How to use sanitary pneumatic diverter valve?

sanitary pneumatic diverter valve has many advantages such as simple structure, low cost, easy manufacturing, strong reliability, etc. Therefore, synchronous valves have been widely used in hydraulic systems. The synchronization of sanitary pneumatic diverter valve is speed synchronization. When two cylinders or multiple cylinders bear different loads, the sanitary pneumatic diverter valve can still ensure their synchronous movement.

 

Which parts of the sanitary pneumatic diverter valve need to be inspected during maintenance?

The action of sanitary pneumatic diverter valve is unstable. What could be the fault phenomenon and cause?

What are the ways to avoid cavitation in sanitary pneumatic diverter valve?

 

 

Which parts of the sanitary pneumatic diverter valve need to be inspected during maintenance?

Key inspection parts during maintenance

1. Check the inner wall of the compartment: In the case of high pressure difference and corrosive medium, the inner wall of the valve and the diaphragm of the diaphragm valve are usually impacted and corroded by the medium. It is necessary to check the pressure and corrosion resistance of the sanitary pneumatic diverter valve;

2. Check the valve seat: due to the infiltration of the medium during work, the threaded inner surface for fixing the valve seat is easily corroded and the valve seat is loose;

3. Check the spool: the spool is one of the movable parts of the sanitary pneumatic diverter valve, and it is more severely eroded by the medium. When overhauling, check carefully whether all parts of the spool are corroded and worn, especially under the condition of high pressure difference. , The cavitation phenomenon caused by cavitation caused by the wear of the valve core is more serious. Severely damaged valve core should be replaced; check the sealing packing: check whether the packing asbestos rope is dry, if PTFE packing is used, pay attention to check whether it is aging and whether its mating surface is damaged;

4. Check whether the rubber membrane in the sanitary pneumatic diverter valve actuator is aging or cracked.

 

The action of sanitary pneumatic diverter valve is unstable. What could be the fault phenomenon and cause?

1.The pressure of sanitary pneumatic diverter valve is unstable.

2. The signal pressure of sanitary pneumatic diverter valve is unstable. ①The time constant (T=RC) of the control system is inappropriate; ②The output of the regulator is unstable.

3. The air source pressure is stable and the signal pressure is also stable, but the action of the sanitary pneumatic diverter valve is still unstable. ①The ball valve of the amplifier in the positioner is not tightly closed due to dirt and wear, and the output will oscillate when the air consumption is particularly increased; ②The nozzle baffle of the amplifier in the positioner is not parallel, and the baffle cannot cover the nozzle; ③The output tube 、Line leakage; ④The rigidity of the actuator is too small; ⑤The frictional resistance in the movement of the valve stem is large, and the contact part is blocked.

 

What are the ways to avoid cavitation in sanitary pneumatic diverter valve?

1.Improve the valve core and valve seat design of sanitary pneumatic diverter valve, so that it has reasonable liquid flow velocity distribution and pressure distribution.

2. When the sanitary pneumatic diverter valve conditions are sufficient, inflate in the liquid flow to partially or completely eliminate the low pressure area.

3. Valves are used in series to reduce the pressure drop of each valve.

4. Make the pressure difference between the front and back of the sanitary pneumatic diverter valve lower than the maximum allowable pressure difference of the medium that produces cavitation at the inlet temperature of the regulating valve.

5. The medium works in the "flow open" state, and the allowable pressure difference is more than three times larger than the "flow closed" state.

 

Xusheng Valves (compact valves), as a Chinese pioneer in producing sanitary pneumatic diverter valves, can ensure the products’ quality and the after-sales service