AERCO SWDW68 U-Tube Double-Wall Heaters w/ECS - Manual (Page 39)

Rev B Mar 2013 6-1
CHAPTER 6 SCHEDULED MAINTENANCE
6.1 INTRODUCTION
This chapter lists the preventive maintenance procedures recommended for the heat exchanger and
Electronic Control System (ECS). These recommendations include procedures to be performed each
week (6.2), month (6.3), quarter (6.4), six-month interval (6.5) and year (6.6).
The recommended preventive maintenance schedule is summarized in Table 6-1 at the end of this
chapter.
6.2 WEEKLY MAINTENANCE
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Tube Leaks
Check the leak detection tube once each week for evidence of leaks in the heat exchanger tubes.
MAKE CERTAIN THAT THE DETECTION TUBE NEVER GETS PLUGGED. If any fluid is escaping
from the detection tube, shut down the heat exchanger as outlined in Section 5.4 and see Section 9.2
to investigate the leak.
6.3 MONTHLY MAINTENANCE
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Steam Strainer
After the first month of operation, clean the strainer in the Steam Input line in accordance with the
instructions furnished with the strainer.
□
CXT-E Control Valve
Check the CXT-E Control Valve (“Valve”) for leaks, as follows:
1. Referring to Figure 6-1, check the packing nut and Valve top for evidence of leakage.
INDICATOR
PLATE
VALVE
TOP
PACKING
NUT
P/O LINKAGE
ASSEMBLY
LOWER
SHAFT
Figure 6-1. Valve Shaft Seals
2. If there is leakage between the packing nut and Valve top, tighten the packing nut until the leakage
stops. DO NOT FORCE the packing nut.
CAUTION
Take care not to over-tighten the packing nut to avoid trapping the valve
stem and slowing or stopping Valve motion.
3. If tightening the packing nut does not stop the leak, the packing nut and packing assembly must be
replaced in accordance with the procedures specified in Sections 8.2.2 and 8.2.3.