Help needed please! What size tapered thread is this?

[Tangledfeet]

It's on the drain valve from my FIAC 50l air compressor. I want to replace it with an elbow so I can convert to push-fit tube and then a drain valve elsewhere.

Thanks!

 

[Blobber]

3/8 I'd have said

 

[dave h 2]

Take it to your local plumbers merchant if you have one or sometimes the size is stamped on the hex flats

 

[Other Daniel]

3/8 I'd have said

I would 2nd that

 

[Munkul]

1/2"bspt,
at the top full form end it's a lot closer to 21mm than 17mm.

 

[Bullet2012]

3/4 BSPT, but i now nothing, just fancied putting something in the thread.

 

[Blobber]

 

[Fazerruss]

FYI, usually anything plumbing related is going to be a BSP or BSPT thread. This goes for gas, air and water etc.

 

[northwest]

I am going to agree with @Munkul on this one, 1/2" BSPT I would say. When will the winners be notified :-)

 

[Agroshield]

...usually anything plumbing related is going to be a BSP or BSPT thread.

As the machine is Italian, you are correct, but there are one or two people in a land to the west of us who might respectfully disagree with that statement in general terms. The market into which the machine is sold is important in providing possibilities.