Portable flange plate welding equipment in chemical pipeline installation engineering

The invention discloses portable flange plate welding equipment in chemical pipeline installation engineering, which comprises a main body part which is constructed into a sealed cylinder with a cylindrical cavity inside; a flange fixing part and a steel pipe fixing part are arranged on the main body part; the flange fixing part comprises a cross-shaped frame fixedly arranged on the main body part in a sleeving mode, moving rods are slidably arranged on the end faces of four supporting legs of the cross-shaped frame, and limiting short columns are fixedly arranged on the end faces, close to the main body part, of the ends, away from the cross-shaped frame, of the four moving rods; the steel pipe fixing part comprises a plurality of abutting blocks arranged around the main body part in a surrounding mode, and two inclined rods are symmetrically arranged between the abutting blocks and the main body part in an inclined mode. And the main body part is provided with an air pressure control piece for synchronously