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What is NPT thread

2022-10-11 Page view : 6 views

NPT thread is an American standard 60 degree conical pipe thread, divided into general sealing cylindrical pipe thread and general sealing conical pipe thread, fit by “cone/cone” fit, “column/cone” fit.
We are NPT threads manufacturer.
The theoretical position of the reference plane of the American general sealing screw thread conical external thread is located perpendicular to the thread axis, and the little end (reference plane) is a reference distance (L1) from the plane;

Two, basic size:

Thread diameter D2= D2= D-0.8*P

Thread path size D1= D1= D-1.6*P

Three, cooperation mode:

Cylindrical internal thread and conical external thread to form a “column/cone” match; Conical internal thread and conical external thread form a “cone/cone” fit.

Four, tolerance

The limit deviation of the base plane axial position of the general seal taper thread is -p ~+P;

Five, thread length

The minimum effective thread length of American general sealing conical external thread is not less than the sum of the actual size of the reference distance plus the assembly allowance;

The minimum effective thread length of American general sealing thread is not less than the sum of the actual deviation of the reference plane position + the basic dimension of the reference distance + the assembly allowance;

Six, mark

Complete marking of screw threads for general sealing pipes made in the United States: thread characteristic code, thread dimension code and screw direction code;

The United States general seal taper pipe thread characteristics code :NPT

Characteristic code :NPSC for internal thread of general seal cylinder

Example: Dimension code 4, left – handed general American conical pipe thread:

Chinese standard :NPT 4-LH

American standard :4-8NPT-LH

Dimension code 3, right-handed general American cylindrical pipe thread:

Chinese standard :NPSC3