Regulator Pistons Question

[Smokee_2_7]

Ok, Im getting a bit confused on regulator pistons. I understand that every now and then you might encounter a bad one that bleeds off too soon - -- - especially with lvl 10. I also can understand that the piston might wear out after a couple years. (should it though?)

What I don't understand is why 4 out of the past 6 level 10 installations Ive done have ended up needing new regulator pistons- - - not to mention MANY other people on AO experiencing the same thing. Both of my retromags needed new pistons after lvl 10 was installed. One of my more recent customers had to have the same. Here's the kicker- - - one of my teamates had me get an x-valve in for him last week. I install it and fine tune the level 10 settings- - guess what? I can't get it to shoot over 250 with the cut spring without loosing all my air out the back. after checking ALL o-rings and oiling everything up, still the same problem. So, not beliving what Im seeing take the reg piston out of one my retromags (which functions flawlessly) and pop it in the brand new x-valve. Well, i was right- - - now the gun works beautifully. AGD is exchanging the piston for no charge (as they should) except for the costs of faster shipping because we need this by wednesday!!! (Mardi gras open this weekend).


So, now that I've vented (no bad reg. piston pun intended) Im wondering WHY do SO MANY of these reg. pistons vent too soon? EVEN in the new ones? An o-ring I can understand, but a piston is a bit more expensive- - - otherwise I would keep about 4 of the things on hand for when someone needed one.

What makes a piston tick? HOW do they work? and finally, When AGD tests the valves, (with lvl 10) why do they only check the smallest spring at a lower velocity? It may work fine at 250fps with the short spring, but we'll be chopping paint if we crank it up to 290 with the short spring in there. . . .




Any info/ insight is greatly appreciated.


Carl

[ghideon]

I know in some cases (older Mags) the regulator piston can't deal with the higher pressures. I just slapped a new one in my EMag trying to get it to chrono at 280 without venting out the back on a medium spring/LVL 10 set up. I somehow wrecked it, and had to go back to the old reg piston which works (albeit only on the shortest spring).

Anyone with some more know-how answer this? I'm curious, too.

[Tunaman]

The reg piston is a safety device designed to blow out when the pressure gets to a certain level. This is to protect YOU. I believe TK has addressed this issue, and most new ones should be fine from now on. On the issue of testing, AGD does not test the new valves. They are assembled...and shipped. Hope this helps

[BlackVCG]

This is how the AIR valve piston is set up. The RT piston is the same way only it uses a cap in replacement of the large set screw.

I don't know why you're having such bad problems with them. I don't know why AGD isn't cranking them up well beyond the point that they'd start leaking at 300fps with the long spring. Maybe there was a bad batch or something.

Just keep calling AGD and telling them that their new pistons aren't working. Hopefully that will get it through to them that they have a bad batch of pistons and need to test them before them send them out.

[Smokee_2_7]

Thanks for the information, guys.

Does anyone know at what pressure the newer pistons are supposed to vent at? If I remember correctly, the actual operating pressure of the gun (pre-lvl 10) was somewhere in the 450psi range (at approx 28ofps). If that was the case, it would make sense for the piston to vent off pressure in the 520ish range to disable the marker from shooting extremely hot. Obviously, the operating pressure of the design has been raised with the introduction of the lvl 10 design. Dose anyone have the new number? (assuming cut spring at about 280fps?) How about an approximate number for operation with the long spring at 300? It would stand to reason that the reg. pistons should be manufactured to vent off pressure once it goes past the point where the gun could shoot in the neighborhood of 320-330 fps.


Finally, It is my understanding that reg. pistons may actually go bad over time. What causes this? I would think that overpressurization should not- - - you could think of the piston as a one way valve that opens when enough force is applied to it, and closes once that force is no longer great enough. If extreme overpressure could damage it (think about kicking a door open so hard that you break it) what caused the piston to not vent BEFORE the pressure got so high as to damage it?


Once again, thank you for the responses so far. THey have been very helpful.


Although I can understand that it is not feasable for AGD to pre-install and test EVERY reg.piston that they sell, I would think that some spot testing of piston batches could help curb the problem (although this may already be done). Perhaps you are right (BlackVCG), and they just got a bad batch of pistons. I am more inclined to believe that the reason i have had such crappy luck with them is because all but the new x-valve were older valves- -i.e. older pistons that may have been designed to vent at a lower pressure. It would make perfect sense to me that I was the one that wound up with the one defective piston out of 100,000.

The point where it becomes frustrating is when you have a gun down waiting for AGD to do a cross ship on a bad piston- - - and that gun has got to be top notch for the Mardi gras open this weekend.



Carl

[dave_p]

ok so if i can break the red locktite(heat gun do it??) and put a 1/4 turn on that nut(into the piston) this should increase the operating pressure of the piston? no?. cuz ill be damned if im layin out more cash to make something i paid good money for to work right.

[redlaser666]

It is technicaly un-safe to do so, but ive done it and it does work. just dont over do it. 1/8 of a turn should do it.