Scubapro O-ring Sizes

[Couv]

Nice work Doc,

Much more accurate than my pictures below. SP does indeed use EPDM for that application. I've attached a helpful chart showing the standard sizes and materials. The thanks goes out to Zung for all the hard work on this table. Additionally, for my own regulators, I have had success with Viton o-rings from McMaster McMaster-Carr
The i.d. for these o-rings is 2.0 mm not 2.2mm (less than 0.008 in) and remember, the true i.d. of an o-ring is determined after it's installed. The FKM (Viton) seal in the link above is very reasonably priced at about $2.50 for a pack of 25.

 

[rsingler]

Fantastic, couv! Very nice work on that table.
Yes, I use McMaster-Carr for 90% of my o-rings. Did I miss that one? Do you have a PN for the equivalent to that Precision 2.2 x 1 mm that I photo'ed?
Is there an EPDM one?

 

[Couv]

Fantastic, couv! Very nice work on that table.

The thanks goes out to an A$$hole With A Penison & Zung for all the hard work on this table.
The SP part number is the same as you have: 01-050-360
The McMaster link above should take you to their part number 9263K283 for a Viton 2.0x1.0mm o-ring.
Here is a link to a EPDM 2.0 i.d. X 1.0mm c.s. (McMaster number 1289n301) $4.40 for a pack of 50
McMaster-Carr

Sorry no exact match, but again you are looking at less than 8 thousands of an inch difference. (0.008 in.)

Edit: the Parker number for a 2.2mm i.d. X 1.0mm o-ring is 5-101

 

[rsingler]

Well, I'm a little OCD over that lightweight poppet.
I'll stick with 2.2mm, (and the separate shipping charge, lol).
Thanks for checking, couv!

 

[Couv]

Well, I'm a little OCD over that lightweight poppet.
I'll stick with 2.2mm, (and the separate shipping charge, lol).
Thanks for checking, couv!

I guess I'll have to send the good doctor a few so he can compare under his microscope.

 

[rsingler]

Then you'll know why you always have those LITTLE TEENY bubbles coming out of your mouthpiece.

You don't have to measure them, couv. The bubbles are 0.1mm diameter.

 

[Fibonacci]

Thanks for some really useful info... are there any guides for other SP seals?
I did a quick search but nothing I can see for BC seals...

I'm restoring an older Scubapro BC in good condition (pre welded connector) which has a threaded collar at the hose elbow sealed with an o-ring. The o-ring has taken a set and there is a small but annoying leak from the elbow so I'd like to replace it.
The recess in the BC elbow is 29.25mm dia x 3.90mm deep, the inner collar that the inside of the o-ring seals against is 23.2mm dia.
The old o-ring (with a set) measures OD 29.90mm x ID 23.20mm x 3.65mm
Just wondering if Scubapro used Imperial or Metric o-rings, or if there is a service kit available?
I'm thinking an ID 22mm x 3.5mm will fit allowing for a bit of compression when seating into the recess...?

 

[Couv]

What is the model of BC? I can try digging around in my files to see if I can locate that p/n and seal information. In the meantime, this is where a trip to the hardware store to buy cheap seals just to find the correct size is often helpful. I'm guessing the seal you need is a -212 but I would buy a few seals larger and smaller just in case. Once you've determined the correct size-then order the more expensive seal so in 10-15 years from now the cheap ones fail you'll have it.

 

[Fibonacci]

What is the model of BC? I can try digging around in my files to see if I can locate that p/n and seal information./QUOTE]

Thanks Couv!

I had a good look and there's no model info on it at all, just a generic Scubapro jacket BC with an older threaded elbow pillar and clamp washer, not ultrasonically welded like the modern ones.

The flanged clamp washer that fits around the threaded pillar and faces the BC jacket fabric has a recess for a flat washer (missing) so it seems the connection required both an o-ring at the elbow joint and a flat washer to seal correctly... no wonder it was leaking!

I'll have a look for a -212 Imperial o-ring which appears to be a ID 7/8" x 1/8" and a Metric ID 22 x 3.5mm and see how I go.

Out of interest, did Scubapro design in Metric or Imperial?
Heard a story that early 108/109 second stage diaphragm clamp screws were Metric and later changed to imperial #4-40.

 

[Couv]

Fibonacci,

Yes, SP has been known to use both imperial and metric, and you head correctly about the band clamp hardware.

I cannot be sure if these are the same size, but if you're still having issues with your BC after replacing the seals, consider replacing the elbow assembly with parts found here.
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