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• Time of issue:2022-10-24 14:27
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(Summary description)Torque free box spanner or hammer spanner: applicable to the fastening of general equipment and pipe flanges, selected according to the bolt size and flange pressure grade. The fastening requirements are as follows: 1) The maintenance unit shall formulate the fastening scheme, tighten the flanges symmetrically, and number the fastening sequence. Refer to Figure 1 and Figure 2 for numbering. 2) Use 4 bolts to position the gasket at positions 1, 2, 3 and 4 to ensure that the center of the spiral wound gasket is within the flange edge. 3) Tighten the positioning bolts by hand, then insert other stud bolts and tighten them by hand to balance their load, and ensure that at least 2 threads are exposed at each end of the nut. 4) According to the field equipment and flanges, the fastening cycle shall be calculated once. The fastening times (at least 3 times) and the hammering load (force) for each fastening shall be reasonably determined. The fastening hammering load (force) shall be tightened from small to large (such as 50%, 80%, 100% increase). The load shall not be loaded too fast or too large to prevent gasket sealing failure. 5) Tightening sequence of torque free box wrench or hammer wrench: Tighten the two bolts that are diametrically opposite to each other to the given hammering load (force) of the bolt; Tighten another pair of bolts about 90 degrees away from the previous two bolts along the circumference; Continue tightening until all the remaining bolts are tightened to the given hammering load. 6) Finally, all bolts shall be tightened clockwise or anticlockwise according to 100% hammering load (force).