Page 232 - Boiler_Operators_Handbook,_Second_Edition

Maintenance 217

of fire and explosion prevention devices to ensure their subjected to a limited number of operating cycles or
reliability. Be certain to incorporate all the applicable re- changes in condition.
quirements in your program. A recommended program Scheduling replacements is not a simple process.
of testing safety devices is included in this book but it You have to have some reasonable degree of expectation
may not contain every requirement you are legally or when the device is going to fail so you are not wasting
contractually required to perform. Keep in mind those money by replacing them too frequently. That’s one of
requirements are only safety related and concentrate the problems with a program that only considers pre-
on devices that were found to contribute to significant ventive maintenance.
failures and warranted investigation due to their cost If you have scheduled operation of equipment that
or loss of life. A system that is as safe as some insurer’s consists of an operating unit and a spare the first failure
and code writers would like is not necessarily reliable provides a basis for determining the life of the other. Of
because it can shut down more frequently. course if you operated them for equal periods of time
Maintenance of stored fuel oil is one item many the probability is the spare unit will fail… right now!
operators forget about because they’re primarily fir- By ensuring operating hours are proportional to the
ing gas. Checking the inventory to be certain the tanks number of pieces of equipment you ensure some time
aren’t leaking and checking for water in the bottom of to operate the remaining piece or pieces before they will
the tanks is critical to ensuring a reliable source of oil fail. Scheduled replacement of spares that have failed
is available if it’s needed. There are additives that can shouldn’t be questioned and you have a reasonable ba-
extend the life of fuel oil in storage and tests for the con- sis for establishing a deadline for the replacement. The
dition of the oil as well, check with your oil supplier. concept here is breakdown maintenance and works well
I have to say it somewhere and this is the only when you have one or two spares to deal with.
place I could conveniently choose. Whenever you pull When you don’t have spares the scheduling of
maintenance on a piece of equipment please, for the replacement of devices is dependent on how critical it’s
sake of yourself and others, please replace the belt or continued operation is. If the decision is yours weigh
coupling guard. Don’t just set it there either. You haven’t the cost of the replacement of all the devices that have a
seen what happens when a loose coupling guard vi- greater than 50% probability of failing between now and
brates around until it’s caught by the coupling bolts and the next maintenance period. Include the cost of labor to
flung across the boiler room at someone. Always replace replace the devices and such contingent costs as dispos-
all the parts, especially protective guards. al expense to establish a reasonable cost for replacement.
The cost of a failure is dependent on the type of facility
served by the boiler plant and can vary dramatically.
REPLACEMENTS A hot water heater in a Boy Scout camp will have a
minimal failure cost, they can use the time spent replac-
I’m regularly called in to provide recommenda- ing the failed heater to train the scouts in providing their
tions when the customer’s management is upset with own hot water. On the other hand, failure of a hot water
repeated failures in an aging boiler plant. A review nor- heater in a hospital borders on unacceptable because
mally results in a recommendation for a major replace- the lack of hot water prevents proper hygiene. The cost
ment program because everything has been ignored and of canceled operations, bringing in food, and possibly
is so worn that it all needs replacement. Frequently it’s relocating patients can all be reflected in the cost of
due to the plant being operated in a manner that ensures failure of a steam boiler. Any production facility will
everything wears out at the same time (see rotating boil- normally have a high cost of failure because the costs
ers in the section on operating modes) a common prac- could include damaged product and loss of sales that
tice that should be avoided. will destroy customer confidence; let alone the high cost
Rotating equipment (fans and pumps) and similar of paying employees when they aren’t making product
devices where movement promotes wear, top the list and securing the facility then restoring it once the re-
of equipment that must be replaced on a regular basis. pairs are completed.
Motorized valves, pressure and temperature switches, If you don’t have a spare you should have a con-
pressure gauges and bi-metal thermometers all have tingency plan in the event of a failure. Possibly you are
moving parts that can wear, gall and fail so they need operating a heating plant for an apartment complex
to be replaced at regular intervals. Those devices can that has only one heating boiler. In the event that boiler
last for years when their use is infrequent and they are fails you have several options but lack of a plan will see