Using silicone grease with nitrox at low pressure

[Hatul]

I took apart the BC inflator and greased the O rings and threads with regular silicone grease.

I mostly dive with air but want to be able to dive with low O2 nitrox (say up to 34%). Any problem with silicone grease at the low pressure side? Has there been any documented fire with this?

Adam

 

[knowone]

I use silicone on external of o ring threads to retain unscrewability because the other stuff is expensive. I also swap everything for EPDM because it is the same price 100% 02 compatible and the minimal amount of grease required on pressurised o rings does not make any difference.

Saliva is good enough because once equipment is assembled and moving o rings move, the grease is wiped off anyway and only sits around the peripherals gathering foreigners and turning to gunk..

Rule No 1.000 used to be crack your valve slowly. It' still there somewhere.

Fire or explosion is generally associated with a silicone FILLED reg hooked up to 100% 02.
If these regulations did not exist, home fixing people may be tempted to apply grease like spread to bread because it seems good.
In fact some reg techs would be tempted to do so too and they do too.

 

[herman]

All I use is silicone and my regs see a lot of 32%. The entire nitrox thing has gotten blow way out of proportion. If you are using pure O2 then special lubes and orings are not a bad idea but for 32/36 nitrox, its overkill.

 

[Gilldiver]

I took apart the BC inflator and greased the O rings and threads with regular silicone grease.

I mostly dive with air but want to be able to dive with low O2 nitrox (say up to 34%). Any problem with silicone grease at the low pressure side? Has there been any documented fire with this?

Adam

As your item is a BC inflator, it should never see any more O2% then what is in your back gas, so what do you dive - 32/36/40?

The danger points with O2 seem to be above 400 PSI and O2%'s above 50 to 60+% which is why the 40% "rule" is used by some. The LP hose is usualy 150 PSI or less but you could have a HP seat fail and get higher, but in that case your 2nd stage would free flow before hitting much above 200-250 PSI.

In other words, don't worry about a BC or dry suit inflator, tanks, tank valves and regulators, at least the 1st stages, are another matter.

 

[Hatul]

Thanks. That was my thinking about it. I actually have a tube of Tribolube 71 that I bought at the dive show, but I prefer the feel of silicone grease.

The problem I was having is a sticking inflator button on the Zeagle BX inflator and I thought the silicone would make better grease for the plunger that works the Schraeder valve inside. I think the problem was that all the grease was gone and the O ring was sticking against the inflator body.

Adam

 

[Gilldiver]

Thanks. That was my thinking about it. I actually have a tube of Tribolube 71 that I bought at the dive show, but I prefer the feel of silicone grease.

The problem I was having is a sticking inflator button on the Zeagle BX inflator and I thought the silicone would make better grease for the plunger that works the Schraeder valve inside. I think the problem was that all the grease was gone and the O ring was sticking against the inflator body.

Adam

I have seen many inflators with your problem and it all comes down to corrosion on the plunger shaft. You may need to take the inflator appart and clean it all up.