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Global Leaders in Flexible Couplings, Drainage & Plumbing Systems

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Clamps and Bolts

Clamping Mechanisms for Flexseal Couplings

Bolt Clamp web

Bolted clamp

Four types of stainless steel clamp bands are used throughout the Flexseal product ranges. Stronger clamps are required as the coupling diameter increases.

Worm Drive Clamps

Worm drive mechanisms are used with two types of clamp and have fully perforated bands to allow self cleaning of any debris present on the clamps. These two types of clamps are classed as medium and high duty clamps. Medium duty clamps are used for tightening torques of 6Nm. The high duty clamps are used when higher tightening torques are required and work at 10Nm and 13Nm.

Bolted Clamps

The third type of clamp replaces the worm drive with an M8 bolt and these are used on smaller diameter couplings requiring higher hydrostatic performance. A suitable lubricant is used on the bolt to reduce friction and increase the screw efficiency and also to prevent galling associated with stainless steel. These can be tightened up to 20Nm. These are used on small diameter Magnum Couplings.

The fourth type is a unique M8 T-Bolt mechanism designed by the Fernco Group for use with larger couplings. This provides a more robust and efficient mechanism that can be easily assembled and tightened on site. These clamping mechanisms are fitted to all Large Diameter Couplings and Magnum Couplings 600mm and above. They are utilised at 20Nm and 25Nm.

This design sets the bolt at a tangent to the coupling; optimising the conversion of the applied torque to tension in the band and so maximising the contact pressure between the seal and the pipe surface.

Both anchor points for the bolt are circular and their ability to rotate gives perfect alignment of the bolt as the clamp band is tightened.

All housing components are manufactured from Grade 1.4401 (316) stainless steel and the bolt thread is lubricated with grease that both reduces friction in the thread and prevents galling between the nut and the bolt. (This phenomenon is a characteristic of stainless materials).

All couplings are supplied with a suitable spanner that can be used with standard 3/8” square drive tools

Torque Table

Coupling Torque Coupling Sizes Torque (Nm)
Standard Couplings SC65 - SC200 6Nm
  SC215 - SC385 10Nm
  SC395 - SC620 13Nm
Extra Wide Couplings SC225W - SC385W 10Nm
  SC395W - SC620W 13Nm
Large Diameter Couplings LC600 - LC900 20Nm
  LC1000+ 25Nm
Extra Wide Large Diameter Couplings LC600W - LC900W 20Nm
  LC1000W 25Nm
Magnum Couplings MAG300 - MAG400 13Nm
  MAG500 - MAG900 20Nm
  MAG1000+ 25Nm
Wraparound Couplings - 190mm Wide WRC300 10Nm
  WRC400 - WRC500 13Nm
  WRC600 - WRC900 20Nm
  WRC1000+ 25Nm
Wraparound Couplings - 370mm Wide MAGWRC300 - MAGWRC400 13Nm
  MAGWRC500 - MAGWRC900 20Nm
  MAGWRC1000+ 25Nm
Drain Couplings DC50 - DC250 6Nm
  DC275 10Nm
Adaptor Couplings Up to AC2756 6Nm
  AC9001 - AC4209 10Nm
Plumbing Couplings All Sizes 6Nm