Welded insulated cylinders i a type of high vacuum drawn, multilayer heat inulating removable cryogenic liquid vesel which can be applied to store, transport the liquefied gas products(liquefied oxygen, liquefied argon, liquefied nitrogen, liquefied carbon dioxide and N2O if charged by the high pressure cryogenic cylinders)BTIC ue the advanced technique and echnology and the whole production proces is carried out under the trict quality-guaranty ystem control, so the quality of the cylinders can be effectively guaranteed with characteritics of safety, reliability, convenience in operation, high capacity of gas charging and refilling ability. Since BTIC's welded insulated cylinder ha been developed, it has received technology award, Beijing famous brand award, and obtain US DOT approval and Canadian TC approval.