ASAHI AV VALVES Installation Operation and Maintenance Manual
Butterfly Valves Type57L-IS (Lug style) 14
4) Insert the stem  about 1/3 into the body . Install the seat  into the body  by aligning upper seat stem hole
with the stem .
5) Collapse the left or right side of seat  in towards opposing side exposing lower stem hole by screw driver (–).
Install the retaining ring  into the body  aligning tabs of ring with center groove of the body . Seat 
tabs should line up when bottom of seat is reset into body of valve.
6) Remove the stem .
7) Reset the seat  into the body .
- Make certain retaining rings  sit flush inside of seat  with tabs properly aligned. If retaining
rings  are not installed correctly, the seat  will not sit in the body  properly. This is indicated
by a visible gap between seat  and body , and disc  will not fit properly.
8) To install disc , make certain valve size on disc  is in upright direction. Install top of disc  into seat 
aligning with upper stem hole.
9) Rotate disc  to 75% (Approx.) closed position and install stem  about 50% into the body .
10) Press in bottom of disc  to lower stem hole.
- Look into valve body  to be certain full square in disc  is centered with upper valve  stem hole.
If not, repeat step 8), 9), and 10).
Make certain line scribed on top of stem  indicates disc  position while installing stem .
11) Install the stem  into valve body  and disc . If disc  is properly aligned, stem  should slide in smoothly.
If stem  does not slide in smoothly, repeat from step 8) to properly align the disc  in the valve body .
12) Install stem holder  onto valve body  with countersunk holes facing up using 4 screws .
13) To install lever or gear operator reverse disassembly procedure #5).
14) After assembly, make sure that the valve can be fully opened and closed smoothly.