We certainly have seen all-welded ball valve body, all know that the welding joints are generally designed for narrow gap thick-walled submerged arc welding, there is the most welded body of large-thickness tubular welded joints. We certainly want to know why this is right? 1: heat treatment technology Multi-layer thick-walled multi-layer welding process is repeated heating and cooling of the metal material process, resulting in welded joints of the organization of non-uniformity and poor quality, resulting in higher residual stress, and even weld defects. Welding is the final assembly of the product after the process, the valve cavity with non-metallic rubber seal material and PTFE plastic, can not be post-weld heat treatment. 2: joint treatment In the body welded joint design, for alignment and positioning, there is a ring in the weld root assembly of the gap, the gap in the internal pressure and external load will produce several times the normal working stress dry The stress concentration also makes it hard for engineers to deal with it. Valve body welded joints at the root of the gap stress concentration, residual stress, poor organization become the weak link in the valve body structure for the valve industry at home and abroad attention, but there is no any report to solve this problem, to become the product A hidden danger of the integrity of structural boundaries.
Plastic bags for nuts packaging
Nuts Packaging,Nuts Packaging Bags,Cashew Zipper Bag,Plastic Zipper Pouch
ZHEJIANG GONFOR SOFT-PACKAGE CO.,LTD , https://www.chinasoftpackage.com