Repair manual

STEAM GENERATOR (2 PROBE TYPE) MAINTENANCE PROCEDURES
CAUTION: Service on the generator must be performed only by a trained
and experienced service technician, thoroughly familiar with servicing
steam generators. No work should be done on the steam generator while it
is pressurized or hot. Be sure all energy sources are shut off before the
start of any work.
The steam generator must be drained under pressure (blowdown) after a maximum of 8 hours of use. If the generator's
feedwater contains more than 300 parts per million of total dissolved solids, the generator must have a blowdown after each
4-6 hours of use. "Blowdown" means the generator must be drained under pressure.
THE GENERATOR "BLOWDOWN" IS PERFORMED BY SHUTTING OFF THE UNITS RED-LIGHTED "POWER"
SWITCH WHILE THE GENERATOR IS AT NORMAL OPERATING PRESSURE- WHEN THE BOTTOM OF THE
"POWER" ROCKER SWITCH IS PUSHED, ITS RED LIGHT GOES OUT. AND THE DRAIN VALVE
AUTOMATICALLY OPENS. DRAINING THE GENERATOR- AN AUTOMATICALLY-TIMED SOLENOID VALVE
WILL FLUSH THE DRAIN FOR 3 MINUTES. THEN SHUT OFF. AFTER 3 MINUTES, THE UNIT CAN BE
RESTARTED.
Even though the "Blowdown" is performed faithfully each day. it will still be necessary to have a qualified service technician
periodically inspect the inside of the generator for scaling or pitting. The generator's hand hole plate should be removed at
regular intervals, so that it and the inside of the generator can be inspected The hand hole plate should be cleaned and
examined each time it is removed. If the hand hole plate is chipped or cracked, or over three years old, install a new one. A
new hand hole gasket should always be installed.
Scaling indicates a high concentration of dissolved minerals in the feed water. Pitting indicates an excess acid condition. The
best way to reduce servicing time and to assure a long generator life is to provide feed water that is low in mineral content
arid low in gas content Water that is fit to drink can still be high in impurities that are highly detrimental to a steam
generator. Consult the state department of water for an on the premises water analysis and for recommendations concerning
steam generator feed water treatment (if required), in order to remove or reduce harmful concentrations of minerals.
CAUTION: Never tighten the hand hole plate nut when the steam
generator is in use, hot, or otherwise pressurized. Never tighten
nut over 15 foot-pounds torque. Overtightening may cause
uneven stress, which may result in the weakening and possible
breakage of the plate.
The "Blowdown" procedure will not completely remove the mineral deposits that adhere to the top of the
generator.
It will be necessary to periodically have scale accumulations removed from the inside of the steam generator
by a qualified service technician. Only a U.S.D.A. approved acid cleaner should be used to descale the
generator.
Descaling should be done once a year, but in poor water (highly mineralized) areas it may be needed two or three times a
year.
Failure to periodically remove scale from the inside of the generator will result in greatly reduced generator
life.
Check the safety valve once a month while the steam generator is pressurized- Test by pulling the safety valve
lever. The valve must open freely and snap closed when released- If it does not, or if it drips constantly, a new
safety valve is needed.
If the steam generator is to be left idle for three months or more. it should be drained and dried out and the
hand hole plate left off.
CLEVELAND RANGE, INC. 1333 EAST 179
th
ST., CLEVELAND, OHIO 44110
0485 LITHO IN U.S.A. Manufacturer reserves right of design improvement or modification, as warranted.