Best way to remove tank valve?

[DA Aquamaster]

Definitely good advice, but I always remove the burst disk (slowly) before removing the valve. Loosening the burst disk a couple of threads is the easiest way I have found to insure the tanks are empty if the valve handle is inoperable.

If there is any possibility that the tank has O2 in it, do not attmempt burst disc removal and also do not attempt to try to remove the valve if you cannot get the valve open. The tank can and probably will explode as the friction of the threads creates an ignition source for the O2 and oxides in the tank.

In general use an open end wrench that fits the valve, if flats are provided on the valve. If no flate are provided and you have to use the face and back of the valve for "flats", use hard wood (oak) strips between the valve and the jaws of a pipe wrench.

Alos note that if the valve is hard to remove, the potential to gall the threads in an aluminum tank is significant and if that occurs you now have 30 pounds of scrap aluminum, not a scuba tank.

 

[Leadking]

Use a smooth jaw wrench and it won't leave the marks like a typical pipe wrench.
Smooth Jaw Wrenches

Smooth jaw wrenches used to be called "monkey wrenches". Now you need to decide if it calls for a right-hand or left hand!

 

[Wookie]

The best luck I've had without damaging anything is to: Turn the cylinder upside down in a machinists' vice. Clamp the hell out of the valve flats in the vice. If you do this, the cylinder will not slip, and the valve will not be dinged. Wrap a strap wrench around the cylinder and put a significant cheater on the strap wrench. I use the same strap wrench that I use on my Detroit Diesel oil filters. If after you apply all the torque you can apply and it still doesn't move, have your wife beat on the bottom of the cylinder with a rubber mallet to shock the cylinder. I haven't had it fail yet, and I don't round the flats of the valves either.

 

[oxyhacker]

Or Moncke, to give credit where it is due ;-)

Smooth jaw wrenches used to be called "monkey wrenches".

 

[knotical]

Or Moncke, to give credit where it is due ;-)

Neat; but alternatively, quoting:
Charles Moncke@Everything2.com

Charles Moncke was a London blacksmith; according to legend he invented the monkey wrench. A difficulty with this theory is that the British call a … wrench a spanner. In 1932-33, the Boston Transcript traced the invention to 1856, crediting it to a Yankee named Monk, employed by the firm of Bemis and Call in Springfield, Massachusetts.

We may never know.

 

[Dive Raja Ampat]

In Cambodia we used a large Tie Down Strap attached to a concrete telephone pole. We used a large crescent wrench and a cheater bar. Works real well, the trick is to keep the tank from moving.
if the valve is not working most times is that the hand wheel is stripped, replace the hand wheel and then bleed air .
Of course if the valve still works, the best test that the tank is empty is to have valve open and blow into the tank and should fill up to about 7 bar and you can feel on your cheek. the danger is if you let the air out fast you could have ice build up and still have lots of pressure so always a good idea to blow hard into valve to check, if the valve is cold, before you pop the top.
When you put it back together don't forget liberal amount of silicon in threads. For tanks with more that 32% Oxygen have a certified tech work on, Oxygen is what they use to fuel the space shuttle! (O2)

 

[ajtoady]

I would a) make sure tank is empty, b) try to get some soapy water into the tank, it shouldn't take a lot, and c) after getting soapy water in invert tank for a few and allow liquid to penetrate the valve threads. You are removing the valves anyways so a hydro, cleaning and vis is in order. If there is in fact a scale or oxidation in the threads soaking from the outside does not get past the O-ring. Last resort, after making sure tank is empty, cut in half for a cool little grill for burgers and hot doggies, yum!!!

 

[sealark]

The best luck I've had without damaging anything is to: Turn the cylinder upside down in a machinists' vice. Clamp the hell out of the valve flats in the vice. If you do this, the cylinder will not slip, and the valve will not be dinged. Wrap a strap wrench around the cylinder and put a significant cheater on the strap wrench. I use the same strap wrench that I use on my Detroit Diesel oil filters. If after you apply all the torque you can apply and it still doesn't move, have your wife beat on the bottom of the cylinder with a rubber mallet to shock the cylinder. I haven't had it fail yet, and I don't round the flats of the valves either.

Listen to the above post, if this doesn't work scrap the tank. best suggestion here...

 

[rhwestfall]

2010 thread....... think he is still working on the tanks? How many grills or wind chimes do you think he has by now?

 

[sealark]

I guess it helps to look at original post date.