G250? Worth servicing?

[buddhasummer]

Ding ding, we have a winner, removed exhaust diaphragm, put tape over it and no leak, I won't try it on the other one, I'll assume that is the cause of its leak also.great tip, thank you. So given it is the exhaust valve, do I just ignore it, as I could never replicate the same intensity whilst diving of course. Also thank you for the tip re making sure air barrel is straight, worked like a charm.

 

[buddhasummer]

Onto the machine gun free flow:

I swapped out the "problem" G250 with one of my know functioning Apeks 2 stages and had the exact same violent machine gun free flow, which actually forces out at the same time out of the other 2nd stage. Just to be double sure I put the problem G250 onto my Apeks first stage and it functioned fine. Wanting to be triple sure I them put the functioning G250 onto the "problem" regs port on the MK25 but nothing happened, put the problem reg back onto its original port and no problem. This has perplexed me as all was pointing to the MK25 as being the problem and likely that particular LP port.

All I can think of is either something was in the reg causing the issue and it's now moved or been dislodged or it's stopped now because my tank is running low, at about 50 bar. Not sure.

Any suggestions? Thank you in advance.

 

[buddhasummer]

I'm guessing until this cause is identified diving these regs is a bad idea.

 

[rhwestfall]

My guess is that your 25 is in need of service.....

A $15 IP gauge that connects to the LPI inflator hose can reveal much...

If you are not getting stable IP (135-145), tuning and adjusting the second stage is essentially impossible.

50 BAR/700 psi - I tune at 3000/3500 and then check at 300-500.

 

[buddhasummer]

I have an ip gauge and it holds steady at about 130, the MK25 is brand new. What issue with the 1st stage could be causing this? And seeming out of one port only? It would certainly help explain why I'm having so much trouble tuning one of the regs...yeah, I started out with a full tank but trying to find the cause of this violent free flow ran the tank down pretty quickly. I always tune with a full tank.

 

[buddhasummer]

I should add "seems" to be holding steady, I haven't left it sitting for any great length of time to check. I'll hook it back up with the remaining 50 bar for a few hours or over night and see what happens, if it is creeping could it cause an issue if left unattended over night?

 

[rhwestfall]

If IP is drifting, it bull build, exceed the hold back ability of the spring and balance chamber/poppet, and then "burp" (free-flow). Likely nothing bad but a potentially empty tank... the design of the second is a "fail safe".

Even though new, that 25 may have an issue. An o-ring might have been bad or damaged on assembly allowing a leak, or there may be some lubrication issues. It might be "marginal" and thus appearing at high pressures, but not being seen at the low pressure you have now.... I'd be curious as to how IP reacts under some cycling and sitting for a longer period of time.

You have so many "moving targets" it's really hard. Get the tank filled, and start with the G250's on your other brand first (what is that IP?), tune them, and see what they do. From there, diagnose the 25 first stage, again, with a known functioning second stage. Only make one change at a time.

 

[buddhasummer]

Thanks Bob, will do as you suggest. It's crept 10 PSI in just under 40 mins.

Apeks, IIRC it sits at around 140 PSI...

 

[buddhasummer]

Just cycled the regs a few times, in dropped back to 130, within about 10 mins it was creeping on 140...looks like the 1st stage is the issue. This is the third piston reg I've had issues with from new, two SP and one Atomic. That's three for three. Think I'll fix it and flick it and go back to diaphragm regs, never had any issues with any diaphragm regs. Just bad luck I guess but it's putting me off them.

 

[rhwestfall]

10 isn't "bad", especially for a new seat. That is why they are cycled for a "break in", and then re-adjusted. I'd be real curious as to what happens with 3000/3500 psi on it.... It may not climb further with only 50 BAR. If it does, then you have some answers. With a breath or a purge (a couple successive), does it return quickly, or lock and then creep?