Grooved Coupling Rigid Coupling

Overview

Grooved rigid couplings are mechanical pipe connectors designed to create a fixed and non-flexible joint in grooved piping systems. They are specifically used in applications where pipe alignment, rigidity, and system stability are required.
By mechanically locking into the pipe grooves, rigid couplings provide a joint performance comparable to flanged or welded connections, while maintaining the advantages of fast installation and easy maintenance.

Product Description

Grooved rigid couplings join pipes by using pre-formed or machined grooves at the pipe ends. During installation, a resilient elastomer gasket is positioned around the pipe ends, followed by two ductile iron coupling housings that engage directly into the grooves. High-strength bolts and nuts are tightened to complete the connection.

The coupling housings are engineered with integrated locking profiles that securely engage the pipe grooves. This design minimizes or eliminates angular deflection, axial movement, and rotational displacement, ensuring a stable and rigid pipeline after installation.
Grooved rigid couplings are available in sizes from 1″ to 12″, with a maximum working pressure of 300 PSI, and are FM Approved and UL Certified.

Surface finishes include red painted, galvanized, epoxy-coated blue, and grey, suitable for various environmental and project conditions.

Pressure Retention Performance

The product meets strict pressure retention standards, as detailed below:

Rubber Gaskets

Sealing performance is ensured by specialized rubber gaskets, with options tailored to different media and temperatures:

   Gasket Options

• EPDM – for water, fire protection, and general service

• Nitrile (NBR) – for oil and petroleum-based fluids

• Silicone – for elevated temperature applications

Installation Instructions

Key Features

• Rigid joint performance suitable for fixed piping systems

• Positive mechanical engagement with pipe grooves to restrict movement

• Pressure-activated sealing mechanism for reliable leak prevention

• No welding or threading required, reducing installation time and labor risk

• Multiple gasket materials available for different media and temperatures

• Certified to FM and UL standards for fire protection applications

Functions & Applications

Grooved rigid couplings are used to securely connect pipe sections where movement is not permitted, making them ideal for systems that require precise alignment and long-term stability.

They are commonly specified in automatic sprinkler systems, where industry standards recommend grooved or flanged connections, particularly for pipe diameters DN100 (4″) and above.

Typical application areas include:

• Fire sprinkler and fire fighting systems

• Mechanical rooms and pump connections

• Commercial and industrial piping networks

• HVAC and chilled water systems

• Long straight pipeline installations

FAQ

Q1: What is a rigid coupling used for?

A rigid coupling is used to connect grooved pipes with a fixed, non-flexible joint, preventing movement and maintaining pipe alignment.

Q2: How is a rigid coupling different from a flexible coupling?

Rigid couplings do not allow angular or axial movement, while flexible couplings allow limited movement to absorb vibration or thermal expansion.

Q3: What systems commonly use rigid couplings?

Rigid couplings are widely used in fire protection, HVAC, industrial piping, and mechanical equipment connections, especially in straight pipeline sections.

Q4: What gasket materials are available?

Common gasket options include EPDM (water & fire protection), Nitrile (oil service), and Silicone (high temperature).

Q5: What is the typical pressure rating?

Rigid couplings are typically rated up to 300 PSI (Class 150), depending on size and application.