Can you please confirm valve threads ?

[Externet]

Hello.
A 3/4" - 14tpi UNF CGA850 valve minor male thread diameter is 0.68" (17.287mm) and 0.75" major (19.05mm) ?

A 7/8" - 14tpi UNF CGA850 valve minor male thread diameter is 0.80" (20.45mm) and 0.875" major (22.22mm) ?

Do I have these numbers right ? There is no other modern valve threads in inches after the 1/2" NPT (or is it NGT ?) of the sixties, right ?

 

[Dsix36]

There are metric ones though

 

[Externet]

Hello.
Anyone with a valve removed from the tank at the moment; can you please measure the thread in your valve, not what the documents/specs may say/show on a web site link ? (a parallel one, not tapered)
Is it 0.700" or 0.740" or 0.750" or 0.875" or other ?

 

[tbone1004]

Hello.
A 3/4" - 14tpi UNF CGA850 valve minor male thread diameter is 0.68" (17.287mm) and 0.75" major (19.05mm) ?

A 7/8" - 14tpi UNF CGA850 valve minor male thread diameter is 0.80" (20.45mm) and 0.875" major (22.22mm) ?

Do I have these numbers right ? There is no other modern valve threads in inches after the 1/2" NPT (or is it NGT ?) of the sixties, right ?

View attachment 916027

Which part of the valve are you actually looking for?
The PST and Asahi 3500psi tanks have a 7/8-14 UNF and are often referred to as "skinny neck".

The standard scuba valve on the tank side in the USA is 3/4 NPS, not UNF.

The DIN outlets are 5/8-14 BSP

In Europe they have some other wonky tank side sizes, particularly M25, but I have never seen or heard of one that is legal for use in the US with a DOT stamp.

I have never heard of a scuba tank that uses 3/4-14 UNF, not to say it doesn't exist, but if it does it would definitely be considered nonstandard and there are no modern valves made for it.

No need to measure, they are defined standards.