Scubapro Parts

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Location
The Woodlands, TX
I purchased a used Mark V Scubapro regulator for a pony bottle. I disassembled it and all is well with the seat and hardware on the first stage but would like to replace some of the o-rings. Can a person get kits to repair these or is it acceptable to use generic o-rings of the right size.
Thank you in advance...
Eric
 
Kits can be quite hard to come by and don't contain all the o-rings anyway, only those prescribed for annualy replacement. The good news is that all seem to be standard '2-' o-rings. At least, that is what I'm using on mine.
 
pop in "regulator kit" on ebay, there is usually someone selling scubapro kit on there
 
EPR (look at air-oil.com for a source) O-rings work just fine.

The only one to be careful with is the small piston HP O-ring. I've had no trouble with 70 duro EPR in there on the Mk10s up to 3500 psi or so (the max I actually use) but SP is currently using a harder compound - probably 80 or 90 duro, and rumor has it its a Urethane compound - and those are hard to get.

The 70 duro EPR O-rings in a Mk20 or 25 (with the plastic bushing system) WILL LEAK over 2500-3000 psi.

You want the "E-70" ones.

EPR is reasonably-compatable with high FO2s and doesn't suffer from the poor abrasion resistance of Viton. Its also a hell of a lot cheaper than Viton is.

The ONLY unfortunate thing with them is that they don't stock 90 duro EPRs. That sucks, because if they did they'd have everything in the O-ring department for scuba gear.

They can GET 90 duro EPR, but the minimum orders are at the several-hundred-piece level (per size!) for them.

I've bought and used a lot of their EPR O-rings and have been happy with them - they're quite reasonably priced and of excellent quality.

I've considered ordering up their minimum quantity of the -10s in 90 duro EPR, as that would likely last me for many years - we're talking like 600 pieces or so. -10s are used in a number of different places, with the most important (for this purpose anywhere) being the HP Piston ring.
 
Think Genesis said it all pretty well only thing is while I use EPDM aka EPR when they are not much more expensive than nitrile the difference between cheap EPDM and nitrile is probably not worth losing sleep over - I happily use nitrile 90s over EPDM 70s in spots where 90 is preferable, which in this case is the HP piston O-ring and maybe the LP, and don't think the difference is enough to worry very much about trying to find EPDM 90s.

Though like Genesis I have run many 70s in my MkVs and Xs when I didn't have 90s, without anything catastrophic happening.

Here some numbers that seem to be pretty good though not guaranteed.

Mk V 1st
swivel 012
piston HP 010
piston LP 022
yoke retainer 015
HP seat 013
seat retainer 015

109 (metal adjustable) 2nd
hose swivel end old style 010
hose swivel end Superflow 1x7 metric
orifice 010
balance chamber (balanced adjustable and later only) 1x1.8 metric
 
is that in a high FO2 application the exact place you DON'T want one is the HP piston O-ring - and that's the "special" in most piston 1sts.

That's a place where you could run into material compatability trouble more than anywhere else in the reg..... which is why I'd prefer EPR there if I could get it.
 
oxyhacker once bubbled...

109 (metal adjustable) 2nd
hose swivel end old style 010
hose swivel end Superflow 1x7 metric
orifice 010
balance chamber (balanced adjustable and later only) 1x1.8 metric

And the adjustment knob takes a 011. (SP #01-050-138, blue)
 
I believe were talking about more or less compatable (EPR-Nitrile)
and the buna breaking down faster but add in the diff from durometer and I believe durometer wins over material
 
Personally it doesn't bother me since I have no problem myself with using nitrile with elevated FO2s.

Also, it's my understanding, based on talks with several O-ring company reps, that there are different grades of EPDM. The cheaper import ones, which are the ones usually sold bulk by suppliers like Air-Oil are "oil filled", that is to say, made with extenders and fillers. These, I am told, compromise their O2 compatibility to the point where they are probably only a little better than nitrile. So if you are considering ordering a bunch or EPDM 90s, thinking they will be enough better than nitrile to make the effort worth it, you might want to check with your supplier on that point. The price I was quoted for "good" EPDMs, in the quantities I needed, BTW, was enough to put the idea out of my mind. But that was a while ago, and EPDM has been gaining popularity, so things may have changed.


Genesis once bubbled...
is that in a high FO2 application the exact place you DON'T want one is the HP piston O-ring - and that's the "special" in most piston 1sts.

That's a place where you could run into material compatability trouble more than anywhere else in the reg..... which is why I'd prefer EPR there if I could get it.
 
https://www.shearwater.com/products/perdix-ai/

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