Hardware for the installation of offshore oil & gas
and wind turbine structures

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CRUX Heavy Duty Diaphragm Closures

CRUX 'Heavy Duty' Diaphragm Closures as required for the provision of auxiliary buoyancy, are made from rubber with fabric reinforcement. Fixing is achieved by clamping a solid core, around which the laminations of reinforcing fabric are wrapped, between two machined flanges.

The required Diaphragm strength for specified application is achieved by provision of appropriate fabric strength and number of plies.

Crux 'Heavy Duty' Diaphragms are unique in that they are manufactured with one side of the Diaphragm flat. The Diaphragm is then deformed to fit into the fixing grooves within the flanges by torquing the fixing bolts. This forced deformation of the Diaphragm ensures that a seal is obtained, even at early stages of bolt torquing. Tolerance to flange distortion resulting from welding is much better than with other competitor diaphragms.

Flanges are constructed from steel material EN10025 Grade S275 (ASTM A36) or equivalent. High strength steel can be used where strength requirement or client specification dictates. All bolts and nuts used are zinc plated according toBS3692 Grade 8.8.

Crux Heavy Duty Diaphragms command the largest share of the worldwide market.

Heavy Duty Diaphragm Closures

Internal Diaphragm Closures

Heavy Duty Diaphragm Closures
Heavy Duty Diaphragm Closures

Other features of the Crux Diaphragms

  • Flanges are shaped to avoid stress concentrations within the Diaphragm.
  • Diaphragms are designed to suit specific platform requirements and generally tested to 1.5 times the calculated hydrostatic pressure.
PILE SIZE DIMENSIONS in mm BOLT SIZES
in inches A B C number and (mm)
24 854 660 66 16 x 16
30 1184 980 66 20 x 16
36 1344 1130 70 24 x 16
42 1504 1290 70 24 x 16
48 1656 1432 80 30 x 16
54 1838 1614 80 30 x 16
60 2030 1758 80 36 x 20
66 2194 1928 100 36 x 20
72 2314 2070 100 42 x 20
84 2564 2320 100 42 x 24
96 2804 2534 100 48 x 24

NOTE: Pile sizes are compatible with Grout Seals as noted. Diaphragm dimensions will vary according to actual member sizes and individual project requirement.

Internal Diaphragms Closures are provided where there can be no external projection on the subject tubular. The Diaphragm specification is as above but the fixing is provided in the form of two rings.