1.1 This standard specifies the dimension, tolerance, technical requirements, inspection, test, mark and package of butt welding seamless pipe fittings ( including elbows, reducing pipes, Three Direct Links and pipe caps) manufactured of carbon steel, alloy steel and austenitic stainless steel.
1.2 This standard is applicable to Steel Butt-welding Seamless Pipe Fittings manufactured by steel with nominal diameter DN 15 ~ 600 for pipelines of petrochemical enterprises.