AERCO Electronic Control Valve - Manual (Page 28)

8-4
CM27. Inspect the Valve Seat (7). If it is worn so that it will not seat properly with the Seat Cage (2), with
the Valve Stem (12), it must be replaced.
CM28. THOROUGHLY clean and inspect the seating and inner surfaces of the Seat Cage (2). If the
seating surface around the top of the Cage is worn or damaged so that the Valve Seat (7) will not
seat properly, or if the inner surfaces of the Cage are scored or damaged so that the Valve Plug
(5) or Pistons (3) and (6) will not move up and down freely, the Cage (2) must be replaced.
CM29. If the Cage (2) must be removed from the Valve Body (1), it will be necessary to fabricate a tool,
such as shown in Figure 8-3 for Cage removal. Insert the tool into the slots on top of the Cage (2)
and turn the Cage out of the Valve Body. To obtain a Cage Removal tool, contact AERCO or your
nearest Sales Representative.
VALVE REASSEMBLY
Refer to Figure 8-1 or Figure 8-2 when performing the following procedures.
CM30. If the Seat Cage has been removed, place a NEW Seat Cage Gasket (24) on the seating surface
of the Valve Body. Next, replace the Seat Cage (2) into the Valve Body (1), using the tool
described in Step CM29. Make the Seat Cage tight.
CM31. If disassembled or being replaced, reassemble the Top Piston (6) and Bottom Piston (3) onto the
Valve Plug Shaft (5), using the Top Piston Retaining Nut (46) (1-inch through 2-inch Valves), and
Bottom Piston Retaining Nut (50) or Bottom Piston Retaining Ring (4).
CM32. For Control Valves, 1-inch through 2-inch, (Figure 8-1), reassemble the Valve Plug/Seat/Shaft
assembly in the following order:
• Valve Plug (5)
• Seat Retainer (34)
• Valve Seat (7)
• Retaining Disc (8)
• Valve Stem (12) and Lower Shaft (16)
• Valve Stem Retaining Nut (35)
• Pilot
Spring (10)
• Pilot Spring Retaining Clip (3)
• Lock
Washer (23)
CM33. For Control Valves, 2.5-inch, 3-inch and 4-inch, (Figure 8-2), reassemble the Piston/Seat/Shaft
assembly in the following order:
• Top Piston (6) and Bottom Piston (3) assembly
• Valve Seat (7)
• Valve Stem (12) and Lower Shaft (16)
• Valve Seat Retaining Disc (8)
• Cap
Screws (9)
• Pilot Spring (10)
• Pilot Spring Back-Up Washer (31), 4-inch Valve only
• Pilot Spring Retainer (11)
• Lock
Washer (23)