need help with npt threads

[FAVALADEZ]

we just scrapped 3500.00 dollars worth of parts because the id of the npt threads was too big. where can i find the id diameters of american standard npt threads?

[Karl_T]

Originally Posted by FAVALADEZ we just scrapped 3500.00 dollars worth of parts because the id of the npt threads was too big. where can i find the id diameters of american standard npt threads?

You need a machinery handbook. here's one page, lot more in the handbook.

karl

[djr76]

google works wonders - Basic Dimensions for NPT American National Taper Pipe Threads

[FAVALADEZ]

GUYS I APPRECIATE THE REFERENCE, BUT I STILL DON'T KNOW WHAT THE ID SHOULD BE. I LOOKED AT THE HANDBOOK, BUT I STILL CAN'T FIGURE OUT THE ID DIAMETER AT THE START OF THE 3" THRDS. HELP!!

[djr76]

I gave you the tools to do so. Buy a thread gage, or a npt plug to test the thread or even get a piece thats going to mate with your part. Do you have some kind of cad program to draw it out? how about you do some test pieces first. Never put all your eggs in 1 basket.