NPT, PT, G are all pipe threads.
NPT is the abbreviation of National (American) Pipe Thread, which belongs to the American standard 60 degree taper pipe thread used in North America.
PT is the abbreviation of Pipe Thread, which is a 55-degree sealed conical pipe thread, which belongs to Whitworth thread family and is mostly used in Europe and the Commonwealth of Nations. Commonly used in water and gas pipe industry, the taper is specified as 1:16.
G is a 55 degree non-threaded sealing pipe thread, which belongs to Whitworth thread family. Marked as G stands for cylindrical thread.
In addition, the 1/4, 1/2, and 1/8 marks in thread refers to the diameter of the pipe in inches. Insiders usually refer to thread size in cents, 1 inch equals 8 cents, 1/4 inch equals 2 cents, and so on.
G is the general name for pipe threads, and the division of 55 and 60 degrees is functional, commonly known as pipe circle. That is, the thread is machined from a cylindrical surface.
ZG is commonly known as pipe cone, that is, the thread is processed by a conical surface, and the general water pipe joint is like this.
Rc means conical internal thread, ZG means taper pipe thread, 3/4" means inch mark, which is 3/4 inch conical pipe thread, the national standard stipulates that the major diameter of ZG 3/4" thread is 26.44 mm. Its representation should be: ZG 3/4″. where (〃) is the symbol for inches. An inch is equal to 8 cents. The origin of 3/4 is 6/8=3/4. Commonly known as 6 points.
The same ZG 1/2″ thread major diameter ≈ 21mm. Commonly known as 4 points. ZG 1″ thread major diameter ≈ 33mm. Commonly known as 1 inch. ZG 1 1/2″ threaded tube OD ≈ 48mm. Commonly known as 1 inch and a half.
Tapered pipe threads are very similar to pipe threads, the only difference is the taper. Note that the basic dimensions for distinguishing pipe threads from ordinary threads are different.
DN is the nominal diameter
