Vintage Double Hose

I've ordered the DSV kit to have on hand. Unfortunately, living a few thousand miles away from the US on a small island things can take weeks to months to get here. Is there an off the shelf replacement for the o-rings that can be used?

I think all five orings may be the same size. Try swapling the the one you think is leaking with the one holding the wagon wheel in place. If that doesnt work, you can take one to the hardware store and see if you can match it up in the plumbing parts bins.

I'm in the same boat located in Australia with expensive and slow Post-CV-19 mail.

The DSV takes standard AS-568 o-rings:
-028 for the inner barrel and mouthpiece port x 3
-027 for the wagon wheels x 2

Usual spec is 70 Duro (Shore A) but I had much better results with softer and more compliant 50 Duro

I designed the O-ring groove clearance in the DSV for size -028 O-rings, but I have also used some metric: 2mm x 35mm. It is a bit thicker (2 mm = 0.078 inches, versus 0.070 inches for standard O-ring).

Even with the thicker O-ring I have not had any issues, but molded parts do have some variations due to tolerance.

The thicker metric O-ring (2mm x 35mm) will create a tighter seal if the tolerance on the parts runs on the looser condition. The trade-off is that it can be tighter and harder to rotate if the two cylinders are already running tight to each other.

Good silicone grease lubrication is always critical. There is always the concern of too much grease collecting debris, but I have not had that issue.

I do not see any issues using the softer 50 durometer O-rings, but so far I have had good luck with the 70 durometer.

It would be interesting to try the thicker metric O-ring (2mm x 35mm) in 50 durometer, but I am not sure where I could find that. I buy most of my O-rings from Mc Master- Carr.

Thanks for the updates Luis, yes be interesting to try 2.0 x 35mm o-rings in 50 Duro but they certainly seem scarce vs the usual AS-568.