Mk25 Swivel O-ring

[Tekkie]

Hi,
I have a question about the o-ring in the swivel in the Mk25. I have herd that swivel regulator first stages have the chance of "blowing" because the o-ring bursts. Has anyone ever had this happen to them? I didn't see anything about swivel regulations on the DIR web site. Are there any big chances of this happening?

Thankz!
Tekkie

 

[metridium]

Happened to my Mk20 once on a solo dive...fortunately predive.

Now I dive H-valves or doubles, or with a trustworthy buddy.

 

[padiscubapro]

Never had a swil based reg fail during a dive.. I did have a tx50 1st stage fail predive drills with buddy.. It had a minor leak so it was swapped out..

 

[ElectricZombie]

Nope, never had one fail. Have 2 Mk25s and a Mk10 that also has a swivel O-rig...no problems on any of them. I think that the ones that do fail are caused when the tech does not use the proper torque when reassembling the reg.

 

[dmdalton]

Haven't had one fail in 40 years of diving. If regs are inspected and taken care of it is very unlikely. Could it happen? Yes. If it did it would likely be a small leak which hopefully you buddy would notice. Not a massive failure.

Dave D

 

[FredT]

Similar design hardware.

This was right at the first of the dive. Seems she caught her octo on the wire rail of a sailboat when doing a giant stride entry. It tore the swivel clear off the reg. We aborted the dive. I picked her swivel and seconds up off the sailboat deck. I put a new swivel on it from the "spares" box I carry, and she has used the reg for the last 20 years without another failure. The one that failed was the older "snap ring" turret assembly, but I don't think either design is supposed to stop and support a 100# diver after a 5' free fall.

BTW breaking a LP hose has nothing on ripping off a swivel for air loss rate.

FT

 

[oxyhacker]

Turret loss on old Scubapros seems is very rare, but still just about the only catastrophic failure mode on these bulletproof old regs. When it happens, its almost inevitably the result of a turret bolt that was badly overstressed during incompetent servicing.

I always inspect these carefully on any used SP 1sts I buy (and I got a half dozen MkVs and Xs around, all bought used) and similar regs, and replace them if there's any doubt - the bolt's cheap enough that its probably worth doing it routinely on any reg whose history is not known. However careful visual inspection will usually spot an abused one - it'll show "waisting" at the point of stress, where the diameter of the bolt is pulled in and the threads elongated.

FredT once bubbled...
Similar design hardware.

This wa right at the first of the dive. Seems she caught her octo on the wire rail of a sailboat when doing a giant stride entry. It tore the swivle clear off the reg.

 

[lucid]

I just bought a couple of mk25's a few weeks ago. Man what a mistake. I am gonna ebay em and go back to apeks. One of the things I checked into was the chance of this o-ring blowing. I kept hearing stuff like 'itll never happen', 'I have been diving them for umteen years and it hasnt happened', 'the o-ring is blah blah so its almost impossible for it to blow'. Well mine blew today. The regulator isnt 4 weeks old and has been in the water about 10 times. POS.

 

[ElectricZombie]

lucid:

What O-Ring went bad?

Where did you buy the regs?

 

[lucid]

Its the o-ring in the swivel. its black covered with lube and now bulging out. It was purchased at an authorized Scuba Pro Dive Store.