K-Valve torque mallet

[jim99]

Any problem with whacking the handle on a K-valve with a rubber mallet in order to torque it down?

 

[Scubaroo]

See this thread, esp. NetDoc's response:

http://www.scubaboard.com/showthread.php?s=&threadid=12413

 

[The Chairman]

after that endorsement, even -I- had to go read what I said... :tease:

 

[roakey]

NetDoc once bubbled...
after that endorsement, even -I- had to go read what I said... :tease:

And it's STILL wrong.

Ed Kasten, instructor trainer for PSI jumped all over a dive shop employee when, during the visual inspector class I was in, he seated the valve by putting a wrench on it and whacking it.

Hand tight. Any kind of torque requirement is an anachronism from the 1/2" NPT days.

Roak

 

[The Chairman]

who is PSI number #4 (very first class), and now owns and runs Florida Scuba Repair will tell you that to NOT torque a tank valve down is ASKING FOR TROUBLE!!! He knows, cause he showed us the extruded O-Rings from those too lazy to do the job right! All tank manufacturers have torque specs... the mallet on the wrench is FAR CLOSER than tightening by hand. The problem with hand tightening comes with any binding... you THINK you have it tight and you don't. When you hear the valve seat to the aluminum, you KNOW that the captured O-Ring will remain captured and NOT extrude through a tiny crack that might result from hand tightening. While I don't want to be anal and break out the appropriate crows foot wrench and torque wrench and then do the offset calculations to determine how much extra leverage I would get from being off center, I STILL want to make sure that the O-Ring has no avenue for escape. The pressure is relentless and it will eventually find the error WHEN you make one. While Mother Nature abhors a vaccuum; she just LOVES to vent pressure. Murphy was an optimist! Do all that you can to defeat his law.

But hey Roakey, it's OK if want to be horizontal when you tighten them thar valves. :tease:

 

[Bubble Boy]

Right on NetDoc!!! However, I am that anal guy that gets the crows foot out with the torque wrench.

The thing that makes my skin crawl the most is seeing the LDS touching SCBA units from from the local fire brigades and treating them to the hammer treatment. There are specific torque heads for these valves and each manufacturer has its own recommended torque value. Some manufactures such as MSA have more than three different torque values depending on the valve. The Compressed Gas Association also specifies torque values.

 

[FredT]

NetDoc once bubbled...
The problem with hand tightening comes with any binding... you THINK you have it tight and you don't. When you hear the valve seat to the aluminum, you KNOW that the captured O-Ring will remain captured and NOT extrude through a tiny crack that might result from hand tightening.
But hey Roakey, it's OK if want to be prone when you tighten them thar valves. :tease:

Aluminum?? Tanks Are STEEL! Steel is much less likely to bind. If in a hurry I make up valves by spinning the tank and snapping the wrist to tighten. Kind of like making a cylindrical impact wrench from the wrist.

Either way if slapping the valve with a mallet, slap a wrench placed across the hex or face, not the handle! Bent valve stems suck!

FT

 

[The Chairman]

Luxfer Torque Specs ... Of course SOME PEOPLE will argue with a sign post and take the wrong way home!

By all means, listen to the manufacturer of these tanks over any of us on the board. They designed and made them after all, and it is only prudent to follow THEIR reccomendations. You might want to also check out Luxfer Support Resources for some additional information on Luxfer Aluminum cylinders.

 

[TCDiver1]

How about using a torque wrench?

Torque in foot-pounds is difficult to measure in whacks and grunts:smash:

 

[Mouth Breather old]

I was told that I should screw on the valve as tight as I can by hand...then whack the handle a couple of times with the heel of my hand to tighten it.

Is this okay? Or am I seriously compromising my safety by not using a torque wrench?

The only valves I regularly undo are the ones on my 13 or 19 cf Pony's when I hand carry them on to a airplane.