1、 Precautions during installation phase

1. Flow direction and support
   • Ensure that the flow direction of the valve is consistent with the flow direction of the medium, and the arrow markings should be clearly visible.
   • Large valves require independent support to avoid valve body deformation or seal failure caused by pipeline pressure. For example, it is recommended to install brackets for valves above DN300.
2. Space and fittings
   • When installed vertically, a space of 6 times the diameter of the valve should be reserved behind the valve (such as 1.2 meters for DN200 valves) to prevent obstruction of the valve disc opening.
   • Avoid installing variable diameter pipes or pipe joints before and after the valve to reduce the impact of turbulence on the valve disc.
3. Connection and sealing
   • When connecting flanges, bolts should be tightened evenly to prevent local leakage.
   • Clean the inner cavity before installation, remove debris, and avoid scratching the sealing surface.

2、 Key operations during the debugging phase

1. Rough tuning preparation
   • Fill the isolation device capsule with water and open the micro control valve to 50% opening.
   • Adjust the piston screw so that the pull rod extends 1/3 of its total length, and fix the nut after the piston extends 2/3.
2. Start testing
   • After starting the water pump, observe whether the piston rod is pushed up within 15-30 seconds. If it is not pushed up, check the one-way valve or pressure pipeline.
   • Observe the slow closing of the valve disc during shutdown. If the motor reverses or the seal is not tight, adjust the needle valve opening or clean the pipeline.
3. Slow closing time adjustment
   • Rotate the needle valve handle clockwise to reduce the opening and extend the valve disc closing time (up to 60 seconds); Rotate counterclockwise to shorten the time.
   • Adjusting the opening adjustment rod can change the extension length of the piston rod, thereby controlling the slow closing opening. For example, turning the adjusting rod nut clockwise can reduce the slow closing opening.

3、 Key points of operation and maintenance

1. regular inspection
   • Check the sealing performance monthly and replace the sealing ring promptly if any leaks are found.
   • Clean the inside of the valve quarterly to remove impurities and prevent piston sticking.
2. Maintenance of slow closing mechanism
   • Check the lubrication of the slow closing piston annually and add hydraulic oil if necessary.
   • After the winter water outage, it is necessary to clean the sludge inside the valve body to prevent frostbite of the oil cylinder seals.
3. Operating Specifications
   • Long term shutdown of valves requires regular opening and closing to prevent rusting or jamming.
   • Avoid using in environments with excessive pressure or temperature to prevent valve body deformation or seal failure.

4、 Adaptation to environment and working conditions

1. Media requirements
   • Suitable for media such as clean water, sewage, seawater, etc., but it is necessary to avoid large particle impurities (such as gravel) to prevent piston jamming.
   • Under mild corrosion conditions, it can be used for a long time, but in severely corrosive environments, corrosion-resistant materials (such as stainless steel valve bodies) should be selected.
2. Temperature and pressure limitations
   • The medium temperature should not exceed 80 ℃, and the pressure should be within the rated range of the valve (such as PN1.0MPa valve applicable pressure ≤ 1.0MPa).
   • Exceeding the rated value may cause valve disc deformation or seal failure.

5、 Typical fault handling

• Packing leakageTighten the packing gland nut evenly or replace the packing.
• Sealing surface leakageRemove dirt from the sealing surface, repair or replace the sealing ring.
• Valve disc cannot be closedCheck if the needle valve is blocked, or adjust the position of the heavy hammer to balance the weight of the valve disc.