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The 3/4" taper NPT threads (ANSI B1.20.1)
are full cut and hot galvanized after cutting.
Color-coded end-cap thread protectors keep
the threads clean and sharp and also provide
instant trade size recognition.
RIGID is threaded on both ends, with a coupling applied to one end and a
thread protector to the other. The pitch of the threads conforms to the
American National Standard for pipe threads, general purpose (Inch),
ANSI/AMSE B1.20.1. Threads are protected after cutting by an application
of molten zinc. The quantity in primary bundles and master bundles conform
to the NEMA standard bundle quantity.
NPT- National Pipe Thread Taper- ANSI B1.20.1
NPT pipe threads - dimensions according ANSI/ASME B1.20.1
Common American National Standard Pipe Taper Threads
NPT - National Pipe Thread Taper
FPT - female (internal) National Pipe Taper threads
MPT - male (external) National Pipe Taper threads
NPTF - Dryseal American National Standard Taper Pipe Thread (ANSI B1.20.3)
For NPT threads a sealant compound or Teflon tape must be used for a leak-free seal. For NPTF no sealant is needed for a sealing.
Characteristics of NPT (also known as ANSI/ASME B1.20.1 Pipe Threads, General Purpose):
tapered thread 1o 47'
truncation of roots and crests are flat
60o thread angle
pitch is measured in threads per inch
Note! Pipe sizes do not refer to any physical dimensions. The outside diameter of a pipe or fitting must be measured and compared to a table for size identification. A 3/4" NPT pipe thread has an outside diameter - OD - of 1.050 inches.
Each thread size has a defined number of threads per inch - TPI, or pitch. The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI and OD of the thread are required for positive identification of thread size because more than one size have the same TPI.
1) The taper is 1/16 inch in an inch, which is the same as 3/4 inch in a foot (angle 1o 47')
NPT threads are not interchangeable with NPS - National Pipe Straight - threads.
NPT threads may look similar to ISO 7/1 threads. However, ISO and NPT threads should not be mixed. ISO threads have 55o taper angle versus 60o for NPT. The NPT root and crest configurations are also different from ISO. For ISO threads pitch is usually measured in millimeters (may be expressed in Inch). The pitch are different.
The content in The Engineering ToolBox is copyrighted but can be used with NO WARRANTY or LIABILITY. Important information should always be double checked with alternative sources. All applicable national and local regulations and practices concerning this aspects must be strictly followed and adhered to.
Push sticks/blocks Save Fingers
"The true measure of a man is how he treats someone who can do him absolutely no good."
attributed to Samuel Johnson
PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.
Something happen in another thread.We've discussed this I believe in other threads.Haven't we looked for die heads for sparky.I'm almost sure Bob D. has looked em' up for us before.
I think this might be a reference to the sparky running the 3/4" diesel line for his 150KW genset (a mere toy by the way ).
"When we build let us think we build forever. Let it not be for present delight nor for present use alone. Let it be such work that our descendants will thank us for, and let us think, as we lay stone upon stone, that a time is to come when these stones will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, "See! This our fathers did for us."
John Ruskin (1819 - 1900)