Therefore, the stress concentration, residual stress and poor quality of the root gap of the welded joint of the valve body have become the weak link in the valve body structure, which has attracted the attention of the valve industry at home and abroad, but there is no relevant report to solve this problem, which has become a hidden danger of the integrity of the product structure boundary.

Blocking and drainage: when the valve is closed, the valve seats at the upstream and downstream sides block the liquid, and the accumulated substances in the valve body cavity can be discharged through the drainage device.