When connecting pipes using grooved couplings, specific installation procedures must be followed. The following outlines the connection steps: Ensure the pipe ends are cut cleanly and any burrs are ground smooth using a grinding wheel.
Inspect the pipe ends: the area from the pipe end to the groove must be free of nicks, protrusions, or roller marks to ensure a leak-proof seal. Before roll-grooving, adjust the limiting device based on the pipe size and required groove depth to ensure the resulting groove falls within specified limits; readjustments are necessary if the pipe specifications change.
During roll-grooving, keep the pipe end firmly against the machine's rollers and use a level to ensure the pipe remains horizontal. Use a vernier caliper and a specialized pipe OD (outer diameter) gauge to verify the groove width, depth, and outer diameter; the processed dimensions must comply with the coupling manufacturer's technical specifications. Key installation points for grooved couplings:
1. Follow an orderly installation sequence: install large-diameter pipes, main lines, and vertical risers first, followed by small-diameter pipes and branch lines.
2. Check the gasket's color coding to ensure it meets design requirements regarding temperature, medium, and service life. Lubricate the gasket's inner flange and outer surface; slide the gasket onto one pipe end, align the second pipe, and position the gasket over the joint, ensuring neither side of the gasket protrudes into the pipe grooves.
3. Leave a gap of approximately 2mm between the pipe ends and align the center axes of both pipes.
4. Verify that the coupling's internal ridge is fully seated within the grooves and lightly tighten the bolts. Then, slightly lift the upper pipe so the inner side of the coupling ridge presses against the groove wall closest to the pipe end before fully tightening the bolts; apply even force during tightening. After tightening, ensure there is no misalignment between the two halves of the coupling.
5. During the installation of the pipe clamps, visually inspect the rubber sealing ring to ensure it is seated smoothly and correctly, preventing any wrinkling. 6. Pipe supports, hangers, and sway braces must be installed and secured firmly.