1、 Preparation before installation

1. environment check
   • Ensure a dry and ventilated installation environment, avoiding high temperatures, high humidity, or corrosive gases. Regular inspection and removal of dirt are required during long-term storage, and rust proof oil should be applied to the moving parts and processing surfaces.
   • The valve should be installed horizontally, with the stem facing upwards, and installed in the direction of medium flow indicated by the arrow in the diagram.
2. Pipeline cleaning
   • Before installation, it is necessary to thoroughly flush the pipeline with a pressure of 0.3MPa to remove impurities such as metal powder, residual sealing materials, rust, etc., to prevent damage to the inner surface of the valve.
3. Equipment inspection
   • Check whether the valve model and parameters meet the on-site requirements, and confirm that the cylinder and position indicator are not damaged.
   • If installing an electromagnetic valve, it is necessary to ensure that the connection is well sealed.

2、 Installation Process Specification

1. Fasten securely
   • Connect the valve to a suitable pipeline, ensuring a tight connection to avoid leakage. When welding connections, it is necessary to prevent high temperatures from reaching the packing and other parts.
   • A straight pipe section with a length not less than 10 times the diameter of the pipeline (10D) should be left before and after the regulating valve to avoid the flow characteristics being affected by a too short straight pipe section.
2. Support and stability
   • Regulating valves generally require support under the valve to ensure stability and reliability. When installed horizontally in a vertical pipeline under special circumstances, support is also required (except for small-diameter valves).
   • Avoid adding additional stress to the valve to ensure its performance is not affected.
3. Reserved operating space
   • The minimum distance between the top of the regulating valve and the obstacle above is 450mm, the bottom is 500mm, and the side is 350mm, making it easy to disassemble and repair.

3、 Usage and operation specifications

1. Pre startup inspection
   • Check if the valve is in the correct working position, if the power wiring is connected correctly according to the electrical drawing, and if the power voltage meets the requirements.
   • Confirm that the sampling signal of the temperature sensing package is correct, and the installation position should not be directly below the pipeline to prevent oil accumulation at the bottom of the pipe from affecting the temperature sensing.
2. Monitoring during operation
   • Monitor the operation status of valves, including parameters such as pressure, temperature, flow rate, etc., to ensure that they are within the specified range (medium temperature -10~+100 ℃, ambient temperature+55 ℃).
   • Regularly check whether the valve position signal is correct. When using a HART or intelligent electrical valve positioner, it is necessary to confirm whether the valve position status information can be transmitted correctly.
3. Adjustment and Calibration
   • When adjusting the thermal expansion valve, it should be done under normal operation of the refrigeration unit. The compressor suction pressure should be used as the saturation pressure inside the evaporator, and the approximate evaporation temperature should be obtained by checking the table. The superheat should be compared with the return pipe temperature to verify.
   • When adjusting the adjusting screw, be patient and meticulous, and do not rotate too many or too quickly each time.

4、 Maintenance and upkeep

1. regular inspection
   • Regularly check the working status of valves, including leakage, noise, vibration, etc., and promptly handle any abnormalities found.
   • When cleaning and maintaining, it is necessary to first turn off the power and gas sources to avoid accidents.
2. Lubrication and rust prevention
   • Apply yellow dry oil, molybdenum disulfide, or graphite powder to the friction parts such as valve stem threads for lubrication.
   • Outdoor valves need to be equipped with protective covers to prevent rain, snow, dust, and rust stains.
3. Component replacement
   • Regularly replace vulnerable parts such as seals, filters, etc. to ensure valve performance.
   • Maintenance should be carried out by professionals to avoid equipment damage caused by self disassembly.

5、 Safety precautions

1. Prohibited from using beyond the scope
   • Do not use this product in flammable and explosive environments, and do not exceed the specified working pressure and temperature range.
2. Emergency situation handling
   • In case of emergency during use, immediately stop using and take emergency measures.
3. Power and gas source safety
   • Ensure that the power and gas sources meet the requirements, the power supply is normal, and the output signal is correct.
   • When the coil is charged, it is strictly prohibited to cover it to prevent overheating and burning.