In the process of handling the adverse feedback from customers about product leakage, we found that a considerable part of it was caused by on-site engineering installation. Now, we summarize some main precautions as follows:

1. When purchasing welded valve, pay attention to that the heat generated by welding may melt the sealing ring, so cooling measures shall be taken or the valve shall be disassembled, and then welding operation shall be carried out after taking out the sealing ring;

2. Generally, the dust on the installation site is relatively large. When disassembling the valve on site, the removed metal parts and sealing ring should be packed in a clean plastic bag and placed in a clean place. When assembling the valve, it should be ensured that the sealing ring does not adhere to small sand and other garbage, and the metal parts should not be damaged;

3. When assembling the valve on site, it is necessary to follow the steps in the instruction manual to prevent the wrong parts from being installed. The installation direction of the seal should be distinguished before installation to avoid crushing the seal;

4. After the pipeline installation is completed, the valve shall be fully flushed and cleaned to ensure that there is no foreign matter. If the flushing is not clean, it is very likely that the foreign matter will just be stuck in the sealing ring, resulting in sealing failure. The seat valve and diaphragm valve have had such problems several times;

5. In dry sealing state, it is better not to operate the valve, especially for butterfly valve with large sealing surface. The valve can be operated only after water is supplied to the pipeline or proper lubrication is given.