Cap

Process flow

Steel plate – cutting – heat treatment – processing groove – finished product – non-destructive testing – qualified products – packaging – storage and transportation (in simple terms, it is cutting (marking) – small plates are assembled into large plates – forming – non-destructive testing).

Non-destructive testing must be carried out after forming, which is the final non-destructive testing, and cannot be carried out before forming.

The forming of the pipe cap is relatively simple, usually stamping, using an outer die ring and an inner die. The shape of the inner die determines the shape of the pipe cap, and the steel plate after cutting is formed by cold pressing or hot pressing.

Application: water, beverages, beer, food, petrochemicals, nuclear power, machinery, medical equipment, fertilizers, shipbuilding, waterproofing, pipelines, etc.

Avoid splicing at the r of the disc-shaped pipe cap, which will reduce thinning and high stress.

When splicing, the weld direction requirements are only allowed to be radial and circumferential. The distance of splicing should be greater than 3δ and not less than 100mm (the heat affected zone of welding is a high stress zone, and the chemical composition in this zone will be burned. Therefore, the high stress zone should be avoided, which is related to the thickness. According to practical experience, the stress attenuation length is greater than 3δ and not less than 100mm). However, it is difficult for refrigeration equipment to meet this requirement, which has its own particularity.

After splicing, the weld seams of the formed heads should be 100% tested by radiography or ultrasonic testing, and the qualified level should follow the equipment shell. The inspection level and proportion of the weld seams formed at the end are the same as those of the equipment shell, which is high and wasteful.