AERCO Steam Generator - Manual (Page 14)

INSTRUCTIONS – AERCO HELITHERM STEAM GENERATOR MODEL SS1B-PLUS
SG-101-12
CORRECTIVE MAINTENANCE
Refer to the previous TROUBLESHOOTING
Table. The following are probable causes and
remedies for improper action of the Generator.
CM1. The Primary or Secondary Pressure
Gage may read wrong. Check each
with a gage that is known to be correct.
CM2. Primary Steam pressure is too low.
Check the Primary Steam pressure
gage below the Control Box. If the
reading is low, adjust the steam
pressure to that which is required. If
there is a restriction in the Primary
Steam supply line, the gage reading will
drop excessively when the Generator
calls for full steam even though the
pressure appears to be normal when the
load is light. If the Primary Steam
supply pressure is correct, its pressure
gage reading should reach design
pressure for steam in the coils as the
Generator Secondary Steam outlet
pressure drops. If it does not, check the
operation of the Primary Steam Control
Valve.
CM3. Water level is low or water supply fails.
Check the operation of the Level
Controller and Water Solenoid at the
Cold Water inlet.
CM4. Cold Water pressure is low. Check and
correct, if necessary, the Water
pressure to the Generator.
CM5. Condensate return piping has not been
installed so that the Condensate drains
freely by gravity and/or the Condensate
check valve leaks or has failed. If
necessary, rearrange the Condensate
return piping per step 6f in the
INSTALLATION Section. Inspect the
check valve and replace it if it is leaking
or has failed. Also, check to make sure
that there is no restriction in the
Condensate drain line.
CM6. Primary Steam supply line is not
properly trapped. Install a trap as
indicated in Figure SG-101-2.
CM7. The Primary Steam Control Valve does
not close. Check the instructions
covering the Valve.
CM8. The Primary Steam Control Valve does
not open. Check the instructions
covering the Valve.
CM9. The Secondary Steam pressure control
system is not operating properly. Check
the instructions covering the Pressure
Controller in the Control Box.
CM10. The Over-Pressure Limit System is out
of adjustment or some component of the
system has failed. Check out the
system setting per step OP8 under
OPERATING PROCEDURES above.
Inspect and repair or replace the
pressure switch and solenoid valve.
CM11. There is a leak in the Generator coil(s),
steam riser, or Condensate return,
causing water from the shell to leak into
the heating coil system, or steam or
condensate from the coil system into the
shell. To verify such a leak, shut off the
Primary Steam supply and break a
connection in the Condensate line – BE
CAREFULL TO AVOID SEVERE
BURNS --.Condensate will drain from
the coil system initially, but the flow
should stop after a minute or two. If the
flow continues, water is leaking from the
pressurized shell side to the tube side of
the Generator. Disassemble, inspect,
repair (if possible), replace, and
reassemble the Generator as outlined in
the DISASSEMBLY and REASSEMBLY
Sections.
CM12. The Generator coils are scaled up.
Descale the Generator by thermal shock
in the manner outlined under
DESCALING BY THERMAL SHOCK.
CM13. The Generator is being utilized at a rate
higher than its design capacity. Contact
the nearest AERCO Representative for
advice in remedying this problem.