Slip-on threaded joints having pipe threads where pressure-tight joints are made on the threads with
parallel or tapered threads, shall comply with requirements of a recognized national or international standard.
Slip-on threaded joints may be used for outside diameters as stated below except for piping systems conveying
toxic or flammable media or services where fatigue, severe erosion or crevice corrosion is expected to occur.
Threaded joints in CO2 systems shall be allowed only inside protected spaces and in CO2 cylinder rooms.
Threaded joints for direct connectors of pipe lengths with tapered thread shall be allowed for:
— Class I, outside diameter not more than 33.7 mm
— Class II and Class III, outside diameter not more than 60.3 mm.
Threaded joints with parallel thread shall be allowed for Class III, outside diameter not more than 60.3 mm.