Having a long service life and maintenance free period will depend on normal working conditions, maintaining a harmonious temperature/pressure ratio, and reasonable corrosion data
Ball valve in the closed state, there is still pressure fluid inside the valve body
Remove line pressure and position valve in open position before servicing
Disconnect power or air supply before servicing
Disengage the actuator from the support before servicing
It is necessary to make sure that pressure has been removed from the upper and downstream pipes of the ball valve before disassembly and disassembly operation
Care must be taken to prevent damage to the sealing surface of the parts, especially non-metallic parts, and special tools should be used when removing the O-ring
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 medium (such as gas) in ball valve. When the working medium is gas, the metal parts can be cleaned with gasoline (GB484-89). Non-metallic parts shall be cleaned with purified water or alcohol
The non-metallic parts should be removed from the cleaning agent immediately after cleaning, and should not be soaked for a long time
After cleaning to be washed wall surface cleaning agent volatilization (can not be soaked in cleaning agent of silk cloth wipe) assembly, but not for a long time, otherwise it will rust, dust pollution
New parts also need to be cleaned before assembly
No contamination, adhesion or retention on the surface of the parts or into the inner cavity shall be allowed during assembly, such as metal debris, fiber, grease (except for specified use) and other impurities and foreign matter, etc. In case of microleakage in the packing, the stem nut shall be re-locked.
Note: Do not lock too tight, usually lock 1/4 turn ~ 1 turn, leakage will stop.
A), remove
Keep valve in half open position to flush and remove any hazardous substances that may exist inside and outside the valve body.
Close the ball valve, remove the connecting bolts and nuts from the flanges on both sides, and remove the valve completely from the line.
Remove drive assembly - actuator, connection bracket, release washer, stem nut, butterfly shrapnel, gnam, wear plate, stem packing in sequence.
Remove cover coupling bolts and nuts, separate cover from body and remove cover washer.
Make sure the ball is in the "off" position to easily remove it from the body and then remove the seat.
Push stem down through body center hole until completely removed, then remove O-ring and stem underpacking.
Caution: Use caution to avoid chafing stem surface and body stuffing box seal.
B) Reassemble
Clean and inspect disassembled parts and it is highly recommended to replace seals such as seat and bonnet gaskets with a spare part pack.
Assemble in reverse order of disassembly.
Cross-lock flange connecting bolts with specified torque.
Lock stem nut with specified torque.
After installing the actuator, input the corresponding signal and rotate the spool by rotating the stem to bring the valve to the open and close position.
If possible, perform pressure seal test and performance test on valves according to relevant standards before piping is refitted.
