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.

 

[Jake 10]

 

[rjack321]

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.

He's talking about CGA 580 valves not scuba valves (well maybe not - but it's confusing since CGA 580 is an inert gas valve yet the rest of the OP's questions seem to be about scuba valves). There are fat and skinny threaded CGA 580s and they are also available in 0.75" UNF. But 0.75" UNF is a defined standard and there is zero reason to measure it. And 0.75" UNF is not 14 tpi it's 16.

 

[TravisD]

Just to confuse things even more, OP asked about CGA850 which is the common scuba yoke valve, not CGA580.

 

[tbone1004]

@rjack321 I was going off of what @TravisD said, the CGA850 cited is the yoke outlet standard so I was assuming scuba tank since that is about the only place you see them. I threw the DIN stuff in just for extra reference material, but either way the important part to the OP is that these are defined engineering standards with legally defined tolerances so there is no point in measuring them since the drawings are very clear.

 

[rjack321]

@rjack321 I was going off of what @TravisD said, the CGA850 cited is the yoke outlet standard so I was assuming scuba tank since that is about the only place you see them. I threw the DIN stuff in just for extra reference material, but either way the important part to the OP is that these are defined engineering standards with legally defined tolerances so there is no point in measuring them since the drawings are very clear.

Yeah maybe? Lol

@Externet 's whole initial question is a mess

 

[Externet]

Got it.
To post #3, diameter is 26 mm, or 1.02"