1. Precautions
Valves are pipeline components designed to open or close circuits, control flow direction, and regulate parameters of the conveyed media (temperature, pressure, and flow rate). Based on their function, they are classified into shut-off valves, check valves, control valves, etc., serving purposes such as on/off switching, regulation, flow guidance, prevention of backflow, pressure stabilization, diversion, or overflow/pressure relief.
Users must correctly select, install, operate, and maintain the valves to ensure normal functionality and guarantee personal and property safety.
2. Valve Selection
When selecting the valve type, carefully review the product manual and make your choice based on the operating conditions and technical specifications. During normal operation, the working pressure must not exceed the valve's Nominal Pressure (PN), and the working temperature must remain within the range specified by the valve. Do not exceed the allowable limits.
3. Valve Installation
Installation must be performed by qualified professionals. After installation, pressure testing must be conducted in accordance with standard requirements. The valve shall only be put into service after successful commissioning.
Excessive misalignment deviation between the two pipeline ends is not permitted; otherwise, excessive installation stress will be generated, leading to failure or damage. The thread accuracy and effective length must strictly comply with ISO 228 standards.
When tightening, apply the wrench to the hexagonal or octagonal section on the same side as the threaded end. Do not apply force to the opposite side of the valve to avoid deformation. PTFE (Polytetrafluoroethylene) tape or thread sealant must be used for sealing.
Use the appropriate torque wrench or pipe wrench for installation and tightening. Tighten only to the effective thread length; do not over-tighten, as this may cause the thread to press against the internal end face, resulting in ball damage and leakage. To ensure normal operation, it is recommended to install a strainer at the pipeline inlet.
4. Operation, Maintenance and Service
The handle or handwheel of the ball valve is designed based on the service conditions and corresponding torque requirements. Do not substitute it with an extended lever, as excessive operating torque may damage the valve. Additionally, an excessively high closing speed may cause a water hammer effect, resulting in a momentary pressure surge.
Frequent fluctuations in pipeline pressure or temperature will shorten the service life. Corresponding preventive measures should be designed into the system.
The stem sealing packing is made of PTFE (Polytetrafluoroethylene). In case of leakage due to corrosion, the packing can be compensated by tightening the gland nut. Note: The packing must only be replaced after the internal medium pressure has been relieved.