SERVICE
regulator, dimension A and they should
also both be located one to two smoke
pipe diameters from the breech, dimension B, excluding all elbows, but always
between the breech and draft regulator.
By inserting the stack thermometer in
one hole, steady state conditions will be
proved as soon as possible and leave the
other hole for other tests. Another test
hole must be located preferably within
12 inches over the fire or in the door
closest to fire.
recharge with clean gauge oil.
It has also been found that when draft
gauges respond slowly or are sluggish,
the following components should be
checked:
• leads and probes may be plugged or
leaking;
• pointer may be touching scale;
• shut-off rings on wet-type are leaking air.
With the electronic testers of today, it's
merely a matter of turning it on, Figure 3,
and following the directions.
Checking the smoke tester - insert clean
test paper into instrument. Block off end
of sampling tube. Pull plunger handle
Instruments
Before performing any tests, the instruments must be checked to ensure good
test readings:
Checking the dry-type draft gauge check to be sure that the gauge operates
smoothly, Figure 2. By twirling the hose
end or by inhaling across tube, a negative pressure should register and then
the instrument should return to zero. If
it does not return to zero after a couple
of samples, the instrument is most likely
defective.
Checking the wet-type draft gauge check to be sure that gauge is level and
zeroed.
Check out the same as dry-type gauge.
However, if this instrument does not
return to zero after a couple of samples,
thoroughly clean the instrument and
Figure 2
Figure 3
www.fueloilnews.com | FUEL OIL NEWS | NOVEMBER 2013
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