How to Maintain Ball Valve?

Ball valve can be used for regulation and control of fluid. Ball valve can be classified as pneumatic ball valve, electric ball valve and manual ball valve according to the driving mode. The maintenance methods of ball valve are introduced below.

Routine Maintenance

The service life and maintenance-free life of the ball valve depend on the following factors: normal working conditions, appropriate temperature / pressure ratio, and reasonable corrosion data. When the ball valve is closed, there is still some compressed fluids in the valve body. Before servicing the ball valve, the pipe pressure should be relieved and the valve should be in the open position. In addition, it is necessary to disconnect the power supply or air supply and remove the ball valve from the equipment. You must avoid damage to the sealing surface of the part, especially non-metallic parts, when decomposing and assembling the ball valve. When removing the sealing ring, use a special tool to avoid damage.

Choose a cleaner that is harmless to all parts of the ball valve to clean the ball valve, and the cleaner must be able to dissolve with the fluid in the ball valve. If the fluid in the ball valve is gas, gasoline can be used to clean the metal parts of the ball valve. The rest of the non-metallic parts can be cleaned with pure water or alcohol. At the same time, non-metallic parts should be removed from the cleaner immediately after cleaning and should not be soaked for a long time.

After cleaning, you need to wait for the cleaner on the part to be evaporated before assembling the part to the ball valve. The cleaned parts must not be put on hold for a long time, otherwise they will rust and be contaminated by dust.

Disassembly of Ball Valve

1. Open the ball valve half, then flush and remove the possible hazardous substances inside and outside the valve body.

2. Close the ball valve, remove the connecting bolts and nuts on both flanges, and remove the valve completely from the pipe. 

3. Remove the driving device, actuator, connecting bracket, sealing gasket, valve-stem nut, leaf spring, wear resistant plate and valve stem packing of the ball valve in sequence. 

4. Remove the connecting bolts and nuts between the bonnet and the valve body, separate the bonnet from the valve body, and remove the bonnet gasket. 

5. Verify that the valve ball is in the "turn off" position, which makes it easier to take out of the valve body and then remove the valve seat.

6. Push the valve stem downward until it is fully removed, and then remove the O-ring and the filler at the valve stem.

Reassembly of Ball Valve

1. Clean and inspect the parts and replace the seal components such as the valve seat and the bonnet gasket with the spare part.

2. Assemble the parts of the ball valve in the reverse order in which the ball valve is disassembled.

3. Lock the connecting bolt of the flange with the specified torque.

4. Lock the valve stem nut with the specified torque.

5. After assembling the actuator, input the corresponding signal to drive the valve core to rotate by rotating the stem, which is used to adjust the valve to the open and closed position.

6. Before installing the ball valve on the pipe, the pressure seal test and performance test are carried out according to the relevant standards.