Pipe threads where pressure-tight joints are not made on the threads – Part 1: Dimensions, tolerances and designation
Requirements for thread form, dimensions, tolerances and designation for fastening pipe threads.
This International Standard, a part of the ISO 228 series, specifies the requirements for thread form, dimensions, tolerances and designation for fastening pipe threads, thread sizes 1/16 to 6 inclusive. Both internal and external threads are parallel threads, intended for the mechanical assembly of the component parts of fittings, cocks and valves, accessories, etc.
These threads are not suitable as jointing threads where a pressure-tight joint is made on the thread. If assemblies with such threads are made pressure-tight, this should be carried out by compressing two tightening surfaces outside the threads, and by interposing an appropriate seal.
History and related standards
This International Standard together with BS EN ISO 228-2:2003, supersedes BS 2779:1986 which is withdrawn.
This standard includes the cross reference: