ASAHI AV VALVES Installation, Operation and Maintenance Manual
Butterfly Valve Type 57, 56, 56D Electric Actuated Type S 21
- Make certain stem hole of seat are properly aligned. The upper side stem hole of seat bush A  has
lager than seat bush B  of lower side. When the stem bush is assembled oppositely, the stem 
cannot be inserted.
- Make certain tabs are properly aligned.
6) Insert the stem  of the body .
7) Install the stem holder  onto valve body  with countersunk holes facing up using 4 screws .
8) Install the actuator  and stand  onto the valve body using bolt (E)  and bolt (K) .
9) After assembly, make sure that the valve can be fully opened and closed smoothly.
10) Fully open or close the valve by motor-driven operation. (Refer to page 17)
- Nominal size 400mm (16”)
1) Before starting assembly, grease (Silicone) should be spread on the
2) Put the O-ring (C)  onto the stem . Put the O-ring (A) 
and O-ring (B)  onto the disc .
3) Grease (Silicone) should be spread on the top and bottom disc ,
the stem of the seat .
4) Put it into the state of open the valve slightly. Insert the set of seat
- disc  into the body .
5) Insert the stem  of the body .
6) To install gear operator reverse disassembly procedure #5).
*Make certain line scribed on top of stem  indicates disc 
position while installing stem .
7) After assembly, make sure that the valve can be fully opened and closed smoothly.
Nominal size: 400mm (16”)
Actuator type: SRJ Actuator type: LTRM, LTMD, LTRH
Stem hole is large size
Stem hole is small size
Concave part of seat bush
Convex part of seat bush