MK10 Intermediate Pressure?

[mcgowman]

Anybody know what the intermediate pressure should be on a Scubapro MK10?

Was checking it earlier tonight and noticed it starts at 115PSI and after about 10 mins to creeps up to 125PSI and then stays steady.

Not sure if the tank pressure has any impact... the tank I'm using only has about 400PSI.

Thanks.

 

[Zung]

Nominal IP range is 125 to 145 PSI, the value to aim for is 135 PSI.

Your tank pressure is too low to be reliable. Some of my regs start to drop IP at around 350 PSI. However, this should not affect the stability of the IP. Get a refill and see what's up.

There're 2 main reasons why the IP creeps:

• HP seat worn, the reg is begging for a service, so service it.
• Piston knife edge damaged. 10 PSI is not a big deal, probably some light nicks or scratches. See the thread I started and polish them off. Or get a new piston for $30.

 

[tfsails]

If you can get to 125-145 psi IP and it only creeps 10 psi I wouldn't worry too much about it. Lots of regs creep that much and some creep more. It should lock up within specs, though. If it doesn't, get it serviced.

 

[Fishpie]

I like to set IP at 120 when matched with balanced 2nd's, and 135 with unbalanced 2nd's.

 

[halocline]

If you can get to 125-145 psi IP and it only creeps 10 psi I wouldn't worry too much about it. Lots of regs creep that much and some creep more. It should lock up within specs, though. If it doesn't, get it serviced.

I would not accept 10 PSI creep in a MK10. Maybe 5, but when mine get to that point I get ready to rebuild them. With a nice polished piston shaft (micromesh) and a new seat, mine lock up pretty well. Not as well as my MK5s, but perfectly acceptable. In fact, I've been waiting for one of my MK10s to start creeping so I can justify pulling it apart to pack the ambient chamber, having finally found a pair of SPEC boots.

I also think 120 is a bit low for the MK10; I'm sure it would still work fine with a good balanced 2nd, but it is lower than SP spec. If I rebuilt one of mine and it locked up great at 120 I'd probably leave it, but if it was a friend's I'd put another shim in.