The outside diameter of a pipe or fitting must be measured and compared to a table for size identification. 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.What are the different types of pipe threads?
There are many different types of pipe – stainless, galvanized, black (actually iron), copper, brass, etc., but the key is the actual TYPE of thread that the fitting (or pipe) has. If the fitting/pipe has an NPT (National Pipe Thread) thread on it, you absolutely MUST use a thread sealant on it.What is PT thread?
1.The abbreviation of the NPT is National (American) Pipe Thread, belong to the American standard of 60 degrees taper Pipe threads, it main used in North America. 2.The abbreviation of PT is Pipe Thread, 55 degrees sealed tapered Pipe Thread, belongs to the family of wyeth Thread,it main used in Europe and the commonwealth countries.