Luxfer scuba tank

[Nickfozzie]

Hi, i am looking to change my luxfer tank velves as the condition of them are not to good, my freind as some catalina tank valves for sale would the thread be the same?

 

[ajduplessis]

Depends where they come from.Typically UK luxfer have M25x2 threads and DOT have 3/4 treads if I recall correctly. They are not compatible even thou a M25 will screw into and3/4 thread. But for the love of the lord, dont do this. They will fail and hurt someone. Same applies for cat cylinders.

Why not service the current valve, you dont have to buy another. Simple to service!!

 

[Nickfozzie]

Hi ajduplessis thanks for your reply, can not service the one's i have, to far gone plus they have damage...

 

[DaleC]

You need to provide a few more details about the tank(s). I have USD brand Luxfers that swap with my Catalina.

 

[James R]

FWIW my two Catalina tanks came with pro-valves, and I wanted them in some Luxfer AL80 tanks that I have. The valves swapped without an issue. All are US sourced tanks.

If you buy used valves, I'd suggest you have them serviced and a get a little bit of lube on the threads.

 

[Johanan]

Could somebody tell me the difference between a M25/2 valve and a 3/4 or a 7/8 one? What do these numbers mean? Thanks!

 

[g1138]

M25 is a metric thread (millimeters). 3/4 and 7/8 are imperial (inches).
The difference between an M25 and 3/4 thread is very minimal, but it's not what you would call a perfect match.

Difference systems of measurement; just like SAE and metric sized wrenches.
Analogy would be 19mm wrench and 3/4in wrench. Pretty much the same thing just a few millimeters off from a perfect copy of each other. However mixing them up with 19mm nuts and 3/4 nuts can lead to your wrench slipping out or stripping because it's not a perfect match up.

 

[Johanan]

Many thanks, g1138!

 

[geoff w]

I just saw this thread, and am in the same predicament as the OP. I picked up a Luxfer Al80 from a buddy, and the valve is too corroded to service. I think my friend picked up the tanks while cruising on his sailboat in Australia. Is there some way to tell from the tank markings what the thread is for the valve? The second row of stamped markings on the tank shoulder start "DOT" so is it safe to assume it has a 3/4" thread?

 

[Scared Silly]

Is there some way to tell from the tank markings what the thread is for the valve? The second row of stamped markings on the tank shoulder start "DOT" so is it safe to assume it has a 3/4" thread?

Unfortunately cylinders made for the North American market do not have thread info stamped on them. However, if has DOT or TC (Transport Canada) stamping it is probably 3/4" threads.