This standard specifies the designation and fixes the dimensions and tolerances of pipe threads for non-seal coupling on the thread. These threads are applied to the mechanical unions of fittings, taps, accessories, etc. If such unions need to be made watertight, this can be achieved by tightening two sealing surfaces outside the threaded part, possibly inserting appropriate sealing material. UNI ISO 228 Part 2" considers the control of these threads. For pipe threads for tight fit on the thread, see UNI ISO 7 Part 1*. 7
UNI ISO 228-P1:1983 history
1983UNI ISO 228-P1:1983 Pipe threads for non-threaded sealing connections. Name, size and deviation