4.3 Threading
4.3.1 Threads shall be carefully cut by using lathes or thread-cutting machines in general.
4.3.2 For threaded pipe connections, Teflon (polytetrafluorethlene) seal type shall be used except high temperature lines exceeding 230oC (for which EVER SEAL TAPE or equivalent tape shall be used). No hemp nor paint shall be used.
4.3.3 Screwed joints which are intended to be seal welded shall be made up without any thread compound or lubricant.