This utility model provides a fixture for testing the airtightness of irregular flanges, including a support platform, with a base fixedly connected to the surface of the support platform; a
piston rod fixedly connected to the center of the bottom surface of the base, and the
piston rod slidably connected inside a cylinder; a fixing plate fixedly connected to the top of the cylinder; multiple
grippers rotatably connected to the surface of the fixing plate; multiple clamping plates installed on the side walls of the base, with the
grippers slidably connected to the side walls of the clamping plates; a rubber sleeve installed on the surface of the base, with multiple positioning pins installed on the surface of the rubber sleeve; the positioning pins engage the irregular
flange, the irregular
flange is placed on the surface of the rubber sleeve, and the
grippers abut and compress the side walls of the irregular
flange. The fixture for testing the airtightness of irregular flanges provided by this utility model has the advantages of quickly fixing the flange and ensuring the sealing of the connection.