Pipe thread engagement? 3

[DavidHP]

I am trying to learn the normal depth/lenght of pipe thread engagement. More specifically how far do commercially available 2" NPT pipe threads thread into a 2" NPT fitting?

 

[falcon4]

Machinery Handbook gives a good description of desired engagement. Keeping in mind variation in parts from various suppliers, conditions of threads, amount, if any, of thread tape, and the operator threading the fittings together.
Check ANSI B2.1 if you have access.

Also be aware of the existence "round" crest pipe threads used for Oilfield equipment that are not interchangeable with standard "V" threads.

Gary

 

[mrainey]

Check out the free program at:

http://bellsouthpwp.net/r/s/rsnmar/METhreads.zip

for extensive and easy to access data on many thread types, including NPT.


Mike Rainey (proud author)

 

[DavidHP]

Thank you Mike. Your program is very helpfull. Every ME should have one.

David

 

[Drazen]

Ther are many good sources, Machinery's Handbook being among the best: Nelson's Millwright & Mechanics guide/Mech. Trades Pocket Manual; IPT's Industrial Fasteners Handbook/Pipe Trades Handbook. You can pull out approximation for available hand "makeup" and demanded wrench makeup, which gives total makeup needed for adequate joint. You can express it in number of turns if you need it for specifications, having in mind that for commercial grade threads, tolerance will be +- 1 turn, which gives +- 2 turns totally for joint (that shouldn't be a problem for "normal" applications).