leak around the o ring

[2divefor]

The last two times I went diving I noticed a small stream of tiny bubbles coming out of the conncetion where the regular connects to the tank. The first time it happened I replaced the o ring. That worked. But then the next day I had the same problem again, and this time replacing the o ring did not solve the leak. Help me out here. What is the problem and/or what should I do about this?

R

 

[scubasean]

The last two times I went diving I noticed a small stream of tiny bubbles coming out of the conncetion where the regular connects to the tank. The first time it happened I replaced the o ring. That worked. But then the next day I had the same problem again, and this time replacing the o ring did not solve the leak. Help me out here. What is the problem and/or what should I do about this?

R

Just for jollies, I'd check to ensure you are using the correct O-ring...

Also, how tight are you making the connection? Since the oring is supposed to supply the seal, Tighten just a bit tighter than finger tight.

 

[Spectre]

Check if the nut that holds the yoke assembly to the main first stage is loose. It's possible that's loose and the o-ring on the inside is the one that's leaking? *shrug* it might be worth taking in and having it taken a look at.

Does it happen only on that tank? It could be that where the o-ring sits in the valve is damaged.

 

[LUBOLD8431]

Good suggestions above, but also check the regulator where it seals against the oring. It might be nicked just enough to cause a leak...

 

[scubatoys]

And then if you can check that tank with a different reg, or your reg on a different tank... that will instantly trouble shoot on whether it is a problem with your reg instead of the tank. I've seen many a 1st stage that had just enough of a nick - and I've also seen a slight warp from someone having the tank fall over, the reg hits something, and it warps the yoke where it connects to te tank and never again makes for a good seal.

If you determine it's not the reg... and it happens even with new 0-rings... time for a new valve... A new tank valve will run under $25.

 

[Ontario Diver]

As said above; Easiest solution is an overtightened Valve. It can stretch the O-ring and ruin the seal. Some other things to check are the o-ring seats (The surfaces where the o-ring sits on.) They can be damanged or dirty which can sometimes cause the same problem.

Another possibility is cracked threads or neck of the tank. A good professional visual inspection can verify this.

 

[pescador775]

It is not possible to 'stretch' the O ring of a yoke system or DIN system. The valve annulus of the yoke system is designed such that the regulator rests against metal when fully seated. This is a designed in feature of valves made since 1977. The regulator must be screwed down until the connection is solid, much as when a valve is screwed into a tank. The most common problem with valves arises when clumsy removal of the O ring scratches the annulus. The entire valve must be replaced. If the valve is good replace the O ring with a white silicone type specifically designed for SCUBA valves. Buy it from a dive shop. If the regulator orifice is damaged, replace the nozzle. I don't know how these stories get started, eg that an O ring can be distorted by compression. Not technically possible. It is true, however, that old valves which used a thick O ring employed this ring as a crush washer. That is ancient history.

As said above; Easiest solution is an overtightened Valve. It can stretch the O-ring and ruin the seal. Some other things to check are the o-ring seats (The surfaces where the o-ring sits on.) They can be damanged or dirty which can sometimes cause the same problem.

Another possibility is cracked threads or neck of the tank. A good professional visual inspection can verify this.

 

[pescador775]

I'm adding to this as I scrutinize more posts. It takes careful reading to pick up on some more non trivial gaffes. For example, you are being told to tighten the yoke 'slightly more than finger tight'. This is not what USD originally had in mind when they designed their yoke with a huge plastic reinforced knob. This knob must be tightened down firm until you feel metal against metal. Do not depend on air pressure to seal the O ring. The valve is not designed to accomodate this and the O ring will migrate or extrude. This produces a nick or scratch in the rubber leading to failure including blow out. Grip the knob firmly and tighten until no further movement is possible. If the knob is difficult to unscrew, try putting some grease on the threads beforehand. Note that it is common for even a tight yoke connection to be subject to some rotation of the first stage body against the valve when forced. This is irrelevant and is caused by the low friction coefficient of the metal faces.

It is not possible to 'stretch' the O ring of a yoke system or DIN system. The valve annulus of the yoke system is designed such that the regulator rests against metal when fully seated. This is a designed in feature of valves made since 1977. The regulator must be screwed down until the connection is solid, much as when a valve is screwed into a tank. The most common problem with valves arises when clumsy removal of the O ring scratches the annulus. The entire valve must be replaced. If the valve is good replace the O ring with a white silicone type specifically designed for SCUBA valves. Buy it from a dive shop. If the regulator orifice is damaged, replace the nozzle. I don't know how these stories get started, eg that an O ring can be distorted by compression. Not technically possible. It is true, however, that old valves which used a thick O ring employed this ring as a crush washer. That is ancient history.