IP creep questions

[underwater5]

I have an Atomic B2 reg and have 2 questions about IP.
First: I have read the threads about IP pressure should be about 135 +/- 10psi....if the IP is slightly higher 150-160psi does this alone indicate any problems?
Second: when talking about IP creep, what kind of pressure change indicates a problem? ie 5psi increase over 30 seconds or any increase over x amount of time?

Thanks, I have just got my first IP gauge and wanted to know more.

 

[LeadTurn_SD]

Disclaimer: I have not worked on Atomic regs.... so take this with a BIG grain of salt but;

1.) 150-160 seems "above spec" for almost all regs (except for Poseidon regs?). The 135 +/- 10 psi rule of thumb does seem to encompass a lot of regs as far as factory spec for IP goes.

2.) Allowable amount of "creep" varies by manufacturer. Some specify no creep after lockup, some allow a few pounds of creep over "x" amount of time after initial lockup, but then a stable IP. In either case what you are looking for is a good, stable lockup IP each time you purge; not 125, then 135, then 130.... etc., and not a gradual increase in IP over several minutes past the initial lockup.

I'm sure someone will chime in with the Atomic specs and tolerances soon.

Best wishes.

 

[mustang_5l]

Sounds a bit high for me... If it has just been serviced or new it could be as simple as dialing it out a bit to get it to the 135-140 range. However if after this it still climbs it should be sent back for servicing as there may be a problem with the HP seat.

 

[herman]

That is a bit high. A couple of things come to mind. Maybe not the most obvious but since the IP gauge is new, it is a possibility that it is out of calibration. Before doing anything else I would find another reg or air source of known pressure and check out the gauge or get a know good IP gauge and compair the reading on the same reg. If another regs reads high I would suspect the gauge instead of the reg. If the gauge checks out, then there is an issue with the reg. It may be in need of a simple adjustment or you have another reg issue. An IP of 160 is not the end of the world but if it were me, I would at least want to know why.
I don't get bent out of shape for a few PSI of creep if it happens in a few seconds and then locks up solid. Continous creep is a differnet matter and needs to be fixed. If your IP is at 160ish it is possible that your second stages are starting to gently freeflow and keeping it from rising any higher. This indicates you have a small HP leak and needs attention. Put your second stages and your LP inflator hose in a tank of water and see if you get any bubbles, even the slowest leak will show up in a minute or 2.

 

[halocline]

What Herman said about inaccurate IP gauges is true. You should try to check your reg with another IP gauge and see what it says, especially if it's 150, not 160. For an atomic reg, you have a balanced 2nd stage so it will be more tolerant of variance in IP. 5 psi creep over 30 seconds is not anything to get too worried about, but personally I'm not happy with any of my regs if they creep at all.

Atomic 1st stages are sort of an evolution of the MK25, which with the composite piston and a new seat is super stable, so I would expect the atomic to be the same.

 

[DA Aquamaster]

+2 on "check the IP gauge" before you make any solid assumptions. Someone serviced the regs and was supposed to check the IP, so their gauge may be high (resulting in a high IP) or your gauge may be reading high (giving a false indication fo high IP.

In a piston design where IP is set by shims, etc, a large change in IP is very unusual and it normally will not change at all pre and post services (if you put everything back in. With a reg using a spring adjustment of soem kind, an IP change is ocmmon and on some regs unavoidable,
so an IP gauge is essential to set the IP initially.

Normally, you will see an IP swing of 10-15psi, followed by an initial lock up and usually no more than 5 psi of creep over no more than 30 seconds. If you get more creep, you have an issue. Once the seat is broken in, you should get a very solid initial lock up with zero creep.

If I get a reg that is on the edge (5-10 psi of creep) after trying a couple new seats, I will often leave it pressurized a couple hours, and the recyle it and test it again. If that fails it is often an issue with the orifice itself.

 

[knotical]

fwiw, the Atomic maintenance procedures say the IP should be 125 – 145 "with little pressure creep out of the allowed range". Their shims adjust about 4-5 psi per shim, so if it is truly high (and stable), it should be pretty easy for a tech to fix.

 

[underwater5]

thanks to ALL for the info it is very helpfull!!
A little more info.... Herman, I think you are right I did find a slow leak in my HP hose for my SPG.
I plugged the HP port on the 1st stage and then submerged the first and second stage. my reading improved they are now IP of 150psi with a +5 creep over about 60 seconds. I left it connected for about 5 minutes and the creep increased to +10.
Of course I have not tried another gauge yet. but +10 creep over 5 minutes and then lock.

 

[DA Aquamaster]

regardless of the pressure, a 10 psi creep over 10 minutes befroe it finally locks up is a lot. It sounds like you have a slight leak past the Hp seat that eventually resolves after the IP gets high enough. A new seat would do wonders, if a new seat does not fix it, a new piston would be a good move.

 

[underwater5]

DA, thanks for the response. That is the kind of info I'm looking for. I'm not opposed at all to getting it serviced, I just like to know the in's and outs and all info in regards to performance.