(1) The flange type can be divided into: flat welding flange, bimetal welding, butt welding flange and threaded flange according to the connection form. Bi-metal welded steel pipe is a new type of pipe material. The selection of flanges must conform to steel pipe flanges (GB9112~9131), steel butt welded seamless pipe fittings (GB/T12459), and pipe flanges are covered with PTFE. Gasket (GB/T13404) standard.
(2) If the hot-dip galvanized steel pipe is flanged, threaded flanges should be used. When the system pipeline adopts the inner wall non-corrosion pipeline, it can be connected by welding. Pipeline welding shall comply with the "Code for Construction and Acceptance of Field Equipment and Industrial Pipeline Welding Engineering".
