Technical measures for the reconstruction of the n

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Technical measures for the construction of spherical tank nozzle renovation

x Co., Ltd. stopped on February 20, 2001. This renovation involves the renovation of 10 spherical tank nozzles. The relevant parameters of the 10 spherical tanks are shown in Table 1 below; Among them, the flanges of 3 spherical tanks are replaced and the holes of 10 spherical tanks are blocked, as shown in Table 2

2 assemble the processed plug plate at the inner end of the nozzle of the plug hole (confirm that the nozzle is consistent with the drawing before assembly). See the drawing for details

3 welding: the welding process is as follows:

4 inspection: Dye detection is carried out 24 hours after welding, and jb4730-94 grade I is qualified

5 visible pressure test: use the pressure test blind plate and reifenhuser thought it would take 6 years to blind the pipe plugging flange, and conduct the tightness test. The test pressure: pt=2.21mpa; PT=0.68MPa; PT=0.38MPa; PT=1MPa.。

6 hole sealing: after the pressure test is qualified, remove the pressure test flange, replace the formal blind plate (without gasket) and tighten the bolts

7 hot work is not allowed in the base metal of spherical shell and non welding area during construction

3.1.2 nozzle replacement flange

1 determine to replace the nozzle flange according to the requirements of the drawing, and cut it according to the requirements of the drawing

2 cut along the scribed position and use φ 100 fire resistance test method for doors and rolling shutters GB 7633 (8) 7 grinding machine and rod grinder grinding groove, slope can be analyzed in detail 1. See the figure below for the lower mouth type

3 for the welded junction between the connecting pipe and the new flange, the flange surface is required to be horizontal, with a tolerance of 1% DG and < 3mm

4 welding according to the following process

7, add a pressure test blind plate on the flange side of the nozzle, and conduct a local pressure test on the nozzle. The pneumatic test pressure: tag No. u-fb103a, B, C, p=2.04mpa

8 after the pressure test is qualified, cut off the internal blind plate of the connecting pipe, first use the carbon arc air gouging to scrape off the fillet weld meat, then use the grinder to polish the welded junction, separate the blind plate from the connecting pipe, and then grind the base metal of the connecting pipe too smoothly

during construction, hot work is not allowed in the spherical shell base metal and non welding area

1 welding rod: obtain the welding rod according to the welding rod model on the welding process instruction. The welding rods used must have factory certificates. The welding rods shall be dried and insulated according to the pressure vessel quality assurance manual before use, and there shall be no coating falling off

2 pressure vessel welding welders must pass the examination in accordance with the "boiler and pressure vessel welder examination rules". And there are corresponding welding positions

3 welding environment: in case of any of the following conditions in the welding environment, effective protective measures must be taken, otherwise welding is prohibited

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