Matters needing attention when installing the grooved couplings

(1) The installation quality of the clamp, especially the installation quality of the flexible clamp, depends on the above-mentioned requirements: that is, the pipe material, the shape size, the deformation of the nozzle, the quality of the pressure groove and the quality of the clamp itself, and the size is out of tolerance. , It must also be ensured that each clamp is fully inserted into the groove.

(2) Attention should be paid to the installation of large-caliber flexible couplings with DN≥300 and above:
① Inspection of the material and appearance of the rubber sealing ring: The rubber sealing ring of each manufacturer varies according to the medium used, and its manufacturing material and formula are different, but the installation unit must ask the manufacturer for the same product quality commitment and rubber as the unit’s engineering service life. The physical and mechanical performance test report of the sealing ring shall have no damage or deformation in appearance inspection. No bubbles, impurities, cracks, and uneven defects on the rubber sealing surface are allowed.

②The installation of grooved pipe fittings: a. Touch the grooves and holes by hand and observe with eyes for a week. There should be no remaining burrs, breakages, cracks, and the remaining dirt around the nozzle should be removed. b. Lubricant is spread around the rubber sealing ring and then clamped on both ends of the steel pipe by hand. At this time, it is necessary to ensure that the tension around the rubber sealing ring is basically the same. c. Two pieces of grooved pipe fittings, symmetrically tighten the bolts on both sides, so that the gap between each groove is basically equal. When it is close to tightening and not in close contact with the rubber seal ring, use both hands to rotate the grooved pipe fittings to make the entire pipe and the sealing ring evenly contacted initially. Observe that all pieces of the grooved pipe fittings have entered the groove, and then tighten the bolts symmetrically and successively. . When tightening, the sealing ring is found to be wrinkled and protruding, and the sealing ring should be replaced.

③It must be ensured that the convex edge of the grooved pipe fits into the groove before the bolts are tightened symmetrically on both sides. This “knocked-in” refers to the protrusion of about 2mm on the raised edge of the grooved pipe fittings and the height of the pipe groove about 2mm should be flush with the recessed inlay after the nozzle is pressed into the groove. The convex edge of the finished clamp sometimes appears too thick, deformed, or even twisted too much. If it can be repaired on site, it can be repaired. If it cannot be repaired, it can only be discarded and replaced with another. This requires on-site operators to observe and inspect one by one, and basically meet the requirements before installing, so as to avoid rework.
④When using imported grooved pipe fittings and domestic pipe fittings, it is necessary to know in advance what standard the products used by each manufacturer are, and pipes that match the grooved pipe fittings must be used, otherwise, due to the different standards, large-area pressure tests are likely to occur Unqualified, causing huge losses.

Post time: Jul-10-2021