Abstract： ASME B31.4:2016 pdf download.Pipeline Transportation Systems for Liquids and Slurries. (a) Smoothly contoured wrought tees or crosses of proven design or integrally reinforced extruded headers are preferred. When such tees, crosses, or head...

ASME B31.4:2016 pdf download.Pipeline Transportation Systems for Liquids and Slurries.

(a) Smoothly contoured wrought tees or crosses of proven design or integrally reinforced extruded headers are preferred. When such tees, crosses, or headers are not used, the reinforcing member shall extend completely around the circumference of the header

(see Fig. 404.3.4-1 for typical constructions). Whenever possi. ble, the inside edges of the finished opening shall be rounded to a in. (3 mm) radius. If the encircling member is thicker than the header and its ends are to be welded to the header, the ends shall be chamfered (at approximately 45 deg) down to a thickness not in excess of the header thickness, and continuous fillet welds

shall be made. Pads, partial saddles, or other types of localized reinforcements are prohibited.

(b) The reinforcement member may be of the complete encirclement type (see Fig. 04.3.4—fl, pad or saddle type

(see Fig. 404.3.4-2), or welding outlet fitting type. Where attached to the header by fillet welding, the edges of the

reinforcement member shall be chamfered (at approximately 45 deg) down to a thickness not in excess of the header thickness. The

diameter of the hole cut in the header pipe for a branch connection shall not exceed the outside diameter of the branch connection by more than ‘4 in. (6.4 mm).

(C) Reinforcement for branch connections with hole cut NPS 2 or smaller is not required (see Fig. 404.3.4-3 for typical details);

however, care shall be taken to provide suitable protection against vibrations and other external forces to which these small

branch connections are frequently subjected.

(d) Reinforcement of opening is not mandatory; however, reinforcement may be required for cases involving pressure over 100 psi

(7 bar), thin wall pipe, or severe external loads.

(e) If a reinforcement member is required, and the branch diameter is such that a localized typeof reinforcement member would

extend around more than half the circumference of the header, then a complete encirclement type of reinforcement member shall be

used, regardless of the design hoop stress, or a smoothly contoured wrought steel tee or cross of proven design or extruded header may be used.

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