Gas Burner Maintenance; Refractory; Casing Seals - CleaverBrooks FLX Operation, Service And Parts Manual

Inspection and Maintenance
G. GAS BURNER MAINTENANCE
Refer to the burner sections for specific information
regarding operation and maintenance of the burner. The
motorized gas valve requires little maintenance, as the
operating mechanism is immersed in oil and completely
sealed. However, proper operation should be checked on a
routine basis.
Keep the outer parts of the valve(s) clean, especially the stem
between the operator and the valve. A nicked, scored, or
otherwise damaged valve stem can cause leakage. Do not
remove dust covers if installed.
The stem packing gland is the O-ring type. If oil is noticed
around the operator base, or if leakage occurs, the valve must
be repaired. If the actuator is sluggish or fails to operate, and
the oil level is known to be correct, the operator portion
should be replaced.
Solenoid Valves
Foreign matter between the valve seat and the seat disc will
cause leakage. Valves are readily disassembled; however,
care must be taken to see that internal parts are not damaged
during removal and that reassembly is in the proper order.
A low hum or buzzing will normally be audible when the
solenoid coil is energized. If the valve emits a loud buzzing
or a chattering noise, check for proper voltage. If voltage is
correct, clean the plunger assembly and interior plunger tube
thoroughly. Do not use any oil. Make sure that the plunger
tube and solenoid are tight when assembled. Take care not to
nick, dent, or damage the plunger tube.
Solenoid coils can be replaced without removing the valve
from the line.
WARNING
! DANGER
Be sure to disconnect the main power
supply to the boiler in order to prevent the
possibility of electrical shock, which could
result in serious personal injury or death.
Check the coil position and make sure that any insulating
washers or retaining springs are reinstalled in the proper
order.
H. REFRACTORY
The boiler is shipped with completely installed refractory.
High temperature refractory lines the burner door and floor of
the boiler. Front and rear walls, side casing panels, the roof
section, the bottom drum and the drum vent are protected
with high temperature insulation. Preventive maintenance
through periodic inspection will keep the operator aware of
750-177
the condition of the refractory and insulation and will guard
against unexpected downtime for repairs.
I. CASING SEALS
The most obvious indication of a problem is the appearance
of discolored paint on the casing or soot and hot gases
escaping at seal joints. It is important that at start-up any
problems are noted and corrected before the boiler is put back
into operation. The following are areas requiring inspection.
Burner Door
Inspect the area around the door and look for discolored paint
or evidence of combustion gas leakage. If a problem is noted
or the door is being opened for scheduled maintenance look
for warped sealing surfaces and make sure that the insulation
on the front wall around the door has not pushed away from
the wall. Cracks may appear in the burner door refractory as
a result of expansion and contraction from operation. If
cracks are larger than 1/8" when the refractory is cooled, the
cracks should be filled with a high temperature bonding air-
dry mortar such as Cleaver- Brooks "Corline."
WARNING
! DANGER
Disconnect main power to the boiler and the
pilot fuel supply to the burner before the
burner door is opened. Electrical power and
fuel supply must remain shut off at all times
when the burner door is open. Failure to
heed this warning could result in serious
personal Injury or death.
Access to the boiler furnace area is gained through the burner
door opening at the front of the boiler. Whenever the burner
is opened, the gasket and gasket surfaces of the burner door
should be inspected. A good seal between the burner door and
the boiler is necessary to prevent leakage of combustion gases
and loss of efficiency. Combustion gas leaks can cause hot
spots with subsequent damage to the burner door and
surrounding refractory. Damaged or hardened gaskets must
be replaced before the burner is put back in operation.
If a new gasket is necessary, remove the old gasket and clean
the gasket surface on the wall and burner door. A spray
adhesive is used to hold the rope gasket in place around the
burner opening. A high temperature silicone may be needed
to seal under the rope gasket at the wall seams. The rope
gasket should wrap around the opening at least two times.
Before the burner door is closed, inspect studs and clean
threads if necessary with 1/2"-13 die. Apply a small amount
of Cleaver-Brooks "Never-Seez" (p.n. 797-1814 or 797-
1816) to the studs. Any nuts that are difficult to thread on
studs should be replaced. Door fasteners should be run in and
tightened evenly to avoid distorting the door or damaging the
Chapter 7
7-7