flat head for pressure vessel 1.Standard:ISO9001-2008 JB/T1619-2002 2.Material:mild ... steel 3.shape;flat with straight flange flat head for pressure vessel1.Material:mild steel,low alloy steel,carbon steel,stainless ... ,such as petroleum,chemical industry,boiler,pressure vessels,railway transportation,metal structure,water supply facilities and aerospace engineering,etc. flat head for pressure vessel