Tanks, questions

[dogfix]

I just picked up a couple of steel 72's. I had the opportunity to remove the valves and drop a light down them before buying. The interior of both tanks are mostly light gray with a small patch of flash rust in each. The original hydro's are 3-66 and 9-67. The last hydro's are 9-79 each. Both tanks have their original Voit J valves. I have yet to get them hydro'd.

These are my first steel 72's. I have been trying to bring myself up to speed on all things steel 72 related. But, I have a question regarding the valves. If I need to, can I swap out one of the Voit J valves for a newer K valve? One of the valves just doesn't feel right when I operate it and if I go to rebuild it and find that it's been trashed, I may need to replace it.

Any of your thoughts on this, and steel 72's in general, would be greatly appreciated!

[1969ivan1]

Yes, u can swap them out with any other 3/4 inch tank valve. Get rid of those boots though. They are ugly and make tanks rust IMO.

[Gilldiver]

The blow out plugs on both valves look like they may be the old lead ones, get new ones when you have the tanks hydro-ed.

[YankDownUnder]

J valves are very simple, but should be serviced every five years. There is a good probability that cleaning and lubricating them is all that is needed. You have classic matched set and it would be a shame to put new valves on them. The tanks are no doubt galvanized and you should not sand blast them. I would think you do as Rob suggests, and remove the boots. If there is rust, remove it with Naval Jelly from your local home depot and repaint the tanks. You have a good find and I encourage you preserve them as best you can. Congratulations, Steve

[WD8CDH]

Matched except those are USD boots on Voit tanks.

[antique diver]

The reserve mechanism won't last forever in these valves, so look inside at the rubber or composite tips on the inside end of the reserve stem assembly. Check the material carefully to make sure it isn't about to crumble and leave you with no reserve air because the air leaked around the seal during a dive.
The same basic Voit valve also came as a K model with a plug in the reserve side. You may want to do that if you are in doubt about the reserves or just don't want them. I would keep the Voit valves... they are easily overhauled and internal shaft seals are available. I may still have some extra plugs for the reserve end if you need them.

[dogfix]

Thanks for the replies! I have already removed the boots and checked the tank condition beneath them. No external signs of corrosion anywhere on the tanks. It is my intention to rebuild and place back in service both tank valves. I'm hoping that replacement burst disks are still available. Did Voit make their own tank boots?

I also noticed that the original o-rings, where the valve meets the tank, are V shaped. I'm assuming I can replace them with a standard o-ring.

I'm planning on taking a VIP Refresher course at Our World Underwater this winter. I thought it would be fun to take one of these tanks along as my test tank.

[WD8CDH]

I also noticed that the original o-rings, where the valve meets the tank, are V shaped. I'm assuming I can replace them with a standard o-ring.

yep, they were round when they were put in there years ago.

[antique diver]

The oring is just a standard # 214 that is widely available and should be cheap. Don't take a chance on leakage with the old ones.
The burst discs should be available from any real dive shop (as opposed to the more commonly encountered "dive boutique"). If you have trouble finding any of the parts just drop me an email. From the picture it looks like you have the original plugs retaining the discs. These don't have lead in them, and can be reused if you want to keep the correct vintage configuration... with one caveat: newer configurations have a hex head that covers the opening and diverts the air from a ruptured disc in several directions to keep the cylinder from being pushed around by the air jet. And more importantly, the head of the new type captures the loose piece of copper that may blow out of the hole you see in your existing plug.

[JES]

Nice score on the tanks. Congrats!