Pipe End Caps
The form of the blind plate is similar, except that the blind plate can be disassembled and blocked, while the welded pipe cap cannot be disassembled. The cap includes a convex cap, a cone shell, a variable diameter section, a flat cap and a shrinking port design.
Convex tube caps include: hemispherical tube caps, oval tube caps, dish-shaped tube caps and spherical caps. From the force point of view, the hemispherical tube cap is gradually not good for the convex tube cap, but from the perspective of manufacturing difficulty, it is gradually easier to manufacture.
When splicing, the weld direction is only allowed to be radial and circumferential. Large caps may cancel this requirement in the future. The splicing distance should be required to be greater than 3δ and not less than 100mm (welding heat-affected zone is a high-stress zone, and the chemical composition in this zone will be burnt. So avoid the high-stress zone, which is related to the thickness According to practical experience, the stress attenuation length is greater than 3δ and not less than 100mm). However, refrigeration equipment is difficult to meet this requirement, and has its particularity.
For the heads formed after splicing, the splicing welds should be subjected to 100% radiographic or ultrasonic testing, and the qualification level follows the equipment shell. The final weld seam detection level and proportion are the same as the equipment shell, which is high waste.
For example: If the equipment shell is tested at 20%, III is qualified. The bulkhead splicing weld and the final weld are also qualified as III, and the weld joint coefficient is 0.85;
If the equipment shell is 100% tested, II is qualified. The bulkhead splicing weld and the final weld are also II qualified, and the weld joint coefficient is 1.
Therefore, although the bulkhead splicing is 100% tested, the qualified level is different, and it goes with the equipment shell.
The correct approach is: blanking (marking)-small boards to form large boards-forming-non-destructive testing
If it is wrong to do the inspection before molding, the quality of the product after molding cannot be guaranteed. In other words, non-destructive testing refers to the final non-destructive testing.
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