Review of system operated by Allied Aviation at Reagan National
The Allied Aviation fuel storage facility at Washington’s Ronald Reagan National Airport (DCA) serves 15 commercial carriers and numerous regional airlines sharing the airport’s 45 terminal gates as well as general aviation on the FBO ramp.
Ed
rounsley
Allied Aviation
Located at the south end of the airport grounds, the fuel farm stores jet-A fuel in four 40-foot high by 60- foot diameter fixed roof storage tanks, each with an 820,000 gallon capacity. From there, approximately 75 percent of the fuel is dispensed through an efficient hydrant system to the gate area. The remainder is transported via tanker trucks that fill up at an eight-bay depot feed from the tanks at the storage facility. The Reagan Airport fuel storage facility is one of 16 such tank farms operated by New York - based Allied Aviation, Inc. — 12 operate at major U.S. airports, three in Canada, and one in Puerto Rico. On average, Reagan National Airport serves approximately 1.3 million passengers each month (15.5 million per year) and historically had dispensed more than 550,00 gallons of jet-A fuel daily. Since 9/11, the daily average is closer to 350,000 gallons, according to Allied.
NEED FOR ACCURACY
Accuracy and reliability are paramount for the trouble-free operation
of the storage terminal. The facility, opened at Reagan in June 1994,
incorporates Enraf microprocessor- based servo gauges for monitoring tank
levels and alerting operators to high and low alarm levels. Fuel farm
maintenance manager Ed Rounsley, a 36- year Allied veteran, explains that
the gauges replaced the tape and float system that operated at the old
facility, razed to accommodate the new fuel farm.
"When I first started using them, I tried to prove them wrong," he says. "But after a while I just quit trying. The gauges have proven themselves to be extremely accurate — within the 1/8- inch that can be visibly checked — and we have had virtually no maintenance problems." Each gauge operates within an 8- inch stilling well used to minimize turbulence inside the tank, particularly during delivery. The well also reduces settling time after delivery and dispensing. The gauges rely on an operating principle (Archimedes) in which a displacer, suspended by a stainless wire from the gauge’s housing at the tank roof line, lands on the liquid and changes the weight of the displacer.
Connecting to a sensitive force transducer and using a sophisticated microprocessor, the instrument records infinitesimal level fluctuations. The stated accuracy of the instrument is +/- 0.04-inches, and the gauge has a repeatability of 0.004".
PROTECTION AGAINST
OVERFILL
The Allied facility receives product delivery nightly by pipeline, seven
days a week, pumped from the Plantation Pipeline pumping station 17 miles
away. The tank farm receives Exxon, Motiva, and Crown Petroleum products.
In keeping with Allied’s policy for custody transfer, the tanks are manually
checked by a technician using a dipstick both before and after all field
receptions. The gauges are used as verification during this process. During
normal deliveries, each of the tanks is filled to a height of 37’3". At
that point, the gauge activates a first high-level alarm, transmitting
a signal through the facility’s Programmable Logic Controller (PLC) to
the tank farm’s control room. A visible steady amber light indication
of the alarm for each tank appears on the main monitoring panel in the
control room, accompanied by an audible alarm. As the filling of the tank
proceeds, a second alarm height of 37’6" is reached in which both visual
and audible alarms are triggered by the servo gauge. Delivery is ceased
at this time. The gauge is also used to signal a high-high alarm at 38’3",
if ever required. At this level, the gauge provides dual alarms, an audible
alarm and a steady right light, and activates the automatic shutting of
the open motor-operated tank valves (MOV). This prevents any possibility
of a tank overfill. This level with its attendant alarm system, while
very seldom reached, is checked as part of a semiannual inspection to
verify continued correct operation of the instrument. Setpoints of 3’3"
for a low level alarm and 3’0" for the low-low level alarm are programmed
into the gauge’s memory. At the low level, a steady amber light appears
on the PLC and an audible alarm sounds. Similarly, at the low-low level
setpoint, a steady red light appears and there is an audible alarm. The
MOVs also close at the low-low level. These levels are not as critical
to the facility’s operation and are usually checked only during periodic
tank cleanings. Operating levels, transmitted by the gauge through the
PLC, are continually recorded on an LCD readout at the control panel for
complete inventory management. No ground level indicators are needed at
the base of the individual tanks. Temperature probes are also installed
on the tanks to record the spot product temperature, thereby assisting
the accuracy of the gauge’s volumetric measurement. The homogenous nature
of the product and its frequent mixing minimize the need for any additional
temperature measurement device on the tank.
All-Electric 100LL Refueler Introduced
Air BP Aviation Services recently placed what it terms the "first ever all electric-powered general aviation refueler" into service at the Million Air FBO at Long Beach (CA) Airport. The refueler will be used to distribute 100LL.Air BP Aviation Services president Michael Delk says he foresees the placement of electric refuelers becoming a major focus for his company. Major airports, including those at Los Angeles, San Francisco, and Denver, have mandates requiring all ground service equipment be powered by electric, propane, or CNG by 2010.
The trucks are being produced and put into service through FMI of Portland, OR, and Bosserman Aviation Equipment of Carey, OH.
The Model RF750M-50 truck is built on a low-profile Isuzu chassis and features a 750-gallon tank, a peak 85hp electric motor with manual transmission, and a top speed of 25 mph.
