BS EN 10253-4 Butt-welding pipe fittings Part 4:Wrought austenitic and austenitic-ferritic （duplex）stainless steels with specific inspection requirements you may also check non standard sizes pipe fitting weight online calculation, pipe fitting surface area online calculation,pipe fitting surface volume online calculation from our pipeline tool link: https://alloypipefitting.com/fitting-calculator.html For the pipe fitting material, please check butt-weld-fitting-standard-data 1.1