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ADD:Changfeng Industry Zone 
Pingshui Town  Shaoxing


Give full play to the advantages of network meetings, and strengthen the safety line of epidemic prevention and control

At present, the overall situation of epidemic prevention and control in Shanghai is stable and good. In accordance with the relevant requirements for epidemic prevention and control of the city and district, in order to ensure that the epidemic prevention net is firmly woven, the fifth general meeting of the second session of Shanghai Fastener Industry Association was held in the form of network at 8:00 a.m. on September 19, 2022. This meeting was held under the influence of the epidemic in the second quarter, when our fastener staff actively resumed production and tried to reduce the economic losses caused by the epidemic. During the two-day general meeting, everyone squeezed time out of their busy schedule, actively participated in the meeting, seriously participated in the discussion of the meeting topics, actively communicated and gave feedback, and successfully completed the various topics of the general meeting. The meeting listened to and reviewed and approved the work report of the second council of Shanghai Fastener Industry Association to the fifth session of the second general meeting and the report on the financial revenue and expenditure audit of the council in 2021.

Fastener market size

Fasteners are widely used as basic mechanical components, known as the "rice of industry". They are widely used in automobile, energy, electronics, electrical appliances, machinery and other industries, characterized by a wide variety of specifications. With the rapid development of China's machinery industry, automobile industry and other industries, the demand and production of fasteners have been driven. In 2021, the economy will continue to recover steadily, the production demand will continue to rise, the market players are expected to be better, the economic development will show a steady and good trend, the growth of infrastructure investment is expected to accelerate, and the demand for fasteners in related industries will gradually recover.

Inspection of flange fasteners

Gasket: during installation, ensure that the gasket is new, clean and dry, and check whether the gasket is defective and damaged; Old gaskets cannot be reused; Before installation, confirm that the gasket size and grade used are consistent with the flange identification. Flange: before installation, check whether the flange surface is damaged, such as scratches, nicks, mud, corrosion and burrs. If the depth of the dents and scratches that cross the water lines of the flange sealing surface radially exceeds 0.2mm, and the coverage exceeds half the width of the gasket sealing surface, the flange must be replaced or the sealing surface must be reworked and repaired; The bearing surface of the nut on the back of the flange shall be parallel and smooth; Check whether the flange is aligned, and the inspection method shall comply with the requirements of 6.2 pipeline installation in SH3501-2011. Bolts and nuts: check whether the bolts and nuts are used correctly according to the design requirements of equipment and pipes; The thread and contact surface shall be free of dirt, rust, double skin, nick, burr, debris and other external substances that may affect the torque during fastening; It is not allowed to repair bolts by welding or machining; After the flange is installed and fastened, at least two threads are exposed outside the nut; The bolts and nuts must be lubricated before use to make the bolts have low friction coefficient and improve the anti sliding wire and corrosion resistance of bolts and nuts; Stud threads, nut threads and contact surfaces must be degreased and dried before applying lubricating oil; Unified lubricating oil shall be properly used for bolt threads, nut threads, nut bearing surfaces, washers, and nut bearing surfaces on flanges; Use high temperature anti seize compound as required.

Bolt fastening method

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).

The steel PMI in July showed that the contraction of steel supply and demand at both ends of the industry continued to slow down

According to the PMI of the steel industry investigated and released by the Iron and Steel Logistics Committee of the China Union of Things, it will be 33.0% in July 2022, down 3.2 percentage points month on month. The operation of the steel industry
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Changfeng Industry Zone Pingshui Town Shaoxing

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