NPT threads performace data 5

[toriche]

Does anybody have information about the performance of NPT threads at high pressures (10-15 KSI)? Any publications, performance tables or the like will be very helpful.
Thanks for reading my questions.

 

[FACS]

Do you mean, high pressures that make them leak or high pressures that cause stress/strain relationships?

Charlie

http://www.facsco.com

 

[Philrock]

Properly made NPT threads can work at high pressures. A number of companies make fittings rated for the pressures you're talking about. Swagelock and Hoke, to name a couple.

McMaster-Carr stocks high pressure fittings from several manufacturers.

 

[sairaj]

Please do consider this facts too , whether the said NPT threads of your system is Jointing type or Fastening type .

Normaly sealing effect is improved by a joining or filler compound for NPT Threads (usually teflon ), for temperature and high pressure application this fails and then it is better to go for NPTF Threads through tapping.

 

[toriche]

Charlie,
Both cases would be of interest to me.
Thank you.

 

[tnkayaker]

We use NPTF threads with grease pumps that produce 15 KPSI of pressure without incedent.

 

[unclesyd]

Most of the previous comments are for the smaller diameter threads. It has been my experience that anything above 1/2" requires very careful threading and checking.

Can you comeback with a little more details about your application?

 

[stanier]

Fatigue is also a big consideration with threads.

 

[arto]

MIL-STD-777 doesn't allow pipe threads, ASME Sec. VIII Div 2 warns about the "possible deleterious effects" of pipe threads. How about SAE O-Ring fittings?