AERCO Electronic Control Valve - Manual (Page 27)

VA-115 INSTRUCTIONS – ELECTRONIC CONTROL VALVE, CXT-E
8-3
CM20. Grasp the Lower Shaft (16) and carefully lift out the ENTIRE Shaft/Seat/Piston Assembly.
CM21. For Control Valves, 1-inch through 2-inch (Figure 8-1), disassemble the Shaft/Seat/Piston
assembly in the following order:
• Lock Washer (23)
• Retaining Ring (11)
• Pilot
Spring (10)
• Valve Stem Retaining Nut (35)
• Lower Shaft (16) and Valve Stem (12)
• Retaining Disc (8)
• Disc Seat (7)
• Seat Retainer (34)
• Valve Plug Shaft (5)
CM22. For Control Valves, 2.5-inch, 3-inch and 4-inch, (refer to Figure 8-2), disassemble the
Shaft/Seat/Piston Assembly in the following order:
• Lock Washer (23)
• Pilot Spring Retainer (11)
• Pilot Spring Back-Up Washer (31), 4-inch Valve only
• Pilot
Spring (10)
• Cap Screws (9)
• Retaining Disc (8)
• Lower Shaft (16) and Valve Stern (12)
• Valve Seat (7)
• Top Piston (6) and Bottom Piston (3) assembly
CM23. It is recommended that the Seat Cage (2) NOT BE DISASSEMBLED unless it must be replaced.
See Step CM29.
NOTE
In any cleaning operation called for in these instructions, ALWAYS clean all
denoted parts thoroughly of all dirt and scale. Always use a clean cloth and, if
necessary, a solvent. NEVER use emery cloth or sandpaper unless instructed
otherwise herein.
CM24. CLEAN ALL PARTS THOROUGHLY. ALL DIRT AND/OR SCALE MUST BE REMOVED from the
outer surfaces of the Valve Plug Shaft (5) (Figure 8-1) or the Top Piston (6) and Bottom Piston (3)
(Figure 8-2) and from the surface of the Valve Stem (12).
CM25. Inspect the Valve Stem (12). If it is damaged or it does not seat properly on the Valve Seat (7), or
does not move freely in the Valve Seat Retaining Disc (8), the Valve Stem (12), Pilot Spring
Retainer (11) and Pilot Spring (10) must be replaced.
CM26. Inspect the outer surfaces of the Valve Plug (5) or the Top Piston (6) and Bottom Piston (3). If
they are scored or damaged so that they will not move freely up and down in the Seat Cage (2),
the Valve Plug or Pistons must be replaced. Also see Step CM32.