Blowing Off A Steam Boiler - Slant/Fin Galaxy GXH-300H Installation And Operating Instructions Manual

GALAXY
5. Fittings
6. Instruction sheet and assembly drawing.
7. Steam safety valve and 19 mm (
8. Drain cock.
Assembly above components exactly as shown.
Two 13 mm ( / ") tappings are on right side of boiler for this
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assembly.
Two holes are pre-punched in jackets.
Replacement of Steam Boilers
A. Anytime an older steam boiler is removed from the heating
system and replaced with a new boiler, there are certain
conditions that have to be examined in the heating system.
1. Steam systems have a tendency to develop scale inside
the wet return lines and the boiler. The older the system
the greater the accumulation of scale that can exist inside
the piping. Therefore, it is necessary when replacing a
steam boiler to check the piping for blockage or restric-
tions. Clean or replace the piping as required. (See spe-
cial flushing instructions page 14.)
2. All equipment (air vents, radiation equipment, etc.) in the
steam heating system should be checked for proper
operation. All piping should be checked for proper pitch.
3. It is good engineering practice to repack or tighten the
packing nuts on all valves in the heating system.
BLOWING OFF A LOW PRESSURE STEAM BOILER
A. MODELS THAT HAVE NO TANKLESS HEATER OR NO
PROVISION FOR HEATER
1. Those models without tankless heaters or provision for
tankless heaters have a skimmer giving the advantages of
a surface blow pipe, that has been built into the casting to
insure rapid skimming of oil and grease through a 19 mm
( / ") N.P .T. tapping located on the right hand jacket side
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4
panel, 217 mm (8 / ") from the top and 337 mm (13
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16
from the front of the boiler (see Figure A).
2. Turn off electrical power supply to boiler. Allow boiler to
cool down and steam pressure to reduce to zero before
removing skimmer tapping plug. Check for steam pres-
sure by testing the pop safety valve. Keep your hands
and all parts of your body away from the discharge end of
the safety valve. Drain boiler down 25–51 mm (1"–2")
below skimmer tapping. There will be water in the
skimmer trough. The water might be hot. Remove
FIGURE A
Right side view of Galaxy models that are NOT equipped
with or DO NOT have provisions for tankless heaters.
337 mm (13
19 mm ( / ")
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4
217mm (8
648 mm (25 / ")
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2
NORMAL
OPERATING
WATER LEVEL
/ ") street coupling.
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4
/ ")
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4
START OF SKIMMING
LEVEL —51 mm (2")
BELOW TOP OF GAUGE
GLASS (SEE I.C. ABOVE)
/
9 ")
16
19 mm ( / ") SKIMMER
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4
DRAIN VALVE 90°
skimmer plug slowly and carefully. Install 19 mm (3/4")
skimmer valve, elbow and length of pipe and place a
bucket underneath the open end of the pipe. Cover
bucket with a piece of cloth.
3. Fill boiler slowly until water level is 51 mm (2") from top of
gauge glass. (This is the starting water level for skimming
only.) Fire boiler to produce steam. If the system is heavi-
ly laden with oil, it may be difficult to obtain much more
than a pound or so of pressure. Set the pressure control
at about 48 kPa (7 psi). The higher the steam pressure
you can use, the better and faster the cleaning.
4. As a steam develops, open the SKIMMER drain valve with
caution to skim the oil and film from the top of the water.
DO NOT open the boiler drain valve. Close the skimmer
drain valve when the water level drops to about 127 mm
(5'') from the top of the gauge glass. The water may stop
before the level drops to 127 mm (5'') below the top of the
glass. Refill boiler until water level is again 51 mm (2")
from the top of the gauge glass.
5. Repeat (D) above until all film is skimmed off and the
water settles to a desired normal movement. Add makeup
fresh water to the boiler as described in (D) above during
the blow-off operation to maintain the proper skimming
water level in the vessel. Empty bucket frequently in order
to see the difference in water cleanliness.
6. When surging has stopped and water is clean, and no
film can be seen floating in the bucket, shut off boiler,
allow boiler to cool down, drain down to level of skimmer
tapping, remove valve, plug skimmer tapping and refill
the boiler to the normal operating water (648 mm (25
from the bottom of the boiler—see Figure A below).
Check the pop safety valve for proper operation.
7.The entire process may have to be repeated over a period
of a few days on extremely fouled systems.
/ ")
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B. MODELS WITH TANKLESS HEATER OR WITH TANK-
LESS HEATER PLATES ONLY.
1. Turn off electrical power supply to boiler. Allow boiler to
cool down and allow pressure to reduce to zero before
attempting removal of components. Check for steam
pressure by testing safety valve. Keep your hands and
body away from the discharge end of the valve. Remove
FIGURE B
Left side view of Galaxy models that are equipped with or have
provisions for tankless heaters.
648 mm
(25 / ")
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2
NORMAL
OPERATING
WATER
LEVEL
15
/ ")
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2