What are best O-rings for Tank to Yoke

[HowieDean]

Which material works the best in rental tank inverionment... Lots of use..
Was thinking Viton would be best would like to learn from your experiance...

Thanks

 

[neil]

The teflon ones seem to last a very long time.

 

[captndale]

Which material works the best in rental tank inverionment... Lots of use..
Was thinking Viton would be best would like to learn from your experiance...

Thanks

There are two ways that most Yoke-to-valve o-rings are lost from rental tanks. The most common loss occurs when a student or novice diver fails to completely purge the regulator before removing it. The second, by far, is from wear.

The most common materials for o-rings are black rubber. They are durable and quite resistant to wear. They will, however oxidize when in contact with high levels of oxygen for long periods of time.

Viton is o-rings are usually colored either brown or green so that they can be differentiated from the black rubber ones. Viton is specifically used in applications which subject the o-rings to high levels of oxygen for long periods of time. They are resistant to oxidation. Viton, however, has very poor resistance to abrasion and wears out quite fast.

If you use viton o-rings for the yoke-to-valve connection you will find yourself replacing them quite frequently as they wear out. The faces in contact with the regulator quickly abrade and begin to leak.

Since, even with nitrox or even oxygen bottles, the o-rings only contact the oxidizing gas for a short time the use of viton in this application is not warranted. A viton o-ring will wear out from abrasion well before a rubber o-ring would fail from oxidation.

 

[Scottri]

Round ones I use plain old black rubber ones. They last a long time and they are cheap to replace when the go sailing away. Viton o-rings cost a bit more and for use with air make no sense to me.