Grooved Eccentric Reducer

A grooved eccentric reducer joins two grooved pipes of different sizes with one side of the fitting flat. On pump suction lines it is normally installed flat side up, so that no air pocket can collect at the top of the reducer and reach the pump.

How a grooved joint works

Each end of the fitting carries a groove. It is joined to grooved pipe or another fitting with a grooved coupling: two housing segments bolted around a gasket, with keys on the housings that engage the grooves. Line pressure presses the gasket against the pipe, so the seal tightens as pressure rises.

Joints are made without welding or threading on site, and a section can be taken apart for maintenance and put back without cutting.

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.