Refuelers are fuel tank trucks equipped with flow metering, control and filtration equipment to deliver fuel to an aircraft.. In comparison, a hydrant cart, which is also equipped with f
Trang 1Manual of Petroleum
Measurement Standards
Chapter 6—Metering Assemblies
Section 4—Metering Systems for Aviation Fueling
Facilities
SECOND EDITION, JANUARY 2007
REAFFIRMED, JANUARY 2012
Trang 3Manual of Petroleum
Measurement Standards
Chapter 6—Metering Assemblies
Section 4—Metering Systems for Aviation Fueling
Facilities Measurement Coordination
SECOND EDITION, JANUARY 2007
REAFFIRMED, JANUARY 2012
Trang 4Users of this Standard should not rely exclusively on the information contained in this ment Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.
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Copyright © 2007 American Petroleum Institute
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6.4.1 INTRODUCTION .1
6.4.2 SCOPE .1
6.4.3 REFERENCES 1
6.4.4 DISPENSING EQUIPMENT .2
6.4.4.1 General 2
6.4.4.2 Design Considerations 2
6.4.4.3 Design Requirements 2
6.4.5 OPERATING GUIDELINES .3
6.4.6 PROVING EQUIPMENT FOR AVIATION FUELING METERS .4
Figures 1a Typical Flow Diagram for a Refueler with Mechanical-type Meter 6
1b Typical Flow Diagram for a Refueler with Electronic-type Meter 7
2a Typical Flow Diagram for a Hydrant Cart with Mechanical-type Meter 8
2b Typical Flow Diagram for a Hydrant Cart with Electronic-type Meter 9
v
Trang 9Chapter 6—Metering Assemblies Section 4—Metering Systems for Aviation Fueling Facilities
6.4.1 Introduction
There are two basic methods of fueling large aircrafts Fuel can be delivered to the aircraft by a refueler, or by a hydrant cart
Refuelers are fuel tank trucks equipped with flow metering, control and filtration equipment to deliver fuel to an aircraft A eler may also be used to de-fuel an aircraft In comparison, a hydrant cart, which is also equipped with flow metering and control equipment, is connected to a hydrant system rather than having an onboard aviation fuel storage tank Hydrant cart is also known
refu-as “dispenser.”
A hydrant system delivers aviation fuel from storage tanks of the airport fueling system to aircraft through a pressurized airport pipeline network The airport fueling system typically consists of the following components:
1 Fuel storage tanks
2 Facilities to receive fuel and to fill storage tanks (receiving station)
3 Facilities for withdrawing fuel from the tanks and distributing it to fueling equipment
4 Hydrant pumps, control valves, and filters (hydrant system)
5 Refeuler fueling equipment:
a Refueler loading equipment
This section of MPMS Chapter 6 is limited to the general requirements of flow metering of aviation fuel as it is either dispensed to
aircraft or used to defuel aircraft
Chapter 7 “Temperature Determination”
Chapter 8.1 “Manual Sampling of Petroleum and Petroleum Products”
Chapter 9 “Density Determination”
Chapter 11 “Physical Properties Data”
Chapter 12 “Calculation of Petroleum Quantities”
Chapter 21.2 “Flow Measurement—Electronic Liquid Measurement”
Other useful API/IP standards on aircraft fueling equipment may be obtained from the following API or joint API/IP publications:API/IP Std 1529 Aviation Fueling Hose
API/IP Std 1542 Identification Markings for Dedicated Aviation Fuel Manufacturing and Distribution Facilities,
Air-port Storage and Mobile Fuelling Equipment
API/IP Spec 1581 Specifications and Qualification Procedures for Aviation Jet Fuel Filter/Separators
API/IP Draft Std 1583 Laboratory Tests and Minimum Performance Levels for Aviation Fuel Filter Monitors
API/IP Spec 1584 Four-inch Hydrant System Components and Arrangements
API/IP 1585 Guidance in the Cleaning of Airport Hydrant Systems
API/IP Spec 1590 Specifications and Qualification Procedures for Aviation Fuel Microfilters
Trang 102 C HAPTER 6—M ETERING A SSEMBLIES
6.4.4 Dispensing Equipment
6.4.4.1 GENERAL
A refueler is a vehicle equipped with tank, pumps, hoses, hose rail, filters, separators (or filter monitors), flow meter and other accessories required to deliver fuel to an aircraft (see Figures 1a and 1b) The refueler, after being loaded with fuel at a loading rack, transports the fuel to the aircraft and loads it A refueler is also typically designed to allow de-fueling of aircraft It then either stores the fuel in its tank or off-loads the fuel to another storage tank
A hydrant cart is used to dispense fuel from the hydrant system to the aircraft through aviation fueling hoses that connect to the aircraft and an inlet hose coupler that connects to a hydrant valve located in a pit near the aircraft fueling position (see Figures 2a and 2b) A hydrant cart is equipped with hoses, filters, meters, valves and other accessories
On a refueler or a hydrant cart, it is essential that all equipment be marked for product identification in accordance with API/IP Std 1542
capac-The larger meter designed to handle the full rated capacity of the fueling unit is installed in a supply line to relatively short delivery hoses installed on a fuel servicing platform for servicing under-wing connections of large commercial aircraft The second meter, and possibly a third, rated at approximately one-half the design flow of the servicer, is installed in a delivery line supplying product to a hose reel or reels used to furnish product to a fueling point remote from the servicer location, such as to the wing fueling points on the opposite side of the aircraft
4 At present, the volume delivered in the majority of fuel sales contracts are at ambient temperature, i.e., they are based on gross observed volume (GOV) However, determination of the gross standard volume (GSV) of the fuel may be used for the purposes of:
a stock reconciliation, and
b calculating the weight of the fuel in some cases
Refer to API MPMS Chapter 12.2 for calculation procedures.
5 Since refuelers operate at relatively low pressure, a pressure sensor onboard a refueler can be ignored with little effect on accuracy However, hydrant carts are operated at the elevated line pressure of the hydrant system The effect of pressure on determining the compressibility factor, which is used to calculate gross standard volume and/or meter factor, may be required
6 For product quality check, a means for taking a manual line sample at the fueling unit should be provided in accordance
with API MPMS Chapter 8.1 (ASTM D 4057).
6.4.4.3 DESIGN REQUIREMENTS
The following design requirements are normally specified for meters used on aviation fuel dispensers/refuelers:
1 Meters shall be constructed of aluminum, stainless steel, or epoxy-coated steel The use of uncoated ferrous materials should be avoided
2 The number and size of meters to be used depends on the design loading rate
3 Meter performance shall conform to the requirements of Section 6.4.4 Facilities shall be provided in some part of the port fueling system for meters to be volumetrically proved
Trang 11air-S ECTION 4—M ETERING S YSTEMS FOR A VIATION F UELING F ACILITIES 3
4 The meter and totalizer used may be either of the mechanical or electronic type Normally, mechanical totalizers are only used with displacement meters
5 Mechanical type meters will usually be non-temperature compensated and equipped with rate-of-flow indicators and ters reading in gallons (liters) Adequate lighting shall be provided so that counters can be read at night
regis-6 The meter onboard a refueler should be capable of measuring defueled quantities from an aircraft
7 Large-numeral counters or digital displays indicating the quantity delivered, should be provided and should be visible to the operator from the normal fueling stations
8 Aviation fuel meters in both refueling and defeuling services shall have thermowell(s) on the refueling line and fueling line The thermowell should preferably be located within a distance of 30 cm (12 in.) – 50 cm (20 in.) in accor-
de-dance to API MPMS Chapter 7 Where existing equipment design limits, the thermowell may be located further away but
should not exceed 100 cm (40 in.), from the flow meter The thermowell may be used with a portable thermometer to determine the fuel temperature For electronic flow meters, the temperature should be measured by a resistance tempera-ture detector (RTD) If the system is used for fueling and for de-fueling in separate lines, and if the RTD is not located in the common line, then an RTD shall be provided in each line (i.e., one on the fueling line and one on the de-fueling line)
9 An electronic type meter is typically equipped with a flow computer having a digital counter for displaying measured ume and product temperature
vol-10 The electronic flow computer connected to the meter may be able to perform the following functions:
a Calculate and display measured fuel quantities
b Generate fuel quantity delivery transaction record, also known as a meter ticket using a local printer
c Communicate and transfer data remotely to a remote, host computer system Communication may be by hand-held units used for controlling aircraft fueling operations, and transferring data
d Display instantaneous and average temperature of product loaded during aircraft fueling operations
e Store product standard density
f Control product flow using flow control valve
g Store the last meter factor or K factor resulting from meter proving
h Allow for multi-point meter factors or K factors
i Provide security and audit trail
j Record aircraft type, flight number, tail number, destination/origin, time of day, and amount of fuel delivered
11 The pressure sensor is typically installed near the meter Local display by a pressure gauge, or by a pressure indicating transmitter, or by the electronic flow computer is considered sufficient
12 If the metering system operates at extreme cold climate, insulation should be applied at least 5 nominal pipe diameters on either side of the temperature monitoring location if practical
6.4.5 Operating Guidelines
6.4.5.1 Aviation fuel meters should preferably be proved with either a master meter, a pipe prover (including piston type), or a
tank prover, primarily
6.4.5.2 Aviation fuel meters should be proved as often as necessary to insure accuracy For example, many aviation fuel meters
are proved every six (6) months Meters with high throughout may be proved more often
6.4.5.3 Newly installed meters and meters after repair or overhaul should be proved at least every quarter for two consecutive
quarters If the meter demonstrates satisfactory performance (refer to Section 6.4.5.15 on the requirements), the frequency can be relaxed to a normal schedule, for example, once every six (6) months
6.4.5.4 Meters that have been inoperative for a considerable period should be proved prior to use.
6.4.5.5 If there is more than one meter on a refueler or a hydrant cart, each meter shall be proved individually The other meters
on the refueler or hydrant cart should be completely isolated during proving
6.4.5.6 Meters shall be proved under normal operating conditions of temperature, pressure and flow rate.
6.4.5.7 Meters should be proved at normal operating flow rate If the operating condition during proving does not allow this
flow rate to be reached, prove the meter at its maximum achievable flow and the condition noted in the proving report
6.4.5.8 The flow rate during meter proving shall be kept constant, i.e., within ± 10% of its normal operating flow rate.
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6.4.5.9 A meter shall be re-proved if a substantial change occurs in system pressure, e.g., 20% or 175 kPa (25 psi,) whichever
is greater, or the meter has been opened for maintenance
6.4.5.10 If meter accessories are changed, replaced or the meter has been opened for maintenance, or repair, the meter shall be
re-proved prior to being used
6.4.5.11 When using a tank prover, meter proving should be avoided during bad weather (heavy rain or strong winds).
6.4.5.12 Meter proving should be considered invalid if the ambient temperature variation exceeds 5°C (or 9°F) during the
proving
6.4.5.13 The time intervals between proving runs shall be kept to a minimum in order to avoid changes in temperature and
pressure
6.4.5.14 Dynamic Slip Test—This test is used to establish whether a meter experiences an excessive change in meter factor or
K factor at low flow rates relative to those in the normal operating range of the meter After completing the normal meter proving and all calibrator adjustments, perform two (2) consecutive Dynamic Slip Test runs at a flow rate between 15% and 20% of the manufacturer’s maximum continuous flow rate (capacity) The repeatability of the two runs shall not exceed 0.05%
6.4.5.15 Compute the average meter factor for the Dynamic Slip Test runs Compute the Dynamic Slip “Test Difference” by
subtracting the average meter factor during the Dynamic Slip Test from the average meter factor during normal operation If the Dynamic Slip Test difference is greater than 0.2% (0.002), the meter shall be removed from service and designated for mainte-nance
6.4.5.16 The meter may be returned to service with no further action if:
a The meter proving shows acceptable repeatability (0.05% or better)
b The new meter factor, or pre-run error found (on mechanical meter) does not exceed 0.25% (0.0025) from the previous meter factor
c The Test Difference in the Dynamic Slip Test does not exceed 0.2% (0.002)
6.4.5.17 De-fueling operation should not be attempted until the fuel has warmed up to a temperature that will not cause harm to
the metering equipment or cause an out of range problem for temperature sensing devices
6.4.5.18 If a meter is to be stored for long periods of time, it should be filled with lubricating oil to prevent corrosion in
accor-dance with manufacturer’s instructions
6.4.6 Proving Equipment for Aviation Fueling Meters
API MPMS Chapter 4 specifies the general design requirements and operations for provers The following requirements, of which some are also discussed in API MPMS Chapter 4, apply to proving equipment for aviation fuel dispenser and refueler meters
6.4.6.1 Master meters equipped with mechanical registers should be proved (e.g., using a tank prover) for all products and flow
rates at which they will be operated Master meters equipped with pulse generators may be proved using a dynamic prover (e.g., small pipe prover)
6.4.6.2 A master meter shall not be temperature compensated Its reading shall indicate units of volume without corrections 6.4.6.3 A master meter shall have a minimum readout resolution of 0.1 liter (or 0.1 gallon)
6.4.6.4 Master meters shall meet the repeatability and linearity requirements per API MPMS Chapter 4.5
6.4.6.5 Master meters should be protected against damage during transportation, installation and handling.
6.4.6.6 Master meters should not have mechanical adjustment devices If one is fitted, it should be sealed or disengaged 6.4.6.7 A typical master meter proving system consists of:
a Meter with a volume display and an accurate flow rate indicator
b Upstream and downstream isolation valves
c Strainer located before the meter
d Thermometer or RTD
e Pressure gauge or transmitter