Table of Contents
Advertisement
d. Dismount the low water cutoff control from the
probe.
e. Unscrew the probe from the boiler tapping.
f. Inspect that portion of the probe that is exposed
to the boiler water for a scale or sediment
buildup.
g. Light deposits may be removed by wiping the
probe with a damp cloth. Wiping the probe with
a cloth soaked in vinegar will remove more
tenacious lime deposits. The most stubborn
deposits may be removed from the probe by
using a diluted amount, 3 parts of water to 1
part of phosphoric acid (H
CAUTION
Exercise caution when handling phosphoric acid
and follow the instruction label on its container.
h. Clean the pipe threads of the probe to remove
old, hardened pipe dope and other foreign
matter.
i. Apply a moderate amount of good quality pipe
dope to the pipe threads on the probe, leaving
the two end threads bare. Do not use PTFE
(Teflon) tape.
j. Screw the probe into the boiler tapping.
k. Mount the low water cutoff control on the probe.
l. Reconnect the control to probe wiring.
m. Fill the boiler to its normal waterline.
n. Add boiler water treatment compound as needed
(refer to paragraph N.).
o. Restore electric service to the boiler.
p. Fire burner to bring the water in the boiler to a
boil to drive off free oxygen.
q. WARNING — BEFORE RETURNING
BOILER TO SERVICE: Follow the low water
cutoff check out procedure in step L.4..
2. FLOAT TYPE LOW WATER CUT-OFF
During the heating season, if an external low water
cutoff is on the boiler, the blow off valve should be
opened once a month (use greater frequency where
conditions warrant), to flush out the sediment
chamber so the device will be free to function
properly.
Low-water cutoffs and water feeders should be
dismantled annually by qualified personnel, to the
extent necessary to insure freedom from
obstructions and proper functioning of the working
parts. Inspect connecting lines to boiler for
accumulation of mud, scale, etc., and clean as
PO
).
2
4
25
required. Examine all visible wiring for brittle or
worn insulation and make sure electrical contacts
are clean and that they function properly. Give
special attention to solder joints on bellows and
float when this type of control is used. Check float
for evidence of collapse and check mercury bulb
(where applicable) for mercury separation or
discoloration. Do not attempt to repair mechanisms
in the field. Complete replacement mechanisms,
including necessary gaskets and installation
instructions are available from the manufacturer.
N. BOILER AND SYSTEM CLEANING
INSTRUCTIONS FOR TROUBLE FREE
OPERATION.
1. STEAM BOILERS
a. Oil, greases & sediments which accumulate in a
new boiler and piping must be removed from the
system in order to prevent an unsteady water
line and carry over of the water into the supply
main above boiler.
Operate the boiler with steam in the entire
system for a few days allowing the condensate to
return to the boiler. If the condensate can
temporarily be wasted, operate boiler only for
the length of time it takes for condensate to run
clear. If the latter cannot be achieved or if the
condensate is returned to the boiler, boil out the
boiler using the SURFACE BLOWOFF
connection, see Figure 4.
i.
Drain boiler until 1" of water is visible in
gauge glass. Run temporary 1½" pipe line
from the surface blowoff connection to an
open drain or some other location where hot
water may be discharged safely. Do not
install valve in this line.
ii. Drain about 5 gallons of hot water from
boiler into a container and dissolve into it
an appropriate amount of recommended
boil out compound. Remove safety valve &
add solution to boiler water thru exposed
tapping using a funnel.
NOTICE
Check with local authorities or consult local
water treatment services for acceptable chemical
cleaning compounds.
iii. Start burner and operate sufficiently to boil
the water without producing steam pressure.
Boil for about 5 hours. Open boiler feed
pipe sufficiently to permit a steady trickle of
water from the surface blowoff pipe.
Hide quick links:
Advertisement
Table of Contents
