Hiss and a pop when attaching my reg

[RIHappyDiver]

I bought a used yolk Faber MP-100 tank this past summer and lost the o-ring about 7 dives into the season. I replaced it with a viton 013, as the 014 seemed too large. I don’t use nitrox in the tank, but I do in my LP 85s, so viton was what I had in my save-a-dive kit. Since replacing the o-ring I usually get a hiss and a pop when I attach my reg, then it seals. I have had no gas leaking during dives and I haven’t lost any more o-rings. What am I doing wrong?
Mods, if this should be somewhere else feel free to move it.

Thanks,

Erik

 

[tursiops]

I bought a used yolk Faber MP-100 tank this past summer and lost the o-ring about 7 dives into the season. I replaced it with a viton 013, as the 014 seemed too large. I don’t use nitrox in the tank, but I do in my LP 85s, so viton was what I had in my save-a-dive kit. Since replacing the o-ring I usually get a hiss and a pop when I attach my reg, then it seals. I have had no gas leaking during dives and I haven’t lost any more o-rings. What am I doing wrong?
Mods, if this should be somewhere else feel free to move it.

Thanks,

Erik

The 013 is about 0.063 inches smaller in Inside Diameter than a 014. So what you are experiencing is the loss of gas while the yoke is sealing, then the o-ring compresses and all is well. Except it is not as good a seal as the correct size, and might fail sooner. I'd just use a 014. After a single yoke attaching and pressurizing, it will get pushed into the grove and fit fine.

 

[RIHappyDiver]

Thanks for the quick response, @tursiops, I’ll give it a try. I originally started to put a 014in it, but there was so much of it hanging out of the groove that I was afraid it would be cut. The 013, on the other hand, fit right in with no problem (which should have been my first clue that it was the wrong size).

Thanks again!

 

[JackD342]

Not uncommon. I use the plastic back end of my o-ring pick to work around the groove and press the o-ring into place.

 

[northernone]

With hiss/pop size orings I notice it is easier for them to extrude which leads to a very loud pop and loss of gas.

 

[Marie13]

I bought a used yolk Faber MP-100 tank

You’re not supposed to crack the yolks. Didn’t your OW instructor teach that?

 

[RIHappyDiver]

Thanks everyone, including you, @Marie13, for your input on my problem. I just replaced the 013 with a 014 and, using @JackD342 ’s tip, got it into the groove far enough that I could put the reg on, turn on the pressure, and push it the rest of the way into the groove, just like @tursiops said to. No more hiss and pop! This, hopefully, will keep me from hearing the loud pop and loss of gas that @northernone mentioned.

Safe diving!