Problems with the synchronous tightening sequence of four heat exchangers

Thread Content

This post was last written by chenlin_g edited on 2017-12-8 18:32 Dear friends: According to the information found on the Internet, the tightening sequence requirements of the four-synchronous hydraulic torque wrench for the heat exchanger tube box bolts are as follows: first step: Tighten to 50% of the selected torque value. As shown in Figure B.1, first tighten bolts No. 1 to No. 8 in sequence. ； Then tighten the remaining bolts No. 9 to No. 16 in sequence according to 50% of the selected torque value. Step 2: As shown in Figure 2, the interval method is used, and according to 80% of the selected torque value, tighten every other bolt starting from No. 1. Step 3: As shown in Figure 3, the sequential method is used to tighten the bolts one by one according to the set torque value of 100%. Step 4: Follow step three. I have some questions about this fastening method: 1. Why not use the same method as the first pass for the first three passes and fasten them all symmetrically? 2. In the second pass of the gap method and the third pass of the sequential method, should four wrenches be tightened at the same time, or should a single wrench be tightened? If there are any sea friends who have experience in this area, please come forward. . :lol I couldn’t post the picture in reply, so I edited the original post to see the traditional tightening steps of a single bolt as follows.: The torque is tightened symmetrically in three steps, one for confirmation, one for loosening and then tightening. Alternatives given by Quad Synchronous ASME: Utilizing the symmetrical uniformity of the four-synchronous torque wrench, the process can be completed in two steps (actually one step), which is more efficient.