... , double socket, Flange elbow , reduce elbow, sat elbow, inside and outside teeth, stamping bend , push elbow, socket elbow, butt welded elbow, inner elbow Thickness SCH20, SGP, STD ... B2312 JIS B2313Certificate: ISO9000:2000 , API, CEElbow classification : reducing elbow, long radius elbow short radius elbowCARBON STEEL : ASTM A234 WPB, WPC; ASTM A420 ...