Three piece welded ball valveThe product is processed with polishing equipment both inside and outside to achieve surface precision requirements. This valve is widely used in many industries such as food, brewing, beverages, dairy products, fine chemical pharmaceuticals, and biotechnology
The operating precautions for three piece welded ball valves are as follows:
1、 Preparation before operation
Check valve status: Before operation, confirm that the valve is fully open or fully closed to avoid damage to the sealing surface caused by partial opening.
Cleaning the pipeline: Before installation, the pipeline needs to be flushed to remove residual impurities (such as welding slag and oil stains), to prevent damage to the valve seat and sphere.
• Valve testing: Before performing pressurized opening operations, an open/close test is required to confirm whether the ball valve has a diameter or reduced diameter structure that meets the requirements of the cutting tool.
2、 Operating standards
Prohibition of throttling use: Ball valves are only suitable for fully open or fully closed states and cannot be used for flow regulation.
Valve handle operation: When rotating the valve handle, sufficient space should be left to avoid valve damage caused by restricted operation.
Installation of transmission mechanism: Ball valves with transmission mechanism should be installed upright to ensure the normal operation of the actuator.
3、 Welding and maintenance
1. Welding process:
Before welding, it is necessary to clean the oxide scale and oil stains within a 20mm range of the valve body connection to expose the metallic luster.
The connection part of carbon steel/alloy steel needs to be preheated to 75-100 ℃ to prevent quenching and cracking.
The large-diameter valve body (DN300 or above) adopts a combination process of argon arc welding as the base and electric arc welding filling.
2. Online maintenance:
After loosening the valve body screws, the main valve body can be rotated to replace the valve seat sealing ring without disassembling the entire valve.
The auxiliary valve body can be retained on the pipeline to reduce maintenance workload.
4、 Special precautions
High temperature protection: During welding, the valve core should be kept fully open to avoid high temperature damage to the PTFE sealing ring.
• Deformation control: When welding multiple layers, it is necessary to use fixtures to fix the valve body and monitor changes in the spacing between positioning points in real time.
• Arc striking taboo: It is forbidden to directly strike an arc on the surface of the valve body to prevent local overheating and material performance degradation.