Correct Thread Sizing

[b_thomas]

Putting this one out there for in hope that someone knows how thread sizes work (1/2", 3/4" etc.). More specifically someone who's bought a 1/2" Stainless full bore 2 piece (Grain and Grape) fitting and connected a Skin Fitting to it.

I'd recently purchased a 1/2" Ball Valve and a 1/2" skin fitting, when I try to thread the Skin Fitting in to the Ball Valve it's too small.

The outside diameter of the skin fitting thread is 17mm. The outside diameter of another fitting that does fit into the Ball Valve is 20mm.

So it appears as though the 1/2" Ball Valve has 3/4" thread. I'd like to be able to buy the correct size Skin Fitting rather than waste another $35.

 

[shaunous]

Im not sure what a skin fitting is referring to, but i beleive your problem would be the ball valve is a plumbing fitting, meaning its internal diameter is actually 1/2" or 13mm as your talking metric, not the ouside diameter, which is what hydraulic fittings and such use.

Just another way to confuse u.

But just measure the ball valve I.D. and you'll probably find its 1/2". so you'll need a 'skin fitting' that may be 3/4 to match. Not sure without having them sitting in front of me.

 

[wide eyed and legless]

1/2 inch B.S.P is almost 21 mm O/d

 

[b_thomas]

Cheers, plumbing vs. hydraulic may just be the problem.

A 3/4" skin fitting will look to do the trick - LINK

Cheers,

 

[wide eyed and legless]

Those skin fittings are BSP, looks like whoever sold you the 1/2 inch actually sold you a 1/4 inch BSP,
he just measured the o/d of the thread.

 

[sp0rk]

Cheers, plumbing vs. hydraulic may just be the problem.

A 3/4" skin fitting will look to do the trick - LINK

Cheers,

I guess you're using it to drain from the bottom of a vessel?
I did the same thing for my filtering setup for firewater
1/2" skin fitting into 1/2" ball valve into 1/2" barbed fitting

 

[shaunous]

Those skin fittings are BSP, looks like whoever sold you the 1/2 inch actually sold you a 1/4 inch BSP,
he just measured the o/d of the thread.

How can they be BSP if they run a flange nut?? They'd have to be parralell thread.

 

[davedoran]

Maybe its metric thread. 12mm. That is parallel as far as I know.

 

[wide eyed and legless]

BSP are machined either as parallel and taper,the one in the ball valve would be tapered.

 

[shaunous]

yeh true that, i was thinking of BSPT