(1) welded elbow materials are: carbon steel, aluminum, pipeline steel, alloy steel and stainless steel.
(2) According to the elbow point of view, there are 45 degrees welded elbow, there are 90 degrees welded elbow and 180 degrees welded elbow and other different points of view of the elbow.
(3) If divided by pressure level, there are about seventeen kinds, and the United States pipe standards are the same, there are: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140 Sch160, XXS, among which the most commonly used are STD and XS two.
(4) welded elbow according to its radius of curvature, can be divided into long-radius welded elbow and short-radius welded elbow. Long-radius welded elbow radius of curvature equal to 1.5 times the outer diameter of the tube, that is, R = 1.5 D. Short-radius welded elbow radius of curvature equal to the outer diameter of the tube, that is, R = 1 D. The formula D is the diameter of the butt weld elbow, R is the radius of curvature. If there is no special indication, the usual choice is 1.5D elbow.