Shelf-Life of regulator rebuild kits

[Rusty Shackleford]

I have a bunch of Scubapro service kits purchased circa 1999-2001 when I was a tech for a local shop.

What is the shelf-life on the O-Rings in these kits and what are the Scubapro O-Rings made of?

 

[bl6394]

The composition of the o-rings was described as proprietary and not disclosed in the Scubapro repair class I took in 2015. Warnings were given not to substitute o-rings not in the kit. A mix of Buna-N (Nitrile), EPDM, Viton, and proprietary seems probable.

Our shop tech's experience is that a shelf life of 5 or 10 years for the Scupabro kits is reasonable. But no more than 10. He found the low pressure o-rings (probably nitrile) get dry rot and just pull apart. He said a shelf life of 5 years was the number passed around at tech classes he's attended.

That lines up pretty well with the recommendations from the SAE: http://www.sealanddesign.com/Public/files/O-Ring-Shelf-Life.pdf Nitrile (Buna-N) have a nominal 8-10 year shelf life. How you store them probably has an effect as well. My tech's were stored in an airtight, climate controlled environment. If they were out in a shed - or hanging on a shelf exposed to sunlight - your mileage may vary.

Myself - I wouldn't use 15 or 16 year old service kits - except on my pool regulator. I love practicing CESA's.

 

[Jack Hammer]

Not Scuba Pro specific, I would add it shelf life depends on how/where the kit was stored. I always pull and rotate through my fingers then squeeze O-rings to make sure they haven't hardened or cracked. I've found a few bad ones that way.

 

[redacted]

If the o-ring feels right, I would have no problem using it. I still have the old colored scubapro o-rings in some of my regs. But the smaller red one like on an orifice do seem to have a problem with hardening and cracking. But the failure mode is not catastrophic, thankfully.

 

[NotSure]

I think it was in the 80's when Scubapro stopped using polyurethane o-rings but if your kits have any translucent yellow o-rings those are almost never usable.

 

[Rusty Shackleford]

Mine are all black. Post-colored material. Some have a white stripe on them IIRC.

 

[Rusty Shackleford]

Not Scuba Pro specific, I would add it shelf life depends on how/where the kit was stored. I always pull and rotate through my fingers then squeeze O-rings to make sure they haven't hardened or cracked. I've found a few bad ones that way.

I am beginning to think it would be best long-term wise to seal new rebuild kits with a vacuum sealer and then stick them in a freezer chest.

 

[DA Aquamaster]

Scubapro suggested a 3 year shelf life on the old colored polyurethane o-rings - but that no doubt assumed worst case (high heat and direct sunlight) storage conditions. As AWAP noted the red ones got crispy fairly soon. The purple o-rings didn't fare much better, but on rare occasions I'll see an old reg come in with blue o-rings that are still going strong (but they get replaced anyway). I suspect that more red dye equalled shorter shelf life.

Scubapro has been using EPDM o-rings for at least the last decade in their regular service kits, so I disagree with the post above suggesting they are a mix of Nitrile rubber, EPDM and Viton. I won't swear to what they use in their green o-ring "O2" service kits. It's probably Viton, but some of them look a little different than the normal Viton o-rings you see.

Scubapro has lately developed a habit of trying to make their stuff sound mysterious and proprietary as a marketing tool. For example in the SP course I took last year, Renee was insisting their plastic second stage case be called "technopolymer" and he referred to their Acetyl parts as an "Acetyl technopolymer".

I suppose the same thing could be happening with the o-ring terminology as plain old EPDM might not be viewed as special enough.

 

[DA Aquamaster]

I don't think sticking them in a freezer is a good idea. Room temperature is fine, and if anything keeping them away rom direct sunlight is a good idea.

My spares kit lives in a black dry bag, so it stays dry and protects the parts and o-rings from light. I keep it in the house where it has a stable temp, rather than storing it in the garage, where it would suffer from heat and cold.

 

[Rusty Shackleford]

All my kits have black O-Rings. I took my Scubapro service tech class from Bob Outlaw at Bluetone/Blue Dolphin in 99.

I would assume that means they are EDPM. They have been stored in the dark, away from UV. What would the shelf life of EDPM be?

Is there any way I can test the O-Rings? Examine them under a magnifying glass, stretch or roll them with my fingers?

I had most of my old Scubapro regs rebuilt and brought up to date (I have mainly been diving my Atomic the past several years and got stale on my servicing) just a few weeks ago by Ronnie Outlaw at Bluetone/Blue Dolphin.

I have a bunch of the older kits but Ronnie also said the newer kits include more O-rings, I assume static ones for the port plugs and change more parts. He made sure everything was brought up to current specifications.

I have a girlfriend now who is getting into diving and am getting my old regs in good working order to help support her and just because, they are still perfectly good and serviceable pieces of equipment.

I hate to waste the old kits on the one hand, the HP seats in the 1st stages should be fine. Ronnie said the plastic parts should be good for a long time and I can always get replacement O-Rings from Grainger or McMaster-Carr if I have a size list or am so inclined.