AERCO Electronic Control Valve - Manual (Page 25)

VA-115 INSTRUCTIONS – ELECTRONIC CONTROL VALVE, CXT-E
8-1
8 - CORRECTIVE MAINTENANCE
INTRODUCTION
This Section provides corrective maintenance for all sizes of Electronic Control Valves, Type CXT-E
CXT-E CONTROL VALVE CORRECTIVE MAINTENANCE
The corrective maintenance procedures for the Electronic Control Valve are divided into the following
major areas:
• Valve Shaft Seal Retainer Replacement
• Valve
Disassembly
• Valve Reassembly
• Actuator Replacement
• Linkage Replacement
Refer to the applicable paragraphs which follow and perform the Corrective Maintenance steps indicated.
VALVE SHAFT SEAL RETAINER REPLACEMENT
Refer to Figure 8-1 or Figure 8-2 and proceed as follows:
WARNING
Ensure that the Control Valve has been isolated from the steam or hot (boiler)
water supply. Live steam or hot water can cause serious burns to personnel.
WARNING
Ensure that all electrical power to the Control Valve Actuator has been
disconnected. Serious personal injury may result if this Warning is not observed.
CM1. Loosen the Hex Nuts (17) under the Indicator Plate (Figure 8-1 or 8-2) approximately a half turn
clockwise.
CM2. Disconnect the Linkage Adapter from the Valve Shaft (16) by turning the Shaft clockwise (as
viewed from above). If the Valve Shaft cannot be turned by hand, use an open-end wrench to turn
the “double-nuts” on the Shaft until it disengages the Linkage Adapter threads.
CM3. Remove the Indicator Plate from the Valve Shaft (16).
CM4. Remove the two Cap Screws (19) securing the Linkage Assembly (26) to the Valve Top (21).
CM5. Remove the complete Linkage Assembly (26), with the Actuator Assembly (27) still attached,
from the Valve Top. Also, remove the Gasket (29).
CM6. If the Packing Nut (18) is faulty (leaking or binding the Shaft (16), it must be replaced.
CM7. Measure and record the current position of the Hex Nuts (17) from the end of the Valve Shaft.
This will simplify adjustment of the Actuator Linkage during reassembly.