Alloy Steel Buttweld Fittings

pipe fitting is defined as a part used in a piping system, for changing direction, branching or for change of pipe diameter, and which is mechanically joined to the system. There are many different types of fittings and they are the same in all sizes and schedules as the pipe.

Fittings are divided into three groups:

  • Buttweld (BW) fittings whose dimensions, dimensional tolerances et cetera are defined in the ASME B16.9 standards. Light-weight corrosion resistant fittings are made to MSS SP43.
  • Socket Weld (SW) fittings Class 3000, 6000, 9000 are defined in the ASME B16.11 standards.
  • Threaded (THD), screwed fittings Class 2000, 3000, 6000 are defined in the ASME B16.11 standards.

Alloy Steel Pipe Specification

Standard : ASTM, ASME, API

Size : 1/8″ ~ 48″

Schedule : Sch 5S, Sch 10S, Sch 40S, Sch 20, Sch 20, Sch STD, Sch 40, Sch 80, Sch 100, Sch 120, Sch 160, Sch XS, Sch XXS, All Sch

Grades : ASTM A234 WP – P5, P9, P11, P12, P21, P22, P91

Type : seamless, Welded, Fabricated

Chemical Composition

UNS Designation A234
Carbon 0.05-0.2
Manganese 0.30–0.8
Phosphorus <=0.030
Sulfur <=0.030
Silicon 0.50-1.00
Chromium 1.00-1.50
Molybdenum 0.44-0.65

Mechanical Properties SS 904 L BW Fittings

Tensile strength(min) 415 ~ 585 Mpa
Yield strength(min) >= 205 Mpa
Elongation >=20%