[philPKP]

IS THIS NPT THE THEAD SIZE?..PHIL <img src="confused.gif" border="0">

[EBlack36]

National Pipe Thread. It is a term from plumbing.

[6567GTO]

What Eblack said and it's tapered.

[philPKP]

HI GUYS, IS THIS WHAT WE OVER THE POND WOULD CALL A GAS THREAD!I HAD A EARLY RANGE ROVER ONE TIME + WAS TOLD THE MAJORITY OF PLUMING IE.BRAKES,FUEL PIPES ETC.,WERE A GAS THREAD? BECAUSE THE RANGE ROVER ENGINES WERE DERIVED FROM BUICK BLOCKS + DETUNED TO 3.5ltr THE PLUMING (missed that bleedin "B" out agin!!) WAS AN AMERICAN SIZE THREAD?
I"VE JUST GOT A HOLLEY "RED" FUEL PUMP BUT I GOT NO UNIONS,SO THE ONLY IMFO I"VE GOT TO GO ON TO ACCQUIRE NEW ONES IS 3/8" NPT....PHIL <img src="confused.gif" border="0">

[4 Jaw Chuck]

Gas pipe is normal schedule 40 black iron pipe.

[6567GTO]

I would say you're right - that it's a gas thread. But, I've never heard it described that way. It's a tapered thread used to seal gases and fluids.

Look at column 3 in this link...

<a href="http://www.plumbingsupply.com/pipethreadsizing.html" target="_blank">pipe threads</a>

[Kevin45]

NPT stand for National Pipe and the "T" stands for thread and is tapered. NPS is National Pipe Straight. The size will be determined on the tap. Which for most smaller applications are around 1/4" or 1/8" NPT. Although a 1/4" and 1/8" is considerably larger than 1/4" and 1/8" respectively. The taper is so the tighter you turn it the tighter it seals. Check these sites.
www.ind-supply.com/threads.html
<a href="http://ourworld.compuserve.com/homepages/MJVanVoorhis/T103.htm]http://ourworld.compuserve.com/homepages/MJVanVoorhis/T103.htm[/URL]

Hope this helps you out.

Kevin

[adtkart]

As Kevin said, the 3/8" NPT is larger than regular 3/8" tap. Pipe sizes are from the Inside measurement of the pipe, not outside as with bolts. I thought that usually the threads going into the body of the carb are usually straight , not tapered. Usually they use different types of fittings.