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This
procedure, or a similar one, should be done at least once a week. The
instructions refer to the diagram. Take the unit out of
service if it fails any of the following tests. Either correct the
problem or replace the defective part.
Failure to follow this procedure will result in a dangerous
condition that could lead to explosion or fire.
- Shut off manual valve [7] downstream of safety shutoff valves.
This traps gas pressure between the safety shutoff valves and manual
valve, causing a flame failure. This
should close the safety shutoff valve [4] and blocking valve
[6]. If both or either valve fails to close, do not proceed
further until you correct the problem.
-
Release gas pressure at test cock [8B] between manual valve
[7] and blocking valve [6], then make bubble test for leak through
blocking valve [6]. If
no leak, close the test cock.
- Release gas pressure at test cock [8A] and bubble test for
leak through safety shutoff [4]. If you don’t find a leak, close
test cock and go to next step. If either valve leaks, correct the
problem and retest 8 to 10 times before proceeding.
- When there are no valve leaks, open manual valve [7] and
relight the burners. Then close manual valve [1]. The safety shutoff
and blocking valve should close due to low gas pressure.
- Relight the burners. Turn high gas pressure switch [5]
setpoint down until it reaches the operating gas pressure. This
should cause the safety shutoff and blocking valves to close for
high gas pressure. Return the setpoint to its original position
before proceeding.
- Shut off the combustion air blower. This should cause a
failure due to low air pressure and cause the safety valves to
close.
- Reset all manual valves to their normal setting for
operation. Make sure all electric valves are operating normally.
Make sure all test cocks are closed before resuming normal
operation.
Alternate Bubble Test
For
a more accurate bubble test, use a water-filled, inverted graduated
glass cylinder 100 cc or larger. Place it in a larger container of
water. If leakage exceeds 8 cc per second, corresponding to 1.0 cfh,
immediately overhaul or replace the valve.
The latest design, materials
and equipment specifications should be obtained from the company
before any reliance is placed on the enclosed since changes may
occur due to product improvement. |
