Type EZR
21
4. Install the replacement closing cap gasket (key 25)
if necessary and reinstall the closing cap (key 22).
5. If the spring was changed, be sure to change the
stamped spring range on the nameplate.
To Disassemble and Reassemble Diaphragm Parts
1. Remove the closing cap (key 22), and turn adjusting
screw (key 35) counterclockwise to remove adjusting
screw, baffle plate (key 56), and control spring (key 6).
2. Remove the spring case hex nuts (key 23, not
shown), cap screws (key 24), and spring case (key 3).
3. Remove the diaphragm (key 10) and attached
parts by tilting them so that the pusher post (key 8)
slips off the lever assembly (key 16). To separate
the diaphragm (key 10) from the attached parts,
unscrew the machine screw (key 38) from the
pusher post (key 8).
4. Inspect the pusher post (key 8) and the body seal
O-ring (key 11), replace if required.
5. Remove hex nut (key 21) to separate the
diaphragm (key 10) and attached parts.
6. To replace the lever assembly (key 16), remove
the machine screws (key 17). To replace the stem
(key 14) or access the stem seal O-ring (key 30)
also perform Body Area Maintenance procedure
steps 1 and 4 and pull the stem out of the
diaphragm casing (key 4).
7. Install the stem (key 14) into the guide insert (key 18)
and perform Body Area Maintenance procedure
steps 6 through 8 as necessary.
8. Install the lever assembly (key 16) into the stem
(key 14) and secure the lever assembly with the
machine screws (key 17).
9. Install the parts on the pusher post in the order
listed below:
• Pusher Post (key 8)
• Pusher Post Connector (key 40)
• Connector Seal O-ring (key 49)
• Diaphragm Head (key 7)
• Diaphragm (key 10), pattern side up
• Diaphragm Head (key 7)
• Hex Nut (key 21) — Tighten the hex nut
9 to 11 foot-pounds (12 to 15 N•m) to secure
parts to the pusher post connector (key 40)
• Overpressure Spring (key 39)
• Spring Holder (key 37)
• Machine Screw (key 38)
10. Insert and tighten the machine screw (key 38)
with a torque of 1 to 3 foot-pounds (1,4 to
4,1 N•m) to secure the diaphragm parts to
the pusher post (key 8).
11. Install the assembled parts in the diaphragm
casing (key 4). Make sure the lever (key 16)
fits in the pusher post (key 8) and that the holes
in the diaphragm (key 10) align with the holes in
the diaphragm casing.
12. Place the spring case (key 3) on the diaphragm
casing (key 4) so the vent assembly (key 26)
is oriented correctly, and secure with the cap
screws (key 24) and hex nuts (key 23, not shown),
fingertight only.
13. Insert the control spring (key 6) into the spring
case (key 3), followed by the baffle plate (key 56)
and
adjusting screw (key 35).
14. Turn the adjusting screw (key 35) clockwise
until there is enough spring (key 6) force to provide
proper slack to the diaphragm (key 10). Using
a crisscross pattern, tighten the cap screws
(key 24) and hex nuts (key 23, not shown) to 14
to 17 foot-pounds (19 to 23 N•m) of torque. To
adjust the outlet pressure to the desired setting,
refer to Startup and Adjustment section.
15. Install a replacement closing cap gasket (key 25)
if necessary, and then install the closing cap (key 22).
PRX Series Maintenance
cAUTIOn
Always remove spring compression before
performing maintenance on this unit.
To remove spring compression, loosen
locknut (key 2, Figure 27) and back out
adjusting screw (key 1) until compression
is removed from the spring (key 7).
Lower Case Maintenance
1. Remove pressure from the pilot.
2. Remove machine screws (key 10) from lower
cover (key 21) and the separate lower cover from
the body (key 16).
Figure 12.
Expanded View of the Body Area
Showing the O-ring and Back-up Ring Placement
BODY SEAL O-RING (KEY 11)
BACK-UP RING (KEY 50)
BODY (KEY 1)
