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9 - Maintenance
Since the boiler 's operation is usually supervised by its automatic controls, conscientious preventative
maintenance should be practiced at all times. Keep the electrical circuitry clean and dry, and all
contacts tight, especially on the magnetic contactors. Do not allow dust or dampness to accumulate
anywhere in the control cabinet. Do not allow the temperature in the control cabinet to exceed 120
deg F. Watch for irregularities in operation and try to catch developing problems early. Perform the
periodic maintenance listed in the following sections at the times given.
Allow only qualified personnel to do maintenance work on this equipment.
9.1-Shift maintenance
1.At some point during each shift, the gauge glass on the water column must be blown down to clear
out any accumulated sediment. Blowdown should be performed during boiler operation.
Gauge glass blowdown
A.Close both top and bottom valves to the gauge fully. B.Open the drain valve on the bottom of the
gauge glass.
C.Open the top valve just enough to lift the disk from its seat, but not enough to cause the ball check
inside the valve to seat.
D.At this point, live steam will be blowing down through the gauge glass and out the drain. Let
blowdown continue for a few seconds (until it becomes apparent that all sediment has been
dislodged from the glass), then fully close the top valve.
E.Close the bottom gauge glass drain.
F.Open the top valve again, just enough to allow a slow passage of pressure. When the flow stops,
open this valve fully.
G.Open the bottom valve to the glass (not the drain) just enough to allow a slow passage of water
into the glass.
H.Let the seepage continue until the water level stabilizes, then slowly open this valve fully.
The above procedure assures a true reading of the gauge glass with both top and bottom valves open.
It is important to make sure that the ball checks in the valves to the gauge glass do not accidentally
seat. If a ball check seats, the gauge glass will no longer reflect the true water volume.
If the boiler shuts down on a high or low water limit and the gauge glass level and all other conditions
are normal, one or both of these ball checks has seated or one of the lines to the gauge glass has
clogged.
2.Blow down the gauge glass of the condensate return tank.
3.Check all hand-operated valves for packing leaks. Check to see that the boiler blowdown, air vent,
condensate tank feed, and drain valves are closed and all others are open.
4.Check the regulating shield travel for responsiveness to hydraulic pump direction change. If it is slug-
gish or unstable, correct the hydraulic pressure.
5.Check to see if the desired pressure is being maintained in the system and boiler.
750-272
Important
!
Electrode Boiler
31
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