Standard Duty Rigid Coupling

A rigid grooved coupling joins two grooved pipe ends so the joint behaves like a welded or flanged one: it allows no angular or linear movement once tightened. That makes it the coupling for risers, valve connections and anywhere the pipework must hold its alignment.

How it works

Two housing segments are bolted around a gasket that sits over both pipe ends. Keys on the housings engage the grooves and clamp the pipe ends; line pressure presses the gasket onto the pipe, so the seal tightens as pressure rises.

Gasket selection

The gasket material decides the service: EPDM for water, NBR (nitrile) for oils and hydrocarbons, silicone for higher temperatures. Check the fluid and temperature against the gasket before specifying.

Installation

• Check that pipe ends and grooves are clean, undamaged and to the coupling maker’s groove dimensions.
• Lubricate the gasket with a lubricant compatible with the gasket material, and seat it over both ends.
• Fit the housings with the keys in the grooves, and tighten the nuts evenly and alternately to the coupling maker’s instructions.
• Support the pipework so the fitting carries no load it was not designed for.