The Maintenance of the Ball Valve
The long service life and maintenance-free period of ball valves depend on the following several factors: normal operating conditions, maintaining a harmonious temperature or pressure ratio, and reasonable corrosion data.
Note:
● When the ball valve is in the closed state, there is still pressure fluid inside the valve body.
● Before the maintenance, release the pressure from the line and leave the valve in the open position.
● Before maintenance, disconnect the power or air source.
● Before maintenance, remove the actuator from the support.
● It is necessary to find out that the pressure on the ball valve and the downstream pipeline has been removed before disassembly and decomposition operation.
● During the decomposition and reassembly, we must be careful to prevent damage to the sealing surface of parts, especially non-metallic parts. We need to take out the O-ring when using special tools.
● The bolts on the flange must be tightened symmetrically, step by step and evenly during assembly.
● Cleaning agent should be compatible with rubber parts, plastic parts, metal parts and working media (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Non-metallic parts are cleaned with pure water or alcohol.
● The individual decomposed parts can be cleaned by immersion. The metal parts that have not decomposed down can be scrubbed with clean, fine and clean silk cloth impregnated with a cleaning agent (to avoid the fiber falling off and adhering to the parts). When cleaning, all grease, dirt, adhesive, dust and so on adhering to the wall must be removed.
● Non-metallic parts should be removed from the cleaning agent immediately after cleaning. It can not be soaked for a long time.
● After cleaning, it is necessary to be cleaned after the wall cleaning agent is volatilized (can be used to soak cleaning agent silk wipe) for assembly. It can not be put aside for a long time, otherwise, it will rust. Finally, it may cause dust pollution.
● New parts also need to be cleaned before assembly.
● Use grease for lubrication. Grease should be compatible with metal materials of the ball valve, rubber parts, plastic parts and working media. When the working medium is gas, special 221 greases can be used. Apply a thin layer of grease to the surface of the seal mounting tank and apply a thin layer of grease to the sealing surface and friction surface of the valve stem.
● No metal debris, fiber, grease (except specified use) dust and other impurities, foreign bodies and other pollution, or adhesion. They can not stay on the surface of the parts or in the inner cavity during assembly.
1) The stuffing place should be locked again
If there is micro-leakage in the packing, lock the stem nut again.
Note: Do not lock too tightly. Usually, leakage will stop by locking another 1/4 circle to 1 circle.
2) Replace the seat and seal
A) Disassembly
Make the valve in the half-open position, wash and remove the body inside and outside the possible hazardous substances.
Close the ball valve, remove the connection bolts and nuts from both flanges, and remove the valve completely from the line.
Remove the drive device–the actuator, connection bracket, anti-loose washer, stem nut, butterfly shrapnel, glam, wear plate and stem packing in sequence.
Remove cover connection bolts and nuts, separate the cover from the body and remove the cover washer.
Verify that the ball is in the "off" position. This allows it to be easily removed from the body and then removed from the seat.
Push the stem down through the valve body center hole until it is completely removed, then remove the O-ring and stem underpacking.
Note: use caution to avoid chafing the stem surface and body packing box seal.
B) Reassemble
Clean and inspect the removed parts. It is highly recommended to replace the seals such as the seat and cover washer with spare parts package.
Assemble in reverse order of disassembly.
Cross-lock flange connection bolts with specified torque.
Lock stem nut with specified torque.
After the actuator is installed, input the corresponding signal to rotate the spool by rotating the valve stem to make the valve open and closed.
If possible, perform a pressure seal test and performance test of the valve according to the relevant standards before reloading the pipe.
Note:
● When the ball valve is in the closed state, there is still pressure fluid inside the valve body.
● Before the maintenance, release the pressure from the line and leave the valve in the open position.
● Before maintenance, disconnect the power or air source.
● Before maintenance, remove the actuator from the support.
● It is necessary to find out that the pressure on the ball valve and the downstream pipeline has been removed before disassembly and decomposition operation.
● During the decomposition and reassembly, we must be careful to prevent damage to the sealing surface of parts, especially non-metallic parts. We need to take out the O-ring when using special tools.
● The bolts on the flange must be tightened symmetrically, step by step and evenly during assembly.
● Cleaning agent should be compatible with rubber parts, plastic parts, metal parts and working media (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Non-metallic parts are cleaned with pure water or alcohol.
● The individual decomposed parts can be cleaned by immersion. The metal parts that have not decomposed down can be scrubbed with clean, fine and clean silk cloth impregnated with a cleaning agent (to avoid the fiber falling off and adhering to the parts). When cleaning, all grease, dirt, adhesive, dust and so on adhering to the wall must be removed.
● Non-metallic parts should be removed from the cleaning agent immediately after cleaning. It can not be soaked for a long time.
● After cleaning, it is necessary to be cleaned after the wall cleaning agent is volatilized (can be used to soak cleaning agent silk wipe) for assembly. It can not be put aside for a long time, otherwise, it will rust. Finally, it may cause dust pollution.
● New parts also need to be cleaned before assembly.
● Use grease for lubrication. Grease should be compatible with metal materials of the ball valve, rubber parts, plastic parts and working media. When the working medium is gas, special 221 greases can be used. Apply a thin layer of grease to the surface of the seal mounting tank and apply a thin layer of grease to the sealing surface and friction surface of the valve stem.
● No metal debris, fiber, grease (except specified use) dust and other impurities, foreign bodies and other pollution, or adhesion. They can not stay on the surface of the parts or in the inner cavity during assembly.
1) The stuffing place should be locked again
If there is micro-leakage in the packing, lock the stem nut again.
Note: Do not lock too tightly. Usually, leakage will stop by locking another 1/4 circle to 1 circle.
2) Replace the seat and seal
A) Disassembly
Make the valve in the half-open position, wash and remove the body inside and outside the possible hazardous substances.
Close the ball valve, remove the connection bolts and nuts from both flanges, and remove the valve completely from the line.
Remove the drive device–the actuator, connection bracket, anti-loose washer, stem nut, butterfly shrapnel, glam, wear plate and stem packing in sequence.
Remove cover connection bolts and nuts, separate the cover from the body and remove the cover washer.
Verify that the ball is in the "off" position. This allows it to be easily removed from the body and then removed from the seat.
Push the stem down through the valve body center hole until it is completely removed, then remove the O-ring and stem underpacking.
Note: use caution to avoid chafing the stem surface and body packing box seal.
B) Reassemble
Clean and inspect the removed parts. It is highly recommended to replace the seals such as the seat and cover washer with spare parts package.
Assemble in reverse order of disassembly.
Cross-lock flange connection bolts with specified torque.
Lock stem nut with specified torque.
After the actuator is installed, input the corresponding signal to rotate the spool by rotating the valve stem to make the valve open and closed.
If possible, perform a pressure seal test and performance test of the valve according to the relevant standards before reloading the pipe.
