The core working principle of grooved couplings is to achieve a reliable pipe connection through a "triple-engagement self-tightening seal." This process can be broken down into the following components:
Basic Structural Composition
It consists of three parts: an inner sealing rubber gasket, an external coupling housing, and locking bolts. The rubber gasket is fitted over the ends of the two pipes to be connected, the coupling housing is placed around the gasket, and the assembly is securely fastened to the pipes using the bolts.
Groove Engagement and Positioning
Standard circumferential grooves are pre-formed at the pipe ends using a roll-grooving machine. The inner rim of the coupling fits precisely into these grooves, axially positioning the pipes to prevent axial shifting without damaging the original anti-corrosion coating on the pipe's inner wall.
Self-Tightening Sealing Mechanism
The rubber gasket is sized slightly larger than the cavity formed between the coupling and the pipes; tightening the bolts provides initial compression for a basic seal. When internal fluid pressure rises, the pressure further compresses the gasket against both the inner wall of the coupling and the outer wall of the pipe. This creates a self-tightening sealing effect that intensifies as pressure increases, significantly enhancing leak resistance under high-pressure conditions.