Keep blowing DIN regulator O-ring

[tstormdiver]

My Primary Din Regulator's O-ring keeps blowing out. It is a Subapro MK25/ S600 It is the O-ring that seats against the back of the cylinder valve. My double cylinder valves are 300 bar with an isolator manifold.This O-ring has popped out of it's place 3 times in the last year or so. It has never happened during a dive (thank goodness), but has happened twice during equipment set- up & recently while donning my cylinders in the water. To the best of my knowledge, I'm tightening it enough,.... or at least until I am unable turn it any more. The O-ring is the correct size (I believe),as the last time it happened I took the O-ring out of a brand new DIN regulator & used that. Anyone have anything similar happen? Know of the cause? Thank you.

 

[cool_hardware52]

My Primary Din Regulator's O-ring keeps blowing out. It is a Subapro MK25/ S600 It is the O-ring that seats against the back of the cylinder valve. My double cylinder valves are 300 bar with an isolator manifold.This O-ring has popped out of it's place 3 times in the last year or so. It has never happened during a dive (thank goodness), but has happened twice during equipment set- up & recently while donning my cylinders in the water. To the best of my knowledge, I'm tightening it enough,.... or at least until I am unable turn it any more. The O-ring is the correct size (I believe),as the last time it happened I took the O-ring out of a brand new DIN regulator & used that. Anyone have anything similar happen? Know of the cause? Thank you.

Scubapro in ther infinite wisdom uses a slightly smaller din oring than most of the rest of the industry.

Forgive me I'm not at my shop right now and don't have my references handy for a size, but if you ask for a "din oring" you very likely will get the wrong one for a SP reg.

Tobin

 

[scubafanatic]

.....I don't dive Scubapros, but do dive a pair of DIN Atomics, and my Atomics also use a 'rare' sized DIN O-ring in that application (size 111) while most DIN regs use (size 112).

 

[Chugwhump]

This is a wild shot in the dark,
but you may have come into some o rings that are the wrong size, essentially labelled and packaged incorrectly.
I got into that mess several years ago.
I mixed old with new and I ended tossing a boxful of them away to just start over.
Just a wild possibility.

 

[carrielsal]

What do you mean by "blowing"? Are they tearing? I have found that is I have not completely depressurized my regulators before I take my first stages off, the O ring will pop out.

Carrie

 

[tstormdiver]

By "blowing", I am saying the O-ring comes unseated from its groove in the regulator, causing that terribly loud hiss that all divers hate to hear. Only once has the O-ring been ruined to the point it could not be reseated & reused. Last night, when it happened I had the regulator fully pressurized. I was getting ready to practice in a pool. I was donning my cylinders, BP/W in the water. After it blew, I shut down that post (valve), depressurized the regulator. When I removed the regulator, the O-ring was just sitting there inside the valve, not in the proper groove of the regulator. I replaced the O-ring back into the regulator (it was fine), pressurized & depressurized the regulator several times & it did fine. I also dove with it today & it did fine. It seems to happen randomly. It seems to only happen to my primary & so far, has not happened to the secondary regulator, not sure why (not that I want it to happen to that one too).

 

[tstormdiver]

Scubapro in ther infinite wisdom uses a slightly smaller din oring than most of the rest of the industry.

Forgive me I'm not at my shop right now and don't have my references handy for a size, but if you ask for a "din oring" you very likely will get the wrong one for a SP reg.

Tobin

The last O-ring I put into it was off another, brand new MK25/S600 DIN regulator I have. If that O-ring is the wrong size, then it was done by Scubapro themselves.

 

[liuk3]

I had same problem. Replaced it with a new o ring of proper size. No more problem.

 

[halocline]

My MK10s are definitely 112. One of those is the later style DIN connector. Try getting some new polyurethane 90 duro 112 o-rings and see how that works. If it doesn't, I would suspect there's something mis-machined in the DIN connector or the valve. It doesn't take much clearance to have an o-ring pop out at 3000 PSI.

 

[tstormdiver]

Thanks all. So it is sounding like I may have the wrong sized O-ring that was installed by the manufacturer,.... or as was suggested, maybe a slight machining problem. Next time I'm at the LDS, I'll have them give me a couple O-rings of the slightly larger size recommended & see what happens.