to push back on the check valve and then can open the check valve in reverse and the air in the gun bleeds out through the asa.

Essentially, the check valve is not necessary as long as you are ok with your marker having a little air in it after you remove the tank (and then you just shoot a few times to drain it like you would with an older ego).

So, if you cant get a replacement rubber seal a solution is to eliminate the check valve. You could try any number of ways. You could fill the little cavity where that rubber stopper was with some epoxy, or even some hot glue. Additionally you could put a completely flat regulator seat in the piston, with no hole in the middle in addition to plugging up the check valve. If it were me, I think id try the hot glue route, screw the brass cap down over it, and see how it goes. Ymmv of course

I just want to say that I treasure people like you who sell reg seats on ebay. Ya'll have brought new life to some of our favorite markers.

[Brandon]

Just an update, as per caylegeorge suggestion I attempted to delete the check valve and replace it with glue to seal up that space. It was unsuccessful... I ended up getting an entire new from ANS on ebay (15 dollars )

[TinCan1154]

Let us know if you experience any creep with the new piston. I still don’t have mine dialed in.

Update: Just got a new piston. No creep and good recharge. Solved for now.

[TinCan1154]

Back to the old. This thing has failed more times than any reg I’ve owned. I don’t get it. At this point I’ve gone through all the extra reg seats I had as well as 2 “new” pistons.

[Brandon]

I put the new piston in mine, and just did a " bench test " it held air with no creep for a few hours. Haven't used it on a marker though.

[TinCan1154]

I put a case or 2 through with the new piston before it failed… Probably going back to CP.