What is the standard of flange welding for pipeline

　　For details, refer to hg20605-97 steel flange welding standards, which standards do you need to match? There are GB / t9119-2000 plate flat welding flange standards, Hg / t20615-97, etc. in general operation, the pipe should be inserted into the flange, which is about 3 / 1 of the flange thickness. The method of not inserting the flange is to leave a gap of 1-3mm between the flange and the pipe for welding.

　　1. Select the appropriate flange material for the pipe material, such as stainless steel pipe is definitely not allowed to select carbon steel flange;

　　2. Select the appropriate flange according to the nominal diameter of the pipeline and the nominal pressure of each section of the whole pipeline system. At present, the American Standard System and the European standard system are basically adopted in the international pipeline flange;

　　3. Select the flange structure form according to the specific working conditions: such as flat welding with neck, looper flange, etc., the sealing surface form includes convex surface, full plane, concave convex surface, etc.

　　4. Non standard parts shall be designed and manufactured according to flange specification design procedure