Installing a Vintage K Valve on a Steel 72

[Art Challacombe]

Several years ago, I was forced to remove my J valve on my trusty US Divers steel 72 tank. The reason for the removal was the LDS refusal to fill tanks with J valves. “Safety” was their official rationale. So, I bought a used XS valve from them and got my tank filled.

The XS valve has served me well and i would recommend them to anyone. But unfortunately, I have several vintage short yoke regulators that have trouble fitting on this modern valve. So, I found an era correct US Divers K valve that will better serve my ancient regulators. I found a rebuild kit from Silent Explorers and installed it in the USD valve. Super easy, works and looks like new.

Now the hard part. The XS valve is on tight and won’t budge, even with a 1-1/2 wrench and a three pound hammer. The problem for me is keeping the tank from moving. I don’t have access to a tank vise, so it looks like I’m out of luck and dependent on the LDS. But no, I remember a trick I was taught by an old salt many years ago. So, I jack up my truck and put the tank under the wheel as I drop the jack down. Now the tank is immobile with 5000lb of Ford’s finest on top of it. Even with the wrench and hammer the valve is stubborn, but finally breaks free. On goes the USD valve and all is well. Anyone have other ways to change out valves?

 

[James79]

I use a spare cam band or a ratchet strap and strap it to the (4x4 inch) leg of my workbench... that and a big azz wrench/deadblow hammer combo.

 

[happy-diver]

Steady vertical tank at crown with hand and hit valve knob side with plastic hammer

Many valves don't have flats, wrenches don't work, slip off, mar stuff, for butchering

You don't hit wrenches tools with a big hammer do you do that with wheel nuts-lugs

Understand loosening things

If your wheel nuts are too tight, you stand or bounce on the tool, for a gradual crack

 

[John C. Ratliff]

If you have access to a set of double tank bands, band on another tank, put the tank with the valve to be removed away from you when you kneel on the near tank, and use that leverage to remove the valve.

Now, you didn’t state whether it was a 3/4 inch valve, or a 1/2 inch valve with tapered threads. The old tanks were the 1/2 inch tapered valve, and they required use of a heavy wrench along with teflon tape to achieve a seal. The newer valves required only a O-ring and hand tightening.

SeaRat

 

[happy-diver]

hand tightening

with a torque directly correlated to how much chipped paint and rust is at the top of the tank


These systems work well

Only with anti-butchering protection of rubber or aluminium or something

No butchering

But I dont know about the tank except for perhaps a makeshift yarmulke

 

[Akimbo]

You might find some useful information in this thread:
Scuba Cylinder Valve Installation

 

[AfterDark]

Never had that experience. I just do like @happy-diver posted stand the tank up and smack the valve with a dead blow plastic hammer. Two maybe three whacks and it turns.

When I have a stubborn bolt I'll turn it in the tighten direction, sometimes a bolt that won't move in the removal direction will move just a little in the other direction. The key is move, once it moves on way it's likely to move the other also. Does that work with tank valves? I don't know never had to do it with a valve.

 

[Gone for diving]

Really dumb question.... you sure the tank is empty.... MAKE SURE!!!
that will jam the threads...
But if it is npt it will be tight...
3/4 usually hit with soft faced hammer.

I have make a tank holder with a ratchet strap...

 

[John C. Ratliff]

Several years ago, I was forced to remove my J valve on my trusty US Divers steel 72 tank. The reason for the removal was the LDS refusal to fill tanks with J valves. “Safety” was their official rationale. So, I bought a used XS valve from them and got my tank filled.

Okay, I’m really curious about this rationale. Why is a J-valve a safety hazard for filling a tank? Could you ask them to explain their reasoning.

SeaRat

 

[Art Challacombe]

Quite honestly, I thought their policy on J valves was FOS and it pissed me off to have to comply with its removal. I think they just don’t take kindly to vintage diving equipment. They gave my custom homemade Hawaiian backpack and Conshelf VI some strange looks. But, they did a hydro and certified my steel 72 that hadn’t been certified for over 35 years, so I wasn’t going to argue with them. Besides, I have a half dozen completely restored Calypso J’s in my collection ready for use on my 72’s. And yes, the reserve’s all work as they should.