HG/T 21631-1990 (English Version) PDF

Scope: This standard applies to pipe fittings with longitudinal welds made of carbon steel, low alloy steel and austenitic stainless steel plates, including tees (equal diameter and reducing diameter), elbows (short radius 90° and long radius 90°, 45°), three types of reducers (concentric and eccentric); divided into two series: I and II. According to the current needs and manufacturing possibilities in the production of pipes, the diameter range of three types of pipe fittings has been determined: the nominal diameters of the equal-diameter (reducing) tee main pipe, elbow, and the big end of the reducing pipe range from 300 to 1000mm (12″ ~40″), the nominal diameter of the reducing tee branch and the small end of the reducer is from 150 to 900mm (6″ to 38″). The thick and thick series of pipe fittings are listed in Table A1 and Table A2 in Appendix A for reference by manufacturers and users. The units used in this standard are: length in mm and pressure in MPa.

HG/T 21631-1990 history