Fixing elements are of vital importance and indispensable in the assembly of flanged joints of industrial pipes. Correctly choosing these elements allows the reduction of leaks, possible errors and pipe misalignments.
BOLT
Made from metal with a cylindrical and elongated shape. It is threaded and has a bevel at both ends that ensures correct assembly with nuts, allowing elements to be joined and fixed.
Dimensional regulations:
-Flanges ½” – 24”: ASME B16.5 Standard.
-Flanges 26” – 60”: ASME B16.47 standard (series A and B).
Regulations and grades of materials:
-High temperature services: Regulated under ASTM A193 Gr B7, B7M, B8 Cl1, B8 Cl2, B8M Cl1, B8M Cl2, B16.
-Low temperature services: Regulated under ASTM A320 Gr L7, L7M, L43, L1, B8 Cl1, B8M Cl1, B8M Cl2.
Thread pitches:
-UNC, UNF and 8UN.
WASHER
Circular metal piece that contains a hole in the center, which allows the tightening and tension force to be distributed uniformly on the surface of the flange when generating a torque between the bolts and nuts, avoiding damage to the flange.
Common materials:
-ASTM F436, SS304, SS316L, SS317L, SS321, SS347, Monel.
NUT
Hexagonal metal element that contains a hole inside, beveled and internally threaded, allowing correct assembly with bolts.
Dimensional regulations:
-Flanges ½” – 24”: ASME B16.5 Standard.
-Flanges 26” – 60”: ASME B16.47 standard (series A and B).
Regulations and grades of materials:
-ASTM A194 Gr 2H, 2HM, 7, 8, 8M.
TYPICAL ASSEMBLY
Generally when assembling a flanged joint, the fixing elements are as crucial as the choice of the ideal gasket; For each bolt, two nuts and preferably two washers are used to distribute the tightening load on the flanges evenly.