The splicing requirements for ASME head mainly include the following aspects:
Splicing and welding joint coefficient: In ASME specifications, the splicing and welding joint coefficient of the head depends on the qualification level of non-destructive testing. If 100% RT testing is conducted and the testing technology level is AB or III, the welding joint coefficient of the head is taken as 0.85
If the detection technology level is AB level and II level is qualified, the welding joint coefficient can be taken as 1. This method is suitable for pressure vessels made of non-ferrous metals.
Weld seam spacing requirements: According to ASME standards, the weld seam spacing on the head should meet specific requirements. Specifically, the distance between the centerlines of various non intersecting welds on the head shall not be less than three times the thickness of the steel and not less than 100mm
In addition, all splicing welds on the convex head are considered Class A joints, and special attention should be paid to the spacing requirements.
Other relevant standards: In the ASME standard, the classification and characteristics of head splicing and welding joints are also detailed. For example, Class A joints include splicing joints at the positions of spherical shells, formed heads, flat heads, etc., which can withstand the maximum principal stress; B-class joints include circumferential joints on cylinders, pipes, and conical shells, which are subjected to half the stress of A-class joints; C-type joints include joints located at flange rings, pipe plates, and other positions; D-type joints include joints that connect the connecting pipe or other pressure chamber to the main body
These classifications help to understand the specific applications and requirements of different joints.