What Causes Cracks In Stainless Steel Ball Valves During Welding?

3 Piece Ball Valve is mainly used in pipelines to cut off, distribute and change the flow direction of the medium. It only needs to rotate 90° and a very small torque to close tightly. Ball valves are suitable for use as switches and cut-off valves.

Since ball valves usually use rubber, nylon and polytetrafluoroethylene as valve seat sealing ring materials, their operating temperature is limited by the valve seat sealing ring material. The cut-off effect of the ball valve is achieved by the metal ball being pressed against the plastic valve seat under the action of the medium (floating ball valve). The valve seat sealing ring undergoes elastic-plastic deformation in local areas under the contact pressure. This deformation can compensate for the manufacturing accuracy and surface roughness of the ball and ensure the sealing performance of the ball valve.

Stainless steel ball valves can be installed in various ways, such as clamping, flange, thread, and welding. Depending on the use environment and considerations, you can choose the valve connection method.

Some conditions that may occur when welding stainless steel ball valves. When welding stainless steel ball valves, we must remember our choice. If we choose the national standard for wcb, it is A3 or other high manganese and high carbon iron elements that are easy to burst during welding. Or during welding, the valve body will break or have obvious cracks. For stainless steel ball valves, we should choose 304 or 304 or above. This can ensure the safety of the valve during welding and the stable and safe use in the later stage.

What causes cracks when stainless steel ball valves are welded?

1. It is due to the high welding current. Or argon arc welding is not selected, so that the stainless steel changes the intergranular density at a higher temperature and cracks appear;

2. The material problem of the valve body itself. Due to the high carbon content of the valve body, when welding, the hardness is high, and the stainless steel will crack once it is subjected to high temperature.

Therefore, when choosing a stainless steel ball valve, you should avoid cracks or quality problems. You should choose a manufacturer with integrity and must use 304 materials that meet national standards. And you must bring a material quality certificate.