Page 248 - Boiler_Operators_Handbook,_Second_Edition

Consumables 233

leaks. Most of the piping is also installed inside conduit high pressure burner fuel oil supply pumps.
so a leak can be detected. The oil is transferred from trucks to Above-ground
Any UST installed today has to be of a double shell tanks by fuel oil unloading pumps, “unloading pumps”
construction, actually a tank within a tank. Monitoring for short. Those pumps are designed for high volume
of those tanks includes checking the “interstitial space” and low pressure to move the fuel from a typical deliv-
( the space between the two tanks) for signs of leakage. ery truck containing 8,000 gallons to the storage tanks.
That’s leakage either way, fuel oil out or ground water Oil transfer pumps are used to move the oil from one
in. Any tanks of single shell design have to pass a “pet- tank to another and from field tanks to day tanks. An
ro-tite” leak test regularly; those tests are performed by installation with UST’s may have neither of these be-
a licensed third party. cause the truck can drop the oil into the underground
An operator’s responsibility, when it comes to tanks and fuel is drawn from the tanks by the burner
UST’s is monitoring the existing tanks for leaks. That pumps. In some cases fuel is drawn from storage tanks
means that you keep track of the oil. You know how and transferred tank to tank using the burner pumps.
much you had, how much was delivered, how much The pumps used to deliver the stored fuel to the
was burned and, therefore, how much should be in stor- boiler burners are the only ones called fuel oil pumps
age. Storage equals previous quantity plus fuel deliv- even though the others also pump oil. They are tradi-
ered less fuel burned. Then you sound or stick the tanks tionally furnished in a package construction mounted
to determine how much fuel is in them and compare on a steel base that supports the pumps and serves as
that to your calculations. Some modern microprocessor a big drip pan underneath them to catch spills. When
based equipment is available that does all this for you, used for light fuel oil the pumps and a suction strainer
issuing an alarm when a leak is indicated. Regardless are mounted on the base and we call that a “pump set”
of that provision you should know if you have a leak of or “fuel oil pump set.” Heavy oil fired installations in-
any significance. clude some heaters with the pumps to raise the tempera-
Above-ground tanks aren’t exempt from consid- ture of the oil to a proper value for burning and another
eration. There have been many discoveries of leakage strainer with smaller openings in the screen to further
of Above-ground vertical tanks so monitoring them clean the heated oil. The complete assembly with suc-
and testing them on a regular basis is necessary. Above- tion strainer, pumps, heaters, and discharge strainer is
ground horizontal tanks are usually completely above called a “pump and heater set.”
the ground so a leak is apparent. That doesn’t mean you What do we call oil pumps that are mounted on
shouldn’t keep track of the fuel inventory. More than burners and fitted with a connecting shaft to the fan mo-
one Above-ground tank user has discovered mysterious tor? I call them “wrong!” Try not to get stuck with them.
disappearances of oil with no explanation. That’s because At Power and Combustion we used to stock up on fan
some people know they can get away with burning No. wheels before December because of those arrangements.
2 in their diesel vehicles if they’re not too concerned for We sold a lot of new fan wheels every time plants with
injector wear. Most of the heating oil that’s not subjected those pumps had to switch over to oil.
to motor vehicle fuel taxes is now colored red and anyone Those burners are arranged so a short shaft with two
caught with red fuel in their car or truck faces serious coupling halves is inserted in the burner housing inside
fines so that’s not such a problem today. the fan wheel where a matching half coupling receives
One special purpose label we have is “day tank.” one end. The other end of the shaft engages a coupling
That’s a small fuel oil tank which is filled daily from the half on the oil pump which is mounted on the outside of
larger tanks in storage and used to supply the boilers. the fan housing with its shaft through a hole in the hous-
The initial purpose of a day tank was providing a supply ing. You have to practice yoga or something to be able to
of oil heated properly for pumping to the burners. It also get your hands in there and install that shaft properly and
eliminated double piping of oil suction and return to all tighten the set screws that secure the coupling halves. Do
the field tanks (the larger storage tanks). Oil in larger it wrong and the shaft flies off when you start the burner
field tanks was allowed to be much cooler. A day tank with subsequent damage to the fan wheel. We, along with
requires means of filling it from field tanks and accepts other burner representatives, made a lot of money on that
the returned fuel oil from burners that aren’t operating design but I refused to sell the darn things. You want a
and oil relieved from the fuel pump discharge. The day pump set, not one of those monsters.
tank could be heated to supply oil at burning tempera- Heavy oil is not heated to a certain temperature
ture or just heated enough to flow properly through the so the oil is hot enough to burn. It’s heated so it flows