Fisher EZL Instruction Manual page 13

The body (key 1) may remain on the pipe
nipple (key 21, Figure 8 or key 24, Figure 9)
unless the entire pilot is replaced.
1. To gain access to the diaphragm assembly (key 5),
diaphragm limiter (key 23) if used, control spring
(key 6), restriction (key 22), stem guide (key 8),
or spring seat (key 7), remove the closing cap
(key 11), loosen the locknut (key 10), and turn the
adjusting screw (key 9) counter clockwise until
compression is removed from the spring. Remove
the machine screws (key 14), and separate the
body from the spring case (key 2).
2. Inspect the removed parts, and replace as
necessary. Make sure the restriction and the
registration hole in the body are free from debris.
After assembly, make sure of the proper control
spring setting according to the Startup section, and
re-mark the spring case if necessary.
3. To replace the valve plug (key 4) or bellows O-ring
(key 17), remove the body plug (key 3) and body
plug gasket (key 12). Be careful to keep the
bellows assembly (key 16) from falling out and
possibly getting lost while removing the valve
plug. Inspect the removed parts, and replace
as necessary. Make sure the valve plug seating
surfaces are free from debris.
61 Series Pilot
Perform this procedure if changing the control spring
for one of a different range, or if inspecting, cleaning,
or replacing relief valve or any other pilot parts. Pilot
part key numbers are referenced in Figure 9.
1. Remove the pilot from the pipe nipple (key 24)
unless just the control spring is to be changed.
2. To gain access to the control spring or other
internal parts, remove the closing cap assembly
(key 5) and relieve control spring (key 7)
compression by turning the adjusting screw
(key 6) counter clockwise. Change the control
spring and install the adjusting screw and closing
cap assembly if no other maintenance will be
performed. Make sure of the proper control spring
setting according to the Installation and Startup
section, and restamp the nameplate if necessary.
3. For any other internal maintenance, relieve control
spring compression according to step 2. Then
remove the cap screws (key 20) and separate the
Note pilot into three sections; spring case (key 1), body
(key 2), and bottom cover (key 3).
4. To inspect the two diaphragms (keys 14 and 15)
thoroughly, remove the diaphragm nut (key 11),
hex nut (key 19), and the upper and lower relay
heads (keys 16 and 17). The projecting prong in
the body may be used as the restraining member
to keep the yoke from turning while removing the
nuts. Also inspect the O-ring (key 12), and replace
any parts as necessary.
5. Take the yoke (key 4) and attached parts out of
the body to examine the disk holder assembly
(key 9). Remove the relay orifice (key 8) to check
for clogging and replace if necessary.
6. To replace the disk holder assembly, first
unscrew the bleed orifice (key 10). Remove
it and the associated parts. Then unscrew
the disk holder assembly from the bleed valve
(key 26) to gain access to the relay spring
(key 13). Clean or replace any parts as necessary
before reassembling.
7. Upon reassembly, pay particular attention to the
following assembly suggestions.
a. Before replacing the diaphragm case or spring
case, be sure the yoke assembly is positioned
so that it will not bind or rub on the prong in the
relay body.
b. Avoid wrinkling the diaphragms when replacing
the diaphragm case and spring case.
c. Replace the diaphragm case, carefully working
the upper relay diaphragm (key 14) into the recess
in the diaphragm case. If the diaphragm case
rocks with respect to the pilot body, diaphragm is
probably wrinkled.
d. Replace the spring case, using care to smooth
the lower relay diaphragm (key 15) evenly into
the recess in the pilot body.
e. Install the eight cap screws, tightening them down
evenly in a crisscross pattern to avoid crushing the
diaphragm. Recommended final torque on these
cap screws is 10 to 12 foot-pounds / 14 to 16 N•m.
8. After assembly, make sure of the proper control
spring setting according to the Installation and
Startup section, and restamp the nameplate
(key 27) if needed.
Type EZL
13