Tank Valve Descriptions

[Wijbrandus]

I need a refresher on the different kinds of tank valves.

Does anyone know a website that has pics and explains what purpose each different kind serves?

All the searches I've done either take me to someone that sells them, or talks about them, but they all assume you know what they are. I need something that explains it with a bit more detail.

Thanks.

 

[Walter]

Do you still have your OW text?

 

[Wijbrandus]

I do. I'll look at it again tonight. I believe however it only talked about K-valves and DIN, not some of the other less-common types like H-valves.

It's on the list. The book was packed away by an over-eager spouse, and I have to get it out of storage.

 

[simbrooks]

I know my OW text didnt really cover the less common types of valves. It was only looking around on here and other online resources that clued me up on H valves, manifolds, the difference between 232 and 300 bar DIN and how you can use a yoke insert in 232 bar DIN, the tank neck sizes for HP and LP steel tanks.

The OW text did suggest about J and K valves, particularly K as they are very common, particularly for rental tanks used in most OW training. It gave only a brief sentence about DIN valves, so not really much help. I hope others can help you on this quest.

 

[Bob3]

"K" and "J" were the catalog letters of the plain & reserve valves from the June 1953 US Divers catalog.
"K" is an indication that a valve does not come with a built in reserve. K's can be either yoke or DIN.
"Y" and "H" valves weren't around back then, and describe the actual shape of the valve.
DIN valves were in use in Europe.

http://www.geocities.com/athens/atlantis/2427/divecat/index.html

 

[Walter]

I have the 1955 catalog. Not much changed.

 

[roakey]

All DIN: K valve, H valve and the two flavors of current manifolds:

http://www.genesisscuba.com/images/din_full.gif

Y valve:

http://www.beuchatdiving.com/webart/tnk_vlv1.jpg

Note that this is a 200BAR valve, and it shows how the yoke "donuts" screw into the DIN port. This is also sometimes called a "slingshot" valve.

Both the H and Y valve allows equipment redundancy (two first and second stage regulator pairs), such that one regulator set can be shut down in case of freeflow (for example) and the diver still has a functioning regulator.

These solutions, however, do not give you GAS redundancy, which only a double tank isolation manifold gives you (or *gasp* independent doubles).

Roak

 

[Wijbrandus]

Thanks, Roakey. Those two pics have answered my questions perfectly.

What would be the purpose of using Y or H valve systems? It seems to me that they would simply overly complicate a single tank setup.

 

[simbrooks]

H and Y are used with two independant 1st stages and subsequent hoses routed off of those. It gives you redundancy in case of O-ring failure or 1st stage freeflow failures, so that you can still use the gas in the tank rather than blowing it all with a free-flowing reg etc.

The particular use of these is in overhead diving with single tanks, where you cant just do what you practiced in OW training where on a freeflowing reg you ascended whilst sipping off the freeflowing reg. You cant afford that kind of gas loss in an overhead environment as you cant directly ascend. So you turn off that part of the valve which is attached to the freeflowing reg and move over to your redundant one. Just keep an eye on your gas though and almost all the redundancy is there (except using doubles).

It is overly complicated for an OW dive, but in overhead it can mean a lot!! BTW the Beauchat Y valve is about twice the price of an H set-up, but you can use the main valve part of H valve set-up (the one that is attached to the tank) as one of posts in a doubles set-up. It was suggested that i buy one left and one right valve with H valves to ease the financial burden marginally of moving to doubles later thru the intermeadiate step of a redundant 1st stage, but in the end i am going with regular valves and on to doubles, without passing through the H or Y valve territory.

 

[Wijbrandus]

Very nice. Thanks for the info. I'll call this reeducation complete now.

Though I still need to grab that PADI book and see if this was covered and I'm just a knucklehead...