Service for HP Swivel

[d^2b]

I want to use the pictured swivel (that I bought in the 1990s) to mount a transmitter to a Dive Rite FT1 first stage (it's pretty cramped with 2LP hoses already there).

It seems to work OK (on land), but I'm concerned about the guts of the swivel after several decades on the shelf. I'm guessing there are some o-rings inside that should probably be replaced. Probably dumb questions:

1. Does it most likely need service? The o-ring outside was in good shape (although I replaced it anyway). It has never been in the water, but the internal o-rings (assuming they exist), must be getting on. It seems to hold pressure fine on the surface, but a failing HP hose (equivalent) isn't that much fun.
2. Do I need some specialized tool to remove the ring holding the swivel together? (I want to say cotter pin, but it's obviously not a pin).
3. Will I need a new "ring of holding things together" after re-assembly?

If it helps, this thing was originally made by National Divers Manufacturing in California, with part number 12238

Looking at [1], it seems like the fastener-I-can't-name might be called an "e-clip"

[1]: OmniSwivel O-Ring Kit for OSI-QDM-YFI

 

[Mobulai]

Funny you should ask, I was cleaning my regs in the bathtub (with a pony) and first I thought I saw a hair on the surface; but then I noticed that it’s the tiniest of champagne bubbles (like scale to the size of an ant), coming from one of these
I was just wondering that I should service it/open it for check up
I got mine this March btw

1. Yes, I would worry more about the internal Oring (dynamic, HP) — probably a sh90 with good lubricantion
2. Not really, I mean you need a circlip plier, pretty generic but specific enough
3. Probably not unless it’s in state (really rusty/feels brittle)

HP leaks funny enough are very öow flow (compared to LP), I think why they have that tiny hole in the port itself

 

[d^2b]

Oh I see. The clips without tabs are probably called "c-clips".

 

[Mobulai]

[1]: OmniSwivel O-Ring Kit for OSI-QDM-YFI

Thanks for that — just what I was looking for

 

[Umuntu]

Oh I see. The clips without tabs are probably called "c-clips".

External Circlips. Also known as retaining rings or c-clips.

 

[d^2b]

I managed to disassemble, but the inner (dynamic) o-rings seem to be a non-standard size. Measured with digital calipers, they are really 1/16=0.0625" cross section, as opposed to the 0.070 AS sizing. The AS012 o-rings I had on hand are 90 durometer. I don't know if if is the size or the hardness, but the o-rings don't fit. If pushed enthusiastically the steel outer cylinder will shave bits off the o-rings (oops). Should I get some softer AS012 and hope for the best, or are there some standard O-ring sizes that are actual 1/16" as opposed to nominal? Searching somewhere like Amazon is a drag since everybody seems to advertise by nominal size.

 

[d^2b]

After reading Sizing and Selecting O-Rings for SCUBA | Dive Gear Express® , I'm inclined to try the shore 70 AS012 o-rings. I also realized that it is tricky to get the cross section for a shore 70 o-rings with a caliper, since it is easy to distort them. So my reading of "thinner" might really mean "squishier".

 

[Mobulai]

So my reading of "thinner" might really mean "squishier".

I try to average quite a few readings to mitigate that effect with soft stuff (like lp seats), but barely helps, then I try to interpolate on metric and imperial units and see what kinda makes sense to be closest

 

[lexvil]

I would just spend the $20 to replace it.

 

[d^2b]

I would just spend the $20 to replace it.

Yeah, if I had the equivalent of dive gear express in Canada I probably would have just done that already. I was kindof excited to find a use for a gadget I had literally carried around with me for 25 years and several countries, but at this point I have to value the learning experience for the project to make sense.