gas collecting tube 1.Standard:ASME,DIN,GB 2.Material:15CrMo 3.Process:centrifugal casting 4.Certification:ISO9001:2008 gas collecting tube1.standard:ASME A608 ;DIN,HG/T 2601-2000;HG/T 3673-2000;GB 13296-20072.Material:alloy 15CrMo3.Size:Dia.219X12,Dia.225X24 or we can supply standard and nonstandard as your request4.Process:centrifugal casting5.Quality:appearance of smooth,can work under presure ...