New 7/8-14 UNF Tank Valves

[Kensei]

I am assuming you are referencing this catalog from 2004.
https://www.scubaengineer.com/pictures/valves/thermo/thermo_catalogue.pdf

I agree that the current 7/8"-14 XS Scuba DIN valve looks like it may be identical to the older Thermo version but with a different hand wheel. It would require an explanation from XS to understand why one is Air Only and the other was EAN Ready 15 years ago.
I can only think of 3 possibilities: there may be an actual non-obvious design difference, there may be a change in standards/regulations, or there may even have been a change in specs based on new info from a negative experience or two.

Sorry, I am not aware of any current manufacturer valves that say EAN suitable for a 7/8"-14.

Yes, that is the catalogue and the item. I guess my next stop is to ask XS directly why the new valve is air-only... in the ScubaBoard XS Scuba manufacturers forum.

 

[JackD342]

I suppose you could also try reaching out to Trident to ask about EAN. They sell a valve described as "PN:A245, 300 Bar DIN valve 7/8"-14 fits PST and Genesis"

No branding info in my dealer guide and no specs, but that is par for the course with them.

 

[JackD342]

@Kensei
Just to double check - the tanks you have with those older Thermo valves are definitely 300 bar DIN and not yoke, right? If there is nothing obviously wrong with them, they will probably last you forever with proper care and maintenance, no need to start planning their retirement party.

I took another good look at the XS catalog, and it seems that the rule for anything "Air Only", either XS Scuba or Thermo brand, is that the 300 bar DIN valves and the K valves are all Air Only, while the EAN valves are any and all of the convertible Pro valves, DIN 230 bar.

So I am betting that the spec difference between the old 7/8"-14 Thermo and the current XS 7/8"-14 is a matter of a change in rules rather a change in design. Maybe some of the same changes over time that eliminated 3500 psi tanks and valves from specs in the US, replaced with 3442 psi spec items that just squeak by under the newer rules.

 

[Kensei]

@Kensei
Just to double check - the tanks you have with those older Thermo valves are definitely 300 bar DIN and not yoke, right?

I took another good look at the XS catalog, and it seems that the rule for anything "Air Only", either XS Scuba or Thermo brand, is that the 300 bar DIN valves and the K valves are all Air Only, while the EAN valves are any and all of the convertible Pro valves, DIN 230 bar.

So I am betting that the spec difference between the old 7/8"-14 Thermo and the current XS 7/8"-14 is a matter of a change in rules rather a change in design. Maybe some of the same changes over time that eliminated 3500 psi tanks and valves from specs in the US, replaced with 3442 psi spec items that just squeak by under the newer rules.

My current 7/8-14 valves have a working pressure of 3500 PSI and are DIN-only... so no, they aren't 300 bar. In the 2004 Thermo catalogue you linked to, you can see that the old valves are 3500 PSI working pressure. My understanding is that since the working pressure is above 3442, then they have to be DIN-only.

The new 7/8-14 valves have a working pressure of 4350 so they are 300 bar valves. So that is at least one functional difference between the old and new 7/8-14 valves.

 

[guruboy]

My current 7/8-14 valves have a working pressure of 3500 PSI and are DIN-only... so no, they aren't 300 bar. In the 2004 Thermo catalogue you linked to, you can see that the old valves are 3500 PSI working pressure. My understanding is that since the working pressure is above 3442, then they have to be DIN-only.

The new 7/8-14 valves have a working pressure of 4350 so they are 300 bar valves. So that is at least one functional difference between the old and new 7/8-14 valves.

The DIN connection on your valve is the 300bar depth. Even if the tank and regulators are not actually operating at the full 300bar pressure.

The DIN/Yoke convertible valves use the 230bar DIN connection.

 

[rjack321]

My current 7/8-14 valves have a working pressure of 3500 PSI and are DIN-only... so no, they aren't 300 bar. In the 2004 Thermo catalogue you linked to, you can see that the old valves are 3500 PSI working pressure. My understanding is that since the working pressure is above 3442, then they have to be DIN-only.

The new 7/8-14 valves have a working pressure of 4350 so they are 300 bar valves. So that is at least one functional difference between the old and new 7/8-14 valves.

The only difference is the burst disk which is based on the cylinder. Your current valves have 300 bar threads and if they are going into 3500psi cylinders they should have 5250psi burst disks.

The 4350 valves also have 300 bar DIN threads, just 6525 burst disks instead. Since you have 3500 psi tanks you need the 5250 burst disks anyway.

But Why replace the valves at all?

 

[Kensei]

The DIN connection on your valve is the 300bar depth. Even if the tank and regulators are not actually operating at the full 300bar pressure.

Thanks... I did not realize this important distinction until now.

 

[happy-diver]

I suppose you could also try reaching out to Trident to ask about EAN.

Like this?