A quick question. When you install a hose onto a first stage do you lubricate the small O-ring or not? I am replacing a high pressure hose and console.
O-ring lubrication.
- Thread starter Kim
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Yes... but I wouldn't use silicone grease.... I use O2 compatible spit instead.
Not sure about the O2 compatible spit. It sure ain't 02 compatible if you just got done munching on some Doritos.
I would not get real concerned about using silicone on an LP hose if you are not using anything hotter than 40% O2.
For an HP hose on a reg that is used with any enriched o2 mix, I would use an O2 compatible lube like Cristolube.
If the reg is not going to be used with Nitrox, then a silicone based lube is fine on the HP hose o-rings.
With a static o-ring like those found in LP/HP plugs and on hose to first stage connections, the lubricant helps the o-ring slide into place and conform to the space where it needs to seat. Installing one with inadequate lubrication can prevent this from happening or damage the o-ring and compromise the seal.
I would not get real concerned about using silicone on an LP hose if you are not using anything hotter than 40% O2.
For an HP hose on a reg that is used with any enriched o2 mix, I would use an O2 compatible lube like Cristolube.
If the reg is not going to be used with Nitrox, then a silicone based lube is fine on the HP hose o-rings.
With a static o-ring like those found in LP/HP plugs and on hose to first stage connections, the lubricant helps the o-ring slide into place and conform to the space where it needs to seat. Installing one with inadequate lubrication can prevent this from happening or damage the o-ring and compromise the seal.
OP
Thanks everyone. I just wanted to do it correctly!
RichLockyer
Guest
You mean you want to do it.... right?KimLeece:
UP is right-on. The o-rings where lubrication is important are dynamic O-rings... those that are used in an area where there is motion, such as the HP spool and hose to 2nd stage. Of course, many of the internal o-rings are dynamic in nature as well, but you won't be working with those unless you're overhauling a reg, and in that case, we fall back to the standard answer of "If you have to ask the question, you need to learn more before you can safely use the answer"
Static o-rings, such as hose to 1st stage? Spit, or nothing is fine. You just want to avoid damage or extrusion, but once it's put together, the o-ring itself does the work and lube is not needed. One difference is with the large o-rings on camera and scooter housings, where a very light coating of silicone grease is good (just keep it away from the cat).
Scubaroo
Contributor
I can vouch for no lubricant being required on first stage/hose o-rings - I only use lubricant on dynamic o-rings now.
I wouldn't advocate silicone grease for anything other than lights or cameras - get some O2 compatable lub - it's like $10 for enough to last a couple of years. Silicone grease doesn't get anywhere near my regs anymore.
I wouldn't advocate silicone grease for anything other than lights or cameras - get some O2 compatable lub - it's like $10 for enough to last a couple of years. Silicone grease doesn't get anywhere near my regs anymore.
I'm not in the mood to disagree this morning but I will repeat myself and do it anyway since I think it is a bit irresponsible to disseminate bad advice on this topic.
A dry static o-ring runs a significant risk of not seating properly and it also has the potential to be damaged in the process. If it manages not to leak the first time, the odds are still greater that it will be at risk for leaking the next time it is removed and re-installed. It may not be dynamic but lubrication is required to help the o-ring seat properly.
Spit is certainly better than nothing for a lubricant, but I would regard it as a field expedient only. Installing a new "dry" o-ring may also work but only if there is enough lubricant left on the mating surfaces themselves from the last o-ring. O-ring material is also important and viton in particular is very suceptible to dmage from that kind of abuse.
Main o-rings on cameras are also static and I don't see droves of U/W photographers spit lubing them. If you won't do it with your camera, why take a chance and do it with your life support equipment?
A dry static o-ring runs a significant risk of not seating properly and it also has the potential to be damaged in the process. If it manages not to leak the first time, the odds are still greater that it will be at risk for leaking the next time it is removed and re-installed. It may not be dynamic but lubrication is required to help the o-ring seat properly.
Spit is certainly better than nothing for a lubricant, but I would regard it as a field expedient only. Installing a new "dry" o-ring may also work but only if there is enough lubricant left on the mating surfaces themselves from the last o-ring. O-ring material is also important and viton in particular is very suceptible to dmage from that kind of abuse.
Main o-rings on cameras are also static and I don't see droves of U/W photographers spit lubing them. If you won't do it with your camera, why take a chance and do it with your life support equipment?
OP
As far as camera's go - if you use silicon on Olympus O-rings they will eventually flood. Some camera manufacturers - including Olympus - use a special lubricant - it's NOT ordinairy silicon. Several people on this board have experience from floods due to using the wrong type.
DA Aquamaster - your advice sounds sensible - I'll follow it! The only reason I asked the question is that I know you don't use silicon on the tank O-ring - also the o-ring in the din connector on an Apeks first stage doesn't use it. It's supposed to be dry.
DA Aquamaster - your advice sounds sensible - I'll follow it! The only reason I asked the question is that I know you don't use silicon on the tank O-ring - also the o-ring in the din connector on an Apeks first stage doesn't use it. It's supposed to be dry.
Now why do you think that is?KimLeece:
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