Installation, Operation and Maintenance Manual
H-A003-E-15 Ball Valve Type 21・21α Pneumatic Actuated Type AA 28
(20) Disassembling method for replacing parts
- Wear protective gloves and safety goggles as fluid remain in the valve even if the pipeline is empty.
(You may be injured.)
- Take care not to over-tighten the Union Nut. (The valve can be damaged.)
- Do not use the pipe wrench. (The valve can be damaged.)
- Type 21 & Type 21 Alpha has not all same parts to make one complete. Please check and specify the
model from the valve overview.
● Strap wrench ● Allen wrench ● Handle (For manual operating Option : )
● Safety goggles ● Protective gloves ● Spanner wrench
1) Completely discharge fluid from pipes.
2) Shut the main air valve, and open the bypass valve to discharge air
from the actuator.
3) Turn off the power source of solenoid valve. (Only solenoid valve)
4) Loosen the union nuts  at right and left with a strap wrench.
5) Remove the body from the piping system.
6) Loosen nut and bolt (B)  with a spanner wrench, and remove stand
 from the top flange.
7) Loosen the bolt (A)  between the actuator  and the stand and
remove the actuator .
8) Loosen set screw  with an allen wrench, and remove joint 
from stem .
9) Engage the upper convex part of the handle with the concave part of
the union .
10) In the engaged state, turn the handle to loosen it and remove the union .
-Loosen the union
Ball valve type 21: Counter clockwise
Ball valve type 21α: Clockwise
11) Remove the seat  carefully by hand without damaging it.
12) Operate the valve to full close.
13) Push out the ball  by hand.
14) Push out the stem  from the top flange side to the body side.
Carry out the assembly work in the reverse procedure from item 14)
- With regard to item 11), before installing seat  on the valve, check the seat for its face and back
depression side = engagement with ball (Refer to page 4,5)
Ball valve type 21 Tighten
Ball valve type 21