Technical treatment of full welded ball valve body

All welded ball valve body, welded joints are generally designed for narrow gap thick wall submerged arc welding, the valve body is mostly thick cylinder welded joints. There are two main reasons:

1: joint processing

In the body design of welding joints, for alignment and positioning assembly, there is a circular slot in the weld root, the gap in the internal pressure and the external loads will produce a few times do normal work stress concentration, also enable engineers to deal with.

The valve body welding joint root gap stress concentration, residual stress, poor organization becomes a weak link in the structure of the valve body, valve for attention at home and abroad, but there is no related report this problem to any solution, become a hidden danger of this product structure boundary integrity.

2: Heat Treatment Technology

The thick wall multi layer welding process is the process of repeated heating and cooling of the metal material, which leads to the inhomogeneity and the inferior quality of the welded joint. Welding is the last process after the assembly of the sanitary ball valve, the valve cavity with non-metallic sealing material rubber and PTFE plastic, can not be carried out after welding heat treatment.