Failures And Elimination Methods Of Sanitary Large-diameter Butterfly Valves

Sanitary Butterfly Valve requirements and protection:

To extend the life of the valve and ensure the valve hygiene requirements, the metal surface of the valve must be painted, the coating thickness must be guaranteed, and the coating process must be done before the metal surface treatment reaches the grade (near white grade), and thermal spraying is recommended. The outer surface of the valve installed outdoors should be coated with UV-resistant acrylic paint.

Failures and elimination methods of sanitary large-diameter butterfly valves:

1. Before installation, please confirm whether the product performance and the medium flow direction arrow are consistent with the movement conditions, and clean the inner cavity of the valve. It is not allowed to have impurities and foreign matter on the sealing ring and butterfly plate. The butterfly plate is never allowed to be closed before cleaning to avoid damaging the sealing ring.

2. It is recommended to use a special flange for butterfly valves, that is, HGJ54-91 socket welding steel flange, for the matching flange of the disc plate.

3. The best position for installation in the pipeline is vertical installation, but it cannot be inverted.

4. The flow needs to be adjusted during use, and a worm gear box is used for control.

5. For butterfly valves with a large number of opening and closing times, open the worm gear box cover every two months or so to check whether the grease is normal. The right amount of grease should be maintained.

6. Check that each connection part requires compression, which ensures the stability of the packing and the flexibility of the valve stem.

7. Metal-sealed sanitary butterfly valves are not suitable for installation at the end of the pipeline. If they must be installed at the end of the pipeline, they must be equipped with outlet flanges to prevent the sealing ring from backlogging and over-positioning.

8. The valve stem installation and use reaction should regularly check the valve use effect and eliminate the faults in time.

9. The possible faults that may occur are detailed in the following table: Common faults and solutions for sanitary butterfly valves

Key maintenance parts of sanitary large-diameter butterfly valves

Valve seat: In the case of high pressure difference and corrosive media, the valve seat is often impacted and corroded by the medium. It is necessary to focus on checking the pressure resistance, corrosion resistance and wear and aging. If the corrosion is strong, the fluororubber valve seat can be replaced.

Butterfly plate: Butterfly plate is one of the movable parts of sanitary large-diameter butterfly valve, which is seriously eroded by the medium. During maintenance, carefully check whether the valve core is corroded and worn, especially under high pressure difference. The wear of the valve core is more serious due to cavitation caused by cavitation. The valve core with serious damage should be replaced.

Check whether the rubber film in the actuator is aging and cracking.

Possible causes and solutions of sanitary large-diameter butterfly valve

1. Sealing surface leakage

1. There are debris in the butterfly plate and sealing surface

2. The closing position of the butterfly plate and the sealing surface is not correct

3. The sealing surface and the butterfly plate are in close contact and cause damage

Solution

1. Eliminate impurities and clean the inner cavity of the valve

2. Adjust the adjusting screw of the worm gear or electric actuator to achieve the correct valve closing position

3. Check the mounting flange plane and the bolt compression country, which should be evenly compressed

4. Apply pressure in the direction of the tip seal