Requirements for the alignment accuracy of diaphragm couplings
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What is the typical requirement for the axial (end-face) alignment accuracy of diaphragm couplings with a diameter of 200 mm? Where can I find relevant standards? Thank you!
The fit tolerance between coupling half A and the shaft is H7/js6. The axial clearance between the two end faces of a B-type coupling is generally 2-6 mm. When installing a toothed coupling in C, it should be ensured that the outer teeth are located in the middle of the width of the inner teeth. When installing an elastic cylindrical pin coupling, the elastic ring and the pin should be in an interference fit with a certain degree of tension; the diameter clearance between the elastic ring and the coupling pin hole should be 0.6–1.2 mm. The alignment requirements for E-type couplings shall meet the specifications in Table 2: Alignment Requirements Table for Couplings. Coupling type: Radial tolerance; End face tolerance; Stiffness – 0.06; 0.04. Elastic cylindrical pin type: 0.08; 0.06. Gear type: 0.08; 0.06. Laminated type: 0.15; 0.08. When checking the alignment of F-type couplings, no more than 4 shims per set may be used. After the G hot oil pump has been preheated to the proper temperature, the alignment of the coupling should be checked. Perform a macroscopic inspection of the H-stack coupling.
Radial Axial Disc 0.15 0.10 Between couplings Positive and negative 0.15 Unit (mm)
Our unit also uses 200mm diaphragm couplings; why is the alignment accuracy required to be so high? 0.04mm radially and 0.02mm axially (turbine – compressor)
The standard value is 0.10 mm axially and 0.15 mm radially. Generally, the alignment of couplings is subject to standard requirements set by pump manufacturers.
Maintenance and Repair Procedures for Petrochemical Equipment