Alfa Laval Air Actuated Valve 771S-21M-15-X-316L

IMPORTANT: The TYPE 15/25 actuator does not have a red indicating cap like the type 10, 20 or 30 actuator. Cover the actuator stem threads with tape to protect the new bushing and packing from damage during assembly

- Actuator spring is not contained. Although preload force is low, caution must be used when spring force is released. Hand pressure must be applied to the cylinder top restricting its travel. Completely remove the actuator from the valve and follow the steps below

- Insert four bolts into bonnet and clamp into vise

- Remove air coupler adapter and nut by turning counterclockwise

- Remove actuator cylinder from bonnet by applying a strap wrench to the cylinder and turn counter clockwise completely two times

- Pull cylinder assembly off the bonnet and remove spring

- Separate diaphragm assembly from cylinder by holding cylinder and pulling on actuator stem

- Place diaphragm assembly into a vise and secure Inner Diaphragm Guide. Do Not over tighten. Remove stem by locating a wrench around the flats and turn counter clockwise. Remove adapter and nut. The nut may be removed by inserting a punch into the hole in its face, and tapping nut counter clockwise

Inspect Valve Body Seat(s) for nicks and scratches and other signs of excessive wear

Inspect Valve Stem & Seat(s) rubber or PTFE seat(s) for signs of cracking, tearing, checking, or excessive wear

Inspect stem finish for galling, nicks, or scratches

Inspect Split Bushing for signs of cracks, nicks, scratches or excessive wear on inside diameter

Inspect O-ring(s) for cuts, abrasions, flat spots, or other damage

Upload photos of any damage found

Sign off on the valve inspection