Stainless steel caps in English (Stainless steel caps), also known as plugs or heads. Use: welded to the end of the pipe or mounted on the pipe end of the external threads to cover the pipe fittings. Used to close the pipeline, the role of the same with the plug.
The cap includes convex cap, cone shell, reducer section, flat cap and tight mouth design.
Convex caps include: hemispherical caps, oval caps, disk-shaped caps and crown-shaped caps. From the point of view of the force convex pipe cap from the hemispherical pipe cap gradually bad, but from the manufacturing difficulty, gradually good manufacturing.
Stainless steel: 304 304L 316 316L 321 2520 310, 317, and other materials.
:DN15-DN1200 through diameter
Wall thickness: SCH5-SCH160
Standard: ASME DIN JIS BS GB/T JB SH HG
Application: water, beverages, beer, food, petrochemicals, nuclear power, machinery, medical equipment, fertilizers, shipbuilding, waterproofing, treatment, piping, etc.
Packing: wooden case, carton service: provide technical advice, guidance for installation, etc.
Disc-shaped pipe cap at the r to avoid splicing, will be thinning, high stress.
Splicing when the weld direction requirements are only allowed to be radial and circumferential. Later large caps may cancel this requirement. Splicing distance should be required for more than 3 δ, and not less than 100mm (welding heat-affected zone is a high stress area, and the chemical composition in the area will have burned. So avoid the high stress zone, the area 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, has its own special characteristics.
Splicing after molding of the head, splicing weld should be 100% ray or ultrasonic testing, qualified level with the equipment shell away. The final molding of the weld detection level, the proportion of the same with the equipment shell, high waste.
Example: If the equipment shell is 20% testing, III qualified. That boring head splicing weld and the final weld is also III qualified, welded joints coefficient of 0.85;
If the equipment shell is 100% testing, II qualified. Then the boring head splicing weld and the final weld is also II qualified, welded joint coefficient of 1
So boring head splicing although 100% testing, but the level of qualification is not the same, with the equipment shell to go.
But pay attention to the manufacturing process:
The correct approach is: material (scribing) - small plate into a large plate - molding - non-destructive testing
If not before the molding to do the test is not right, there is no guarantee that after the molding is still qualified. In other words, NDT is the final NDT.