lubricating new tank valves

[JBRES1]

I use quite a bit of banked nitrox in both of the 100's, (between 32%-36% mainly). Could you recommend a lube that would be good for those tanks? And should I have the valves taken apart and have them 02 cleaned? I believe they were ready for nitrox right off the bat. I bought them from Scubatoys, online. Is there anything wrong if I didn't put anything on the valves when I bought them?? I put the valves on before I got my Eanx cert. and didn't think about it.

Rob

You can use either of these lubes for o2 service.

Lubrication Technologies Christo-Lube MCG-111

Aerospace Lubricants TRIBOLUBE 71 - 2oz

The valves are most likely good for nitrox up to 40% from the factory, but that is for banked nitrox not partial pressure filles.
The valves being put on before you lubed them isn't going to hurt them if its just a few times. The valves are made of brass, and your tanks are steel. The brass would give way before the steel tank would.


As to the o2 cleaning, you are at the mercy of your local dive shop. Some shops require any cylinder be o2 cleaned if being used in Nitrox service while others don't.

I do my own o2 cleaning and fills, so everything I have is o2 cleaned weather its being used on air or Nitrox. Its easy to clean valves and cylinders for o2 if you know what you are doing, and have the time and tools.


If you want to get some background on cleaning and care of o2 cylinders read the Oxyhackers book.
Vance Harlow's OXYGEN HACKER'S COMPANION From AIrspeed Press


Good luck, dive safe and enjoy.

Jim Breslin

 

[Couv]

I'll confirm that the threads should be lubricated slightly - not much, maybe a bead half the size of a pea.
...snip...

The O-ring most definitely needs to be lubricated. It is extremely important that the o-ring slide into proper alignment with the mating surfaces on the tank and valve. If it si not lubricated this may not happen and the valve may not fully seat. If the valve does not fully seat, you do not have metal to metal contact and that will lead to o-ring extrusion.

It may seem counter intutitve but properly lubricating the o-ring will prevent extrusion not cause it.....

Time to educate me as I never attended a formal class on tank inspection. However, when I worked in a shop (20 years ago) the guy who performed the VIPs said that one should not lubricate the valve to neck o-ring as it would promote extrusion. This does not make sense for reasons DA mentioned above. However, a few referenced like the "Tips" page at Diveriteexpress.com and the Luxfer manual (1998) say to apply a very small about of lubricant at the bottom of the valve threads only. Same at the Catalina site (Nov 2005) http://www.catalinacylinders.com/valvescuba.html

Now I know, some of you must have more up to date information and techniques change, so what is the current consensus from the folks at PSI et.al.?

Thank you,

couv

 

[rjack321]

Now I know, some of you must have more up to date information and techniques change, so what is the current consensus from the folks at PSI et.al.?

Current consensus is to:
never re-use tank neck orings
do not lube tank neck orings
put a swip of lube on the valve threads before installation if otherwise unlubed, use less if they already have lube from last year

Dow Corning 111 silicon for air service
Cristolube for cylinders in partial pressure nitrox use

There's failsafe way eliminate extrusions or leaks, sometimes poo just happens.

 

[ScubaSteve85]

Resurrecting an old thread here to see if anyone knows how tight I need to torque down the valve onto a new Faber steel tank. Is this something I can attempt at home with a wrench or do I need to bring to the LDS?

 

[Wookie]

50 ft lbs, the spec is to have metal to metal all around the valve. What valves? The Blue Steel may not have flats, otherwise get the proper crow's foot have a blast.
If you have blue steel, you will need a special torque adapter that threads into the face of the DIN.

 

[ScubaSteve85]

50 ft lbs, the spec is to have metal to metal all around the valve. What valves? The Blue Steel may not have flats, otherwise get the proper crow's foot have a blast.
If you have blue steel, you will need a special torque adapter that threads into the face of the DIN.

Thank you!

 

[captain]

You are not going to tighten a valve to 50 foot pounds without a tank vice. All I have ever done is tighten the valve hand tight and then put the wrench on it and wack it with my hand.

 

[sealark]

I been working on tank valves for 50 years put the NEW o ring on, put the valve back in and make sure its snug in place. If you can get a wrench on it use it if not just tap the metal part with a rubber mallet. Make sure the tank O ring seat and valve are wiped down and clear of anything that could cause a leak. Why would you want to do more than that for a static sealing O ring?