AERCO Electronic Controls System (ECS) - Manual (Page 49)

Electronic Control System (ECS) and Type CXT-E Valve
8. CORRECTIVE MAINTENANCE
VD2: 02/28/14 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 Page 49 of 82
AC-105 OMM-0003_0D
7) For Control Valves, 1-inch through 2-inch (Figure 8-1), disassemble the Shaft/Seat/Piston
assembly in the following order:
a) Lock Washer (23)
b) Retaining Ring (11)
c) Pilot Spring (10)
d) Valve Stem Retaining Nut (35)
e) Lower Shaft (16) and Valve Stem (12)
f) Retaining Disc (8)
g) Disc Seat (7)
h) Seat Retainer (34)
i) Valve Plug Shaft (5)
8) 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:
a) Lock Washer (23)
b) Pilot Spring Retainer (11)
c) Pilot Spring Back-Up Washer (31), 4-inch Valve only
d) Pilot Spring (10)
e) Cap Screws (9)
f) Valve Seat Retaining Disc (8)
g) Lower Shaft (16) and Valve Stern (12)
h) Valve Seat (7)
i) Top Piston (6) and Bottom Piston (3) assembly
9) 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.
10) 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).
11) 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.
12) 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.
13) Inspect the Valve Seat (7). If it is worn and does not seat properly with the Seat Cage (2),
(or Valve Stem (12) for 2.5 to 4 inch Valves), it must be replaced.
14) THOROUGHLY clean and inspect the seating and inner surfaces of the Seat Cage (2). If
the 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.