Computerized dispenser tester

A method and system for detecting leaks in a fuel dispenser is operative to pneumatically pressurize a selectable one of a vapor recovery portion and a fuel dispensing portion using a compressed air flow. A flowmeter measures the flow rate of the compressed air communicated to the fuel dispenser for pressurization thereof. A processor provides an indication of the leakage condition of the fuel dispenser based upon the pneumatic flow rate measured by the flowmeter which satisfies a pressurization condition for the fuel dispenser, such as maintaining the pressurization level above a threshold value. The flow rate of compressed air needed to maintain this pressurization level is indicative of the leak rate.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to fuel dispensing equipment 
located at vehicle refueling stations, and, more specifically, to a leak 
detection system using compressed air to selectively pressurize the vapor 
recovery portion and fuel dispensing portion of a fuel dispenser to 
evaluate the equipment for leakage problems. 
2. Description of the Related Art 
Refueling stations employ a fuel dispenser typically provided in the form 
of a nozzle-based assembly having a flexible fluid-conveying hose with a 
discharge nozzle at one end that the operator manually activates to 
control the dispensing of fuel. Integrated with the fuel dispenser is a 
vapor recovery system that typically uses a vacuum-assist pump apparatus 
to facilitate the collection of vapor effluents that are displaced from 
the vehicle tank reservoir as liquid fuel is introduced into the tank. It 
is clear in terms of human safety and environmental protection that both 
the vapor recovery and fuel dispensing portions remain structurally intact 
to protect against unwanted fluid loss or vapor release into the 
atmosphere arising from material or structural failures in the equipment. 
The need to sustain a proper level of equipment integrity extends not only 
to components such as seals that function specifically to provide a closed 
system with respect to the fuel and vapor pathways, but extends as well to 
every other component that interacts with or assists in the communication 
of liquid fuel and recovered vapors. A need therefore exists to provide a 
diagnostic apparatus that examines the fuel dispensing equipment and 
enables the testing operator to determine the origin and extent of any 
weakness in the equipment that would allow either fuel or vapor to escape. 
One conventional approach to identifying leakage problems involves 
measuring the flow rate of the liquid fuel supplied by the fuel pump 
needed to maintain the pressurization of the fuel line within a certain 
range. The leak test performed in accordance with this approach is 
conducted during normal operation of the fuel delivery system. Another 
approach involves isolating a segment of the fuel delivery pipeline and 
determining whether leakage has occurred by measuring any pressure changes 
in the liquid fuel contained in the isolated pipeline segment. Yet another 
conventional leak detector utilizes a test reservoir filled with fuel and 
which is disposed in fluid communication with the fuel line. Monitoring 
pressure and temperature changes in the test reservoir provides data 
indicative of the leak rate of the fuel line. 
These conventional apparatus attempt to identify leaks in the fuel delivery 
system by analyzing the in-line liquid fuel for changes in characteristic 
parameters such as pressure and temperature. This form of analysis 
typically requires activation of the fuel delivery system, particularly 
the fuel pump, so that the fuel line can be pressurized and thereby 
readied for the diagnostic leak test. Performing a leak detection test on 
in-service fuel dispensing equipment, however, presents the obvious 
drawback that fuel is still permitted to escape even though the leak may 
be successfully detected. Other conventional test apparatus operate on the 
fuel delivery system when it is inactivated, although such apparatus are 
still characterized by the need to pressurize the fuel line under 
investigation through simulation or by utilizing a test reservoir. What is 
therefore needed is a diagnostic method and apparatus that allows the fuel 
delivery system to be probed for leaks during an inactivation period and 
that does not require the fuel line to be pressurized with fuel in order 
for the leak test to be conducted. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a system and method 
for detecting leaks in the fuel delivery system associated with a 
refueling service station. The leak detection system is preferably 
provided in the form of test equipment including a means for pneumatically 
pressurizing a selectable one of a vapor recovery portion and a fuel 
dispensing portion of the fuel delivery system. For this purpose there is 
provided a fluid source that controllably generates a pressurized fluid 
flow preferably comprised of pressurized air. A coupling arrangement 
preferably provided in the form of a valve assembly disposes the 
pressurized fluid source in fluid communication with the fuel delivery 
system. A measurement means provided in the form of a flowmeter measures 
the flow rate of the compressed air generated by the fluid source and 
communicated to the fuel delivery system for pressurization thereof. A 
controller is provided to control the pressurization activity of the test 
equipment. An analysis means provides an indication of the leakage 
condition of the fuel dispensing system based upon the pneumatic flow rate 
measured by the flowmeter which satisfies a pressurization condition for 
the fuel dispenser. This pressurization condition, in one form thereof, 
involves maintaining the pressurization level of the selected fuel 
dispenser portion above a threshold value. The flow rate of compressed air 
needed to maintain this pressurization level is indicative of the leak 
rate. 
The invention, in one form thereof, comprises a leak detection system for 
use with a fuel dispenser. The leak detection system includes a 
pressurization means for pneumatically pressurizing at least a portion of 
the fuel dispenser; a control means for controlling the pneumatic 
pressurization activity of the pressurization means; a measurement means 
for measuring the pneumatic flow rate associated with the pressurization 
means; and a processor means for providing an indication of the leakage 
condition of the at least a portion of the fuel dispenser based upon the 
pneumatic flow rate measured by the measurement means which satisfies a 
pressurization condition for the fuel dispenser. 
The pressurization means, in one form thereof, is operable to controllably 
pneumatically pressurize at least one of a vapor recovery portion and a 
liquid fuel dispensing portion of the fuel dispenser. The pressurization 
means, in another form thereof, further comprises a fluid source means, 
disposed in operative fluid communication with the at least a portion of 
the fuel dispenser, for controllably generating a pressurized fluid flow. 
The control means, in one form thereof, further includes a pressure sensor 
adjustably arranged in pneumatic pressure-detecting relationship with the 
at least a portion of the fuel dispenser; and a means for generating a 
control signal representative of the pneumatic pressure detected by the 
pressure sensor and providing the control signal to the fluid source means 
to effect control thereof. The pressurization means further includes a 
controllable valve assembly arranged with the fluid source means and 
responsive to valve control signals supplied by the control means to 
controllably regulate the flow of pressurized fluid generated by the fluid 
source means and communicated to the at least a portion of the fuel 
dispenser. The measurement means, in one form thereof, further includes a 
fluid flow sensor adjustably arranged in flow rate-detecting relationship 
with the pressurized fluid generated by the fluid source means; and a 
means for generating a control signal representative of the fluid flow 
rate detected by the fluid flow sensor and providing the control signal to 
the processor means. 
The pressurization condition for the fuel dispenser associated with the 
functional activity of the processor means involves, at least in part, 
maintaining the pressurization level of the at least a portion of the fuel 
dispenser above a threshold value. 
The invention, in another form thereof, includes a leak detection system 
for use with a fuel dispenser, such leak detection system comprising: a 
fluid source controllably providing a pressurized fluid flow and 
operatively arranged for fluid communication with at least a portion of 
the fuel dispenser to enable the pressurization thereof; a control means, 
operatively coupled to the fluid source, for controlling the 
pressurization of the at least a portion of the fuel dispenser; a first 
means for determining the flow rate of the pressurized fluid flow provided 
by the fluid source; and a processor means for providing an indication of 
the leakage condition of the at least a portion of the fuel dispenser 
based upon the flow rate determined by the first means which satisfies a 
pressurization condition for the fuel dispenser. 
The fluid source, in one form thereof, is operable to controllably 
pneumatically pressurize at least one of a vapor recovery portion and a 
liquid dispensing portion of the fuel dispenser. The pressurization 
condition for the fuel dispenser associated with the functional activity 
of the processor means involves, at least in part, maintaining the 
pressurization level of the at least a portion of the fuel dispenser above 
a threshold value. 
The leak detection system further includes a valve means, arranged for 
control by the control means, for operatively regulating the flow of 
pressurized fluid from the fluid source to a selected one of the vapor 
recovery portion and the liquid dispensing portion of the fuel dispenser. 
The control means further comprises a microprocessor. The invention, in 
another form thereof, comprises a system for use with a fuel dispenser. 
The system includes a pressurization means for controllably pressurizing 
at least a portion of the fuel dispenser using a pressurized pneumatic 
fluid flow; a control means for controlling the pressurization activity of 
the pressurization means; and a means for determining the leakage rate of 
the at least a portion of the fuel dispenser by measuring the flow rate of 
the pressurized pneumatic fluid flow which satisfies a pressurization 
condition for the fuel dispenser. The pressurization condition involves, 
at least in part, maintaining the pressurization level of the at least a 
portion of the fuel dispenser above a threshold value. 
The pressurization means, in one form thereof, further comprises a means, 
including a controllable valve assembly, for selectively operatively 
communicating the pressurized pneumatic fluid flow provided by the 
pressurization means to at least one of a vapor recovery portion and a 
liquid dispensing portion of the fuel dispenser. The leakage rate 
determining means further comprises a sensor arranged to detect the flow 
rate of the pressurized pneumatic fluid flow provided by the 
pressurization means and communicated to the at least a portion of the 
fuel dispenser; and a processor to provide an indication of the leakage 
rate of the at least a portion of the fuel dispenser based upon the 
measured flow rate associated with the satisfaction of the pressurization 
condition. 
The invention, in another form thereof, includes an assembly operatively 
associated with a fuel dispenser. The assembly comprises: a fluid source 
controllably providing a pressurized pneumatic fluid flow; a coupling 
assembly, including a controllable valve assembly, arranged to enable 
fluid communication between the fluid source and at least a portion of the 
fuel dispenser; a sensor arranged to detect the flow rate of pressurized 
fluid provided by the fluid source; a controller, arranged for operative 
control of the fluid source and the valve assembly, to control the 
pressurization of the at least a portion of the fuel dispenser; and a 
processor to determine a leakage condition of the at least a portion of 
the fuel dispenser based upon the detected flow rate of pressurized fluid 
which satisfies a pressurization condition for the fuel dispenser. The 
pressurization condition for the fuel dispenser involves, at least in 
part, maintaining the pressurization level of the at least a portion of 
the fuel dispenser above a threshold value. 
The coupling assembly is operatively arranged to permit the pressurized 
fluid flow provided by the fluid source to selectively communicate with at 
least one of a vapor recovery portion and a liquid dispensing portion of 
the fuel dispenser. The invention, in yet another form thereof, includes a 
leak detection system for use with a plurality of fuel dispensers. The 
leak detection system comprises: a pressurization means for controllably 
selectively pressurizing at least one of the plurality of fuel dispensers 
using a pressurized fluid flow; a control means for controlling the 
pressurization activity of the pressurization means; a measurement means 
for measuring the flow rate of the pressurized fluid flow provided by the 
pressurization means; and a processor means for providing an indication of 
the leakage condition of the at least one of the plurality of fuel 
dispensers subject to pressurization based upon the flow rate measured by 
the measurement means which satisfies a pressurization condition for the 
at least one fuel dispenser. The pressurization condition for the at least 
one fuel dispenser involves, at least in part, maintaining the 
pressurization level of the at least one fuel dispenser above a threshold 
value. 
The pressurization means, in one form thereof, further comprises a fluid 
source controllably providing a pressurized fluid flow; and a coupling 
means, arranged for control by the control means and including a 
controllable valve assembly, for operatively establishing fluid 
communication between the fluid source and the at least one of the 
plurality of fuel dispensers. The coupling means is operable to permit the 
pressurized fluid flow provided by the fluid source to communicate with at 
least one of a vapor recovery portion and a liquid dispensing portion of 
the at least one of the plurality of fuel dispensers. 
The invention, in yet another form thereof, comprises a leak detection 
method for use with a fuel dispenser. The method comprises the steps of: 
pneumatically pressurizing a selectable one of a vapor recovery portion 
and a fuel dispensing portion of the fuel dispenser; controlling the 
pneumatic pressurization of the selectable one of the vapor recovery 
portion and the fuel dispensing portion of the fuel dispenser in 
accordance with leak test criteria; measuring the flow rate of the 
pneumatic fluid flow associated with the pneumatic pressurization 
activity; and providing an indication of the leakage condition of the 
selectable one of the vapor recovery portion and the fuel dispensing 
portion of the fuel dispenser based upon the measured pneumatic fluid flow 
rate which satisfies a pressurization condition for the fuel dispenser. 
The pressurization condition for the fuel dispenser associated with the 
step of providing an indication of the leak condition thereof involves, at 
least in part, maintaining the pressurization level of the selectable one 
of the vapor recovery portion and the fuel dispensing portion above a 
threshold value. 
The invention, in still yet another form thereof, includes a leak detection 
method for use with a fuel dispenser. Such method comprises the steps of: 
providing a fluid source controllably supplying a pressurized pneumatic 
fluid flow; disposing the fluid source in an arrangement enabling 
operative fluid communication between the fluid source and a selectable 
one of a vapor recovery portion and a fuel dispensing portion of the fuel 
dispenser to permit controllable pressurization thereof; providing a 
sensor to detect the flow rate of pressurized pneumatic fluid supplied by 
the fluid source; providing a controller to control the pressurization of 
the selectable one of the vapor recovery portion and the fuel dispensing 
portion of the fuel dispenser; and providing an indication of the leakage 
condition of the selectable one of the vapor recovery portion and the fuel 
dispensing portion of the fuel dispenser based upon the flow rate detected 
by the sensor which satisfies a pressurization condition for the fuel 
dispenser. The pressurization condition for the fuel dispenser associated 
with the step of providing an indication of the leak condition thereof 
involves, at least in part, maintaining the pressurization level of the 
selectable one of the vapor recovery portion and the fuel dispensing 
portion above a threshold value. 
The step of disposing the fluid source in the fluid communicative 
arrangement further comprises the steps of: providing a controllable valve 
assembly arranged to regulate the flow of pressurized pneumatic fluid 
between the fluid source and the selectable one of the vapor recovery 
portion and the fuel dispensing portion of the fuel dispenser. 
The invention, in still yet another form thereof, includes a leak detection 
method for use with a plurality of fuel dispensers, such method comprising 
the steps of: pneumatically pressurizing a selectable one of a vapor 
recovery portion and a fuel dispensing portion of at least one of the 
plurality of fuel dispensers; controlling the pneumatic pressurization of 
the selectable one of the vapor recovery portion and the fuel dispensing 
portion of the at least one fuel dispenser; measuring the flow rate of the 
pneumatic fluid flow associated with the pneumatic pressurization 
activity; and providing an indication of the leakage condition of the 
selectable one of the vapor recovery portion and the fuel dispensing 
portion of the at least one fuel dispenser based upon the measured 
pneumatic fluid flow rate which satisfies a pressurization condition for 
the fuel dispenser. 
One advantage of the present invention is that the diagnostic equipment 
operates free of any need to pressurize the fuel delivery system with 
liquid fuel, relying instead upon compressed air as the test medium for 
pressurizing the system. 
Another advantage of the present invention is that the diagnostic equipment 
is adaptable to selectively test both the vapor recovery portion and the 
fuel dispensing portion of the fuel delivery system, unlike conventional 
test apparatus that are limited to diagnosing leaks in only the fuel 
dispensing line. 
Another advantage of the present invention is that the leak detection test 
is performed without having to activate any part of the fuel delivery 
system, ensuring that no fuel leakage will occur during the test 
procedure. 
Another advantage of the present invention is that the utilization of 
compressed air to conduct the leak detection test provides an 
environmentally safe testing apparatus, thereby avoiding the use of 
hazardous liquid materials characteristic of conventional systems.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings and particularly to FIG. 1, there is shown in 
block diagram format a leak detection system 10 for use in performing a 
leak detection test on fuel dispensing equipment 12 according to one 
embodiment of the present invention. System 10, in general terms, employs 
a compressed air flow to pressurize a selectable one of a vapor recovery 
portion and a liquid fuel dispensing portion of fuel dispensing equipment 
12 and measures the flow rate of compressed air needed to maintain a 
predetermined pressurization condition within the selected dispenser 
portion, such as a desired pressurization range. This measured flow rate 
is representative of the leak rate of the selected dispenser portion under 
investigation. A coupling arrangement preferably comprising a valve 
assembly is used to controllably connect the source of compressed air to 
any one of a plurality of fuel dispensers such that each of the plural 
fuel dispensers can be selectively examined for leakage. 
The illustrated leak detection system 10 of FIG. 1 includes a pressurized 
fluid source 14 generating a compressed air flow 16. A flowmeter 18 
provides a measure of the flow rate of compressed air flow 16. A 
controllable valve assembly 20 regulates the transmission of compressed 
air flow 16 to fuel dispensing equipment 12, specifically to a selectable 
one of the vapor recovery portion and fuel dispensing portion thereof. A 
connection assembly (not shown) of conventional construction is integrated 
with valve assembly 20 to provide the complete coupling arrangement that 
enables pressurized fluid source 14 to be disposed in operative fluid 
communication with fuel dispensing equipment 12. When fuel dispensing 
equipment 12 incorporates a plurality of individual fuel dispensers, valve 
assembly 20 enables controllable routing of compressed air flow 16 to a 
selected one of the fuel dispensers. 
The leak detection procedure according to the present invention initially 
establishes a certain pressurization level within the selected fuel 
dispenser portion. After the pressurization level is stabilized, the 
illustrated leak detection system 10 continues, if necessary, to supply 
the selected fuel dispenser portion with a compressed air flow 16 to 
ensure that the desired pressurization level is sustained throughout the 
test period. The flow rate of this repressurizing compressed air flow is 
indicative of the leakage rate of the selected fuel dispenser portion. A 
sensor in the form of pressure transducer 22 is provided to monitor the 
pressure within fuel dispensing equipment 12 and generate a pressure 
signal representative thereof. Pressure transducer 22 is interfaced to 
fuel dispensing equipment 12 in a conventional manner. A controller 24 is 
provided to manage, direct, supervise and otherwise control the entire 
operation of leak detection system 10, functioning particularly to 
generate the instructions necessary to execute the leak detection 
procedure according to the present invention. 
Controller 24, in one mode thereof, generates control signals 28 based upon 
the pressure signal 26 supplied by pressure transducer 22 to effect 
suitable control of pressurized fluid source 14 to ensure that a 
sufficient air flow 16 is provided that maintains the air pressure within 
the selected fuel dispenser portion at the predetermined pressurization 
level. A processor 32 provides an indication of the leakage rate 34 based 
upon the flow rate of compressed air 16 needed to maintain the desired 
pressurization level within fuel dispensing equipment 12. As shown, 
processor 32 is arranged to receive the measured flow rate 30 from 
flowmeter 18 to facilitate this determination of leakage rate 34. 
Controller 24 and processor 32 are preferably arranged as an integral unit 
provided in the form of a user-interactive microprocessor or other 
comparable computing arrangement. 
Referring now to FIG. 2, there is shown a flow diagram illustrating a 
sequence of steps for conducting a leak detection procedure according to 
another embodiment of the present invention and which preferably employs 
the leak detection system 10 of FIG. 1 to facilitate execution of the leak 
test. This procedure is preferably associated with a fuel delivery system 
including a plurality of individual fuel dispensers. An initial selection 
is made in step 40 to determine which one of the plural fuel dispensers 
will be designated for the leak detection test. An additional selection is 
made in step 42 to decide whether the vapor recovery portion or the liquid 
fuel dispensing portion of the particular fuel dispenser selected by step 
40 will be subject to pressurization. Based upon the equipment selections 
made in steps 40 and 42, the proper adjustments are made to valve assembly 
20 and fuel dispensing equipment 20 to ensure that the correct fuel 
dispenser apparatus is disposed for fluid communication with the 
pressurized fluid source 14 to enable its pressurization. 
After the system set-up accomplished by steps 40-42-44, the pressurization 
activity commences in step 46 by activating the pressurized fluid source 
14 to thereby generate compressed air flow 16 that is conveyed to the 
selected fuel dispenser portion. This initial pressurization activity is 
discontinued after the pressurization level reaches a certain threshold 
level (as sensed by pressure transducer 22) and remains there for a 
certain holding period. Discontinuing the initial pressurization is 
accomplished by interrupting the flow of compressed air to the fuel 
dispensing equipment as indicated by step 48. Adjustments are then made to 
valve assembly 20 to isolate the as-pressurized fuel dispenser portion so 
that an analysis can be undertaken to determine the leakage rate thereof 
(step 50). In particular, as set forth in step 52, a controlled flow of 
compressed air from fluid source 14 is provided to the as-pressurized fuel 
dispenser portion in accordance with the pressure measurements obtained 
from pressure transducer 22 to maintain a desired pressurization condition 
within the fuel dispenser portion. This pressurization condition, for 
example, may be represented by a predetermined target pressure level that 
is to be sustained throughout the test period. The flow rate of compressed 
air needed to maintain this pressurization condition is then measured 
according to step 54. Although flowmeter 18 may provide a continuous 
reading of the compressed air flow rate, it is preferable to allow the 
pressure level of the fuel dispenser portion to stabilize before 
identifying the particular flow rate measurement that is to be used as the 
basis for determining the leakage rate. The pressure values needed to 
assist controller 24 in controlling fluid source 14 and verifying the 
stabilization condition are provided by pressure transducer 22. 
The flow rate measurement associated with the stabilized pressurization 
level is used by processor 32 to determine the leakage rate (step 56). 
This computed leakage rate is compared against an allowable leakage range 
to determine whether the fuel dispensing equipment should be disabled 
and/or placed out of service due to an unacceptable level of vapor release 
or fuel discharge, whichever is the case. One advantage of using 
compressed air or any other suitable gas as the testing medium relates to 
its non-volatility. Additionally, a gaseous test medium compares favorably 
to a liquid medium because of its ability to better penetrate and pass 
through smaller-dimensioned pores and other leak-producing weaknesses in 
the fuel dispenser, thereby providing an enhanced performance relative to 
the discovery and identification of leakage points. 
Referring now to FIGS. 3-5, there is shown a series of block diagrams 
illustrating one implementation of the leak detection system of FIG. 1. In 
particular, FIGS. 3 and 4 describe the hardware arrangement for the 
illustrated implementation and FIG. 5 shows the valve-based pneumatic 
apparatus used to establish fluid communication between the pressurized 
fluid source and the fuel dispensers under test. The illustrated 
implementation is shown for illustrative purposes only as it should be 
apparent to those skilled in the art that other component arrangements may 
be employed within the scope of the present invention. Furthermore, the 
illustrated implementation is configured for operation in association with 
a four product dispenser (e.g., four grades of fuel) each having a first 
and second side for independent fuel delivery, although any other fuel 
dispenser configuration may be integrally arranged with the leak detector 
system of the present invention. 
Referring particularly to FIGS. 3 and 4, there is shown together by these 
drawings the arrangement of components for constructing one implementation 
of the leak detection system of the present invention. The illustrated 
component arrangement includes, inter alia, a main controller 70; a set of 
input modules 72 providing various types of operator interfaces to the 
system; an array of sensors 74 providing pressure and air flow 
measurements to controller 70; a first valve assembly 76 disposed on the 
fuel dispenser side for controllably regulating the flow of pressurized 
fluid (compressed air) to the liquid dispensing portions thereof; a second 
valve assembly 78 disposed on the fluid source side for controllably 
regulating the flow of pressurized fluid therefrom and for providing 
compressed air to the vapor recovery portion; and a DC solid state relay 
80 for supplying the first valve assembly 76 and second valve assembly 78 
with DC control signals from controller 70. The interconnection and 
arrangement of first valve assembly 76 and second valve assembly 78 is 
shown in the pneumatic apparatus illustrated in FIG. 5. 
Referring to controller 70, the operator interacting with input modules 72 
is alternatively provided with a touch screen 82, a bar code scanner 84, 
and a keyboard 86 for selectively communicating with controller 70 to 
initiate, control, and monitor the leak detection test. Controller 70 
includes various subsystems for interacting with input modules 72 and 
other components of the leak detection system. For example, the 
illustrated controller 70 includes an SVGA video board 88 connected to 
touch screen 82; a touch screen controller 90 for controlling touch screen 
82; and a multi-I/O board 92 communicating with bar code scanner 84 and 
keyboard 86. The illustrated multi-I/O board 92 also provides controller 
70 with connectivity to printer 94 and a serial interface 96, which may 
serve to connect the system to other communication modules, networks, or 
devices. The illustrated controller 70 further includes a digital 
input/output (DIO) board 98 that supplies DC solid state relay 80 with 
control signals for controlling the relevant valve assemblies. An 
analog-to-digital (A/D) board 100 interfaces with A/D multiplexer 102, 
which receives the sensor signals provided by sensor array 74. An Ethernet 
network board 104 permits controller 70 to be configured for communication 
over an Ethernet line. 
Controller 70 is preferably configured in the form of a microprocessor or 
other similar computing module. For example, controller 70 may be a 486DX2 
computer running at 66 MHz with an MS-DOS operating system and having 8M 
of RAM that is located along with the other subsystems in a 10-slot 
industrial chassis. The DIO board 98 may use Computer Boards Inc. 
CIO-DIO192. The analog-to-digital conversion functions may be accomplished 
using Computer Boards Inc. CIO-DAS08-PGM, a MetraByte DAS-8PGA compatible 
board. This board has a 12-bit A/D converter that provides a resolution of 
1/4096 bits of full scale. The solid state relay 80, which is populated 
with DC output modules, is mounted on a solid state relay rack (e.g., a 
24-position relay printed circuit board) and connected to the 192 digital 
I/O board 98 of controller 70 using a 50-pin ribbon cable. A resistance 
measurement is accomplished by using a positive DC voltage, a 1% resistor 
and an input to A/D multiplexer 102. This measurement will be used to 
check the DC resistance of the UDC AC and light AC (transformer and 
ballast resistance) prior to applying the AC voltage. 
The illustrated sensor array 74 includes a flow meter 106 and a set of 
three pressure sensors 108. Flow meter 106 is suitably arranged in a 
conventional manner to establish operative fluid communication with the 
pressurized fluid source (not shown) to enable measurement of the flow 
rate of compressed air generated by the fluid source. Flow meter 106 is 
preferably provided in the form of a gas flow transducer that translates 
0-100 SCCM to a 4-20 Ma proportional output representative of the measured 
flow rate. The transducer has four connections, namely positive and 
negative DC voltage inputs and positive and negative current outputs. The 
current outputs are connected to respective inputs of A/D multiplexer 102 
for transmission to controller 70 for processing thereof. There is a 250 
ohm 1% resistor across the positive and negative air flow transducer 
inputs to A/D multiplexer 102 to convert the air flow sensor signals (4-20 
mA current) into a voltage reading. The pressure sensors 108 are suitably 
arranged in a conventional manner to permit the acquisition of pressure 
readings for the fuel dispenser equipment under test, namely the vapor 
recovery portions and liquid fuel dispensing portions thereof. Pressure 
sensors 108 are each preferably provided in the form of a pressure 
transducer that translates 0-100 psi gauge pressure to a 4-20 Ma 
proportional output representative of the pressure measurement. The 
transducer has two connections, namely a positive DC voltage and a current 
output which is connected to a positive input of A/D multiplexer 102. The 
negative side of a 12 VDC sensor power supply 110 is connected to a 
negative input of A/D multiplexer 102. There is a 250 ohm 1% resistor 
across the positive and negative pressure transducer input to A/D 
multiplexer 102 to convert the pressure sensor signals (4-20 mA) into a 
voltage reading. 
An AC voltage controller 112 supplies controlled AC voltage to the UDC and 
a light matrix through a controllable AC solid state relay 114 that is 
populated with AC input and AC output modules. The AC solid state relay 
114 and DC solid state relay 80 may be provided in the form of an integral 
unit. 
AC controller 112 selects proper voltage to be applied to the dispenser. 
Through a series of relays the UDC can supply 120 VAL or 240 VAL. The AC 
controller 112 also selects the voltage on or off. 
The illustrated first valve assembly 76 and second valve assembly 78 each 
comprise an arrangement of individual valve modules each preferably 
configured in the form of an air-actuated ball valve. Each valve 
configuration includes a ball valve with an air actuator mounted on it and 
pneumatically coupled using a mechanical connection. Ball valves are 
preferred because of their simple open and close characteristics. The 
inflow of air for the actuator is provided by a MAC solenoid, which is 
opened and closed by applying a 24 VDC to the solenoid coil. The MAC 
solenoid, in particular, includes electrical control inputs, a pneumatic 
input port adapted to receive a compressed air flow, and a pneumatic 
output port adapted to supply its associated actuator with the compressed 
air flow. The flow condition of the valve (i.e., open or close) depends 
upon the DC signals present on the solenoid control input lines. The valve 
control signals 118 represent DC inputs to the valves provided in 
accordance with power control signals from controller 70, which direct the 
routing by DC solid state relay 80 of the 24 VDC signal from power supply 
116. 
Referring now to FIG. 5, there is shown in block diagram format the 
arrangement of first valve assembly 76 and second valve assembly 78 
together forming a pneumatic apparatus that selectively establishes fluid 
communication between a fluid source generating a flow of compressed air 
120 and the fuel dispensing equipment. For the illustrated arrangement, 
the applicable testing procedure uses a 20 psi and a 50 psi pressurization 
level. Accordingly, a 20 psi line is provided having a valve arrangement 
that includes an input valve V19 and an output valve V15. Similarly, the 
50 psi line includes an input valve V18 and an output valve V14. The 
output port of each 2-way output valve V14 and V15 is coupled to port 1 of 
3-way high flow rate/bypass valve V17. Valve V17 is coupled at port 2 to 
the input of flow meter 106. The output of flow meter 106 is coupled to 
port 3 of valve V17. The 20 psi and 50 psi lines are used to initially 
pressurize the designated fuel dispenser portion to the indicated pressure 
level, while the flow path through flow meter 106 is used to resupply the 
fuel dispenser portion with a compressed air flow 120 sufficient to 
maintain the pressurized level. The flow rate of this resupplying 
compressed air flow is measured by flow meter 106 and represents the 
leakage rate. For the illustrated example in which the leak detection 
system is operatively associated with a service station having four 
2-sided product dispensers, the illustrated valve arrangement is generally 
configured at its end interfaced with the liquid fuel dispenser such that 
one valve regulates the flow of compressed air into the dispenser inlet 
while a pair of valves each regulates the flow into the dispenser outlet 
associated with a respective side of the fuel dispenser. For example, 
regarding the fuel dispenser delivering the designated Product 1, valve V1 
is connected to the inlet of the associated Product 1 fuel dispenser, 
valve V5 is connected to the outlet corresponding to side A of the 
associated fuel dispenser, and valve V9 is connected to the outlet 
corresponding to side B of the associated fuel dispenser. The inlet 
portion, for example, may correspond to the upstream segment of the fuel 
delivery system connecting the liquid fuel reservoir to the distribution 
point (i.e., where sides A and B branch out), while the outlet portion may 
correspond to the downstream segment of the fuel delivery system extending 
from the distribution point to the manually-activated discharge nozzle, 
which may include the length of flexible fuel delivery hose that is moved 
about by the refueling operator. 
The inlet is the fluid connection from the liquid fuel reservoir to the 
dispenser. The outlet is the fluid connection from the dispenser to the 
device being fueled. The outlet normally has the hose and nozzle coupled 
to the dispenser. 
In operation, the leak test procedure that governs the examination and 
investigation of the fuel dispensing equipment is preferably programmed 
into controller 70 using a software formulation or some other suitable 
format in order to provide an automated test sequence executed under the 
computerized activity of controller 70. As part of a preliminary set-up 
before executing the test sequence, it is necessary that the pneumatic 
apparatus be properly integrated with the fuel dispenser under test. For 
this purpose, the operator may use the bar code scanner 84 to read the 
serial number of the fuel dispenser, which is automatically supplied to 
controller 70. The computer employs a database to cross-reference the 
serial number with the components used to build the fuel dispenser. This 
information allows the operator to make the proper connections (i.e., 
electrical, mechanical, and pneumatic) to the fuel dispenser under test. 
The test sequence can be commenced after the leak detection system is 
operatively integrated with the designated fuel dispensing equipment. 
The test procedure executed by controller 70 broadly includes the following 
sequence of functional steps. Controller 70 directs the pressurization 
activity associated with the fuel dispenser by appropriately controlling 
the operation of the pressurized fluid source and valve assemblies 76 and 
78. The amount of compressed air traveling from the fluid source to the 
fuel dispenser is measured by air flow meter 106 to produce a signal 
representative of the compressed air flow rate. The measurement of 
interest provided by flow meter 106 corresponds to the flow rate needed to 
satisfy a pressurization condition associated with the fuel dispenser. 
This pressurization condition, for example, may relate to maintaining the 
induced pressurization level within the fuel dispenser above or within a 
predetermined threshold range. Since any reduction in air pressure from 
the initial pressurization level represents a loss due to leakage 
(provided that the fuel dispenser is sufficiently sealed and after taking 
into account an acceptable degree of pressure change), the amount of 
compressed air admitted (post-pressurization) into the fuel dispenser must 
indicate the amount escaping from the fuel dispenser. Once the 
pressurization condition is stabilized, which occurs when the 
pressurization level measured by pressure transducers 108 remains steady 
(thereby suggesting that the amount of escaping air is being substantially 
replaced by an incoming flow of compressed air), the reading taken from 
flow meter 106 that accompanies satisfactory achievement of the 
pressurization condition represents the leakage flow rate. If the leak 
rate is below the allowable value the fuel dispenser passes the leak test. 
Otherwise, the fuel dispenser is deemed to have an unacceptable amount of 
leakage and is given a failure rating. A report is printed with the test 
results. The fuel dispenser under test is de-pressurized so that another 
fuel dispenser can be examined. Controller 70 determines on which side the 
product is leaking and whether the leak is on the inlet or outlet side of 
the control valve. Controller 70 is provided with a processor or analyzer 
means to examine the data measurements from flow meter 106 and make the 
determination regarding the leakage rate and its acceptability relative to 
an allowable loss. 
Controller 20 adjusts the fuel dispensing equipment 12 to isolate the inlet 
and outlet. Controller 20, more specifically, adjusts valve V5 and valve 
V9 to determine the source of the leak (V5 and V9 as stated). This 
adjustment is for product 1. Other products use their respective valves. 
Referring now to Appendices A and B attached hereto and forming a part 
hereof, there is provided in Appendix A, a script file defining an 
initialization sequence for making a preliminary check of the leak 
detector system shown and described above in FIGS. 3-5. Appendix B sets 
forth a script file defining a test sequence for selectively performing a 
leak test on the vapor recovery portion of the dispenser and the liquid 
fuel dispensing portion of each one of the four fuel product dispensers. 
The script files serve as general guidelines and may be used as the basis 
for developing a command instruction set that is programmed into 
controller 70 as an execution file. The manner and form of programming may 
be of any conventional type. The script files are for illustrative 
purposes only and should not be considered in limitation of the present 
invention as it should be apparent to those skilled in the art that other 
instruction sequences may be developed to implement the leak detector test 
sequence. For the purpose of explaining the script files, the valve 
settings in the de-energized state are provided for the following valves: 
valves V1 through V13 (ports 1, 3)--discharge; valves V14 and V15 
(normally open)--opened; valve V16 (normally open)--opened; valve V17 
(ports 1, 3)--bypass/high flow meter; and valves V18 and V19 (normally 
closed)--closed. These default settings will allow air pressure to 
decrease (i.e., discharge to atmosphere) when the emergency switch is 
engaged. 
Referring to Appendix A, the script file listed therein is run after the 
computer is initially powered on. The inflow of air generated by the 
pressurized fluid source is checked to verify that it can attain the 
proper pressure levels. The leak detection system is checked to make sure 
that the test operating pressures can be reached and that there are no 
leaks or malfunctioning components in the system. In general, the leak 
detection system is subject to a pre-operational maintenance survey to 
prepare it for executing the leak test procedure. Additionally, the 
pressure is maintained in the air supply tanks to minimize the charge time 
accompanying the actual testing of a fuel dispenser. 
Referring to Appendix B, the listed script file sets forth the instructions 
for implementing the test procedure for both the vapor recovery portion 
and liquid fuel dispensing portion of the fuel dispensers. Each equipment 
model of fuel dispenser has associated with it a particular script file 
stored in a memory area of controller 70. Identification of a model serial 
number by the bar code scanner 84, for example, enables controller 70 to 
retrieve the correct script file and provide the operator with the proper 
instructions for connecting the leak detector system to the fuel 
dispenser. After the proper electrical and pneumatic connections are made, 
the main leak detector test sequence can begin using the retrieved script 
file. 
Reference is now made to the instruction set encompassed by steps 20 
through 40 in the Appendix B script file for describing an illustrative 
sequence of steps associated with the testing of the vapor recovery 
portion of the dispenser, with additional reference being made to the 
valve arrangement of FIG. 5. The discharge valve V16 is first closed. 
Valve V17 is configured for fluid communication between ports 1 and 3 
thereof. The outlet valve V15 associated with the 20 psi line is opened. 
Valve V13, which is arranged for fluid communication at output port 3 
thereof with the vapor recovery portion of the fuel dispenser, is 
activated to permit operational pressurization of the vapor recovery 
portion. After the inlet valve V19 associated with the 20 psi line is 
opened, the compressed air flow 120 follows a fluid transmission path 
through valves V19, V15, V17, and V13 to thereby pressurize the vapor 
recovery portion. Controller 70 controls the pressurization level of air 
flow 120 to make sure that it is supplied at 20 psi. Pressure transducers 
108 monitor the pressurization level of the as-pressurized vapor recovery 
portion to ensure that the pressurizing activity is complete and 
accurately performed. After the initial pressurizing activity is 
completed, the 20 psi line is disabled by closing the inlet valve V19. A 
pressure-maintaining compressed air flow 120 is now provided to the vapor 
recovery portion along a fluid transmission path that passes through valve 
V17 at ports 1 and 2 thereof. Controller 70 actively controls the amount 
of this resupplying air flow in order to sustain the pressurization level 
of the vapor recovery portion in accordance with a test condition, i.e., 
one that involves maintaining the pressurization level at or above the 
original 20 psi mark. The flow rate of this resupplying compressed air 
flow is measured by flow meter 106, which as indicated is disposed in the 
fluid pathway. After the pressurization level of the vapor recovery 
portion is given ample time to stabilize, a flow rate reading is obtained 
from flow meter 106 to provide an indication of the leakage rate. At this 
point the test procedure is completed for the vapor recovery portion and 
the system is returned to its original pre-pressurizing state by suitably 
configuring valves V17, V15 (closed), V16 (opened to facilitate 
discharge), and V13 (ports 1, 3 connected for pressure discharge). 
Reference is now made to the instruction set encompassed by steps 41 
through 83 in the Appendix B script file for describing an illustrative 
sequence of steps associated with the testing of the liquid fuel 
dispensing portion of the product 1 fuel dispenser (sides A and B) at 20 
psi and 50 psi. Valves V1, V5, and V9 are activated to establish fluid 
communication between their respective input and output flow ports (i.e., 
ports 2 and 3). As indicated, the inlet of the product 1 dispenser is 
pressurized through valve V1, while the outlets at sides A and B are each 
pressurized through respective valves V5 and V9. First the 20 psi line and 
then the 50 psi line are operated by properly activating the valve sets 
V19-V15 and V18-V14, respectively, along with controlling the compressed 
air flow 120 to generate the corresponding pressurized flow. For each of 
the 20 psi and 50 psi pressurization sequences, the pressurizing lines are 
closed after reaching the target pressurization level. Next, the flow rate 
needed to stably maintain the respective inlet/outlet liquid fuel 
dispensing portion at the testing pressure level (i.e., 20 psi or 50 psi) 
is measured by flow meter 106 to provide a representative indication of 
the leakage rate. Note that valves V1, V5, and V9 are commonly activated 
so that their respective segments (i.e., inlet/outlet) of the liquid fuel 
dispensing portion are concurrently pressurized. Alternatively, valves V1, 
V5 and V9 may be sequentially activated to serially pressurize the 
inlet/outlet segments and perform the leak test procedure in a discrete 
manner. After the leak test is finished, the valve settings are properly 
readjusted to relieve the pressure from the system. The leak detection 
test involving the fuel dispensers for the other products is executed in a 
similar manner. 
The computerized leak detection system shown and described herein provides 
a fully automated and integrated testing platform, thereby eliminating 
multiple test stations (functional, leak, and vapor recovery) and the need 
for human interpretation of test requirements and results. Data may be 
accumulated in a database resident on controller 70 to create statistical 
information for root cause corrective action. The data may also be 
correlated to equipment serial numbers to allow for the matching of field 
problems to the proper fuel dispenser manufacturer. The leak tests can 
also be performed with a higher degree of efficiency and accuracy due to 
the fully automated implementation available with the computerized 
arrangement. Utilizing compressed air or some other suitable gaseous 
medium provides environmentally safe testing, avoiding the use of 
hazardous liquid materials present in conventional detection apparatus. 
Furthermore, the leak detection system is not model specific but may be 
configurable with any previous, existing or future equipment arrangement 
by simply incorporating the proper connection and interface means using 
any conventionally understood and appropriate technique. 
The leak detector of the present invention can measure leak rate, flow 
rate, and other functional parameters of the dispenser, in particular, 
flow rates through each product, UDC current, light current, valve 
current, motor current, nozzle switches, encoders, keypads, displays, 
printers, card readers, cash acceptors, serial communications, speakers, 
output relays, set manager's mode data may be all monitored. 
While this invention has been described as having a preferred design, the 
present invention can be further modified within the spirit and scope of 
this disclosure. This application is therefore intended to cover any 
variations, uses, or adaptations of the invention using its general 
principles. Further, this application is intended to cover such departures 
from the present disclosure as come within known or customary practice in 
the art to which this invention pertains and which fall within the limits 
of the appended claims. 
APPENDIX A 
______________________________________ 
Initialization Sequence 
______________________________________ 
1. 'example of system test and initialization script file 
2. ' 
3. 'test incoming air pressure 
4. FailureMsg Incoming air pressure should be 75 to 85 PSI 
5. TestPressure PT2&gt;= 75 1'test the incoming air pressure to be 
greater than 75 PSI, wait 1 clock tick 
6. EnergizeDCValve 14 
'close ball valve 14,50 PSI outlet valve 
7. EnergizeDCValve 15 
'close ball valve 15,20 PSI inlet valve 
' 8. 
9. 'test system leak rate at 20 PSI 
10. EnergizeDCValve 16 
'close ball valve 16 
11. DeenergizeDcvalve 15 
'open ball valve 15,20 PSI outlet valve 
12. EnergizeDCValve 19 
'open ball valve 19,10 PSI inlet valve 
13. FailureMsg System test air pressure should be 20 PSI 
14. TestPresure PT1&gt;=20 540' test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
DeenergizeDCValve 19 
'close ball valve 19,20 PSI inlet valve 
16. EnergizeDCValve 17 
'ports 2,3 of V17, measure leak rate 
17. DelayFor 3240 'delay for 3240 clock ticks (3 minutes) to 
'allow system to stabilize 
18. FailureMsg System leak rate @ 20 PSI should be -.2 to +.2 SCCM 
19. 
TestAirFlow M1-.2 .2 
'air flow should be between -.2 and +.2 
'SCCM 
20. EnergizeDCValve 15 
'close ball valve 1,20 PSI outlet valve 
21. DeenergizeDCValve 17 
'ports 1,3 of V17, high flow rate/bypass 
' 22. 
23. 'test system leak rate at 50 PSI 
DeenergizeDCValve 14 
'open ball valve 14,50 PSI outlet valve 
25. EnergizeDCValve 18 
'open ball valve 18,50 PSI inlet valve 
26. 
FailureMsg System test air pressure should be 50 PSI 
27. TestPressure PTI&gt;=50 540' test the pressure at PT1 until it is 
'above 50 PSI for a maximum of 540 clock ticks (30 seconds) 
DeenergizeDCValve 18 
'close ball valve 18,50 PSI inlet valve 
29. EnergizeDCValve 17 
'ports 2,3 of V17, measure leak rate 
30. DelayFor 3240 'delay for 3240 clock ticks (3 minutes) to 
' allow system to stabilize 
31. FailureMsg System leak rate @ 50 PSI should be - .2 to +.2 SCCM 
TestAirFlow M1 -.2 .2 
'air flow should be between -.2 and +.2 
'SCCM 
33. EnergizeDCValve 14 
'close ball valve 14,50 PSI outlet valve 
34. DeenergizeDCValve 17 
'ports 1,3 of V17, high flow rate/bypass 
35. DeenergizeDCValve 16 
'discharge air pressure 
TestPressure PT1&lt;=1 540'make sure the system is de-pressurized 
37. ' system test complete 
______________________________________ 
APPENDIX B 
______________________________________ 
Test Sequence 
______________________________________ 
' example of 428 test script file 
2. ' 
3. The computer will prompt the operator to make the appropriate 
4. electrical, pneumatic connections and turn switches 
5. 'make sure the DC resistance is correct for the selected voltage 
6. FailureMsg UDC AC circuit DC resistance incorrect 
7. TestResistance R1 100 150'measure the DC resistance 
' of the UDC AC circuit 
8. EnergizeACRelay 5 
'switch K5 to connect light AC circuit 
9. TestResistance R1 50 75 
'measure the DC resistance of the light 
AC circuit 
10. DeenergizeACRelay 5 
'switch K5 back to UDC AC circuit 
11. ' 
12. 'set the AC voltage to 110V for both the UDC and lights 
13. 
DeenergizeACRelay 1 
'switch K1 for 110V UDC voltage 
14. DeenergizeACRelay 2 
'switch K2 for 110V light voltage 
15. 
' 
16. 'turn on the AC voltages 
17. 
EnergizeACRelay 3 
'turn on UDC voltage 
18. EnergizeACRelay 4 
'turn on light voltage 
19. ' 
20. 'TEST THE VAPOR RECOVERY PORTION OF 
THE DISPENSER 
21. EnergizeDCValve 16 
'close ball valve V16 
22. DeenergizeDCValve 17 
'ports 1,3 of V17, high flow rate/bypass 
23. DeenergizeDCValve 15 
'open ball valve V15,20 PSI outlet valve 
24. EnergizeDCValve 13 
'ports 2,3 of ball valve V13, charge the 
'vapor recovery of the dispenser. 
25. EnergizeDCValve 19 
'open V19 
26. 
FailureMsg Vapor recovery pressure should be 20 PSI 
27. TestPressure PT1&gt;=20 540'test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
28. DeenergizeDCValve 19 
'close ball valve V19 
29. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
30. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
31. FailureMsg Vapor recovery leak rate @ 20 PSI should 
be &lt;5.0 SCCM 
32. 
TestAirFlow M1 -.2 5.0 
'air flow should be between 
' -.2 and +5.0 SCCM 
33. DeenergizeDCValve 17 
'ports 1,3 of ball valve V17, high flow 
'rate/bypass 
34. EnergizeDCValve 16 
' close V15,20 PSI outlet valve 
35. DeenergizeDCValve 16 
'open ball valve V16, discharge 
36. 
FailureMSG Vapor recovery pressure should drop to &lt;1 PSI 
37. 
TestPressure PT1#=1 540 
'wait for a maximum of 540 clock ticks 
(30 seconds) for the pressure to drop to less than 1 PSI 
38. DeenergizeDCValve 13 
'ports 1,3 of ball valve V13, discharge 
'the vapor recovery 
39. 'THE VAPOR RECOVERY PASSED THE LEAK TEST @ 
20 PSI 
40. ' 
41. 'TEST THE LIQUID PORTION OF THE DISPENSER @ 20 PSI 
42. the computer Will activate the dispenser's manager mode via 
serial communications 
43. EnergizeDCValve 16 
close ball valve V16 
44. DeenergizeDCValve 17 
'ports 1,3 of bali valve V17, high flow 
'rate/bypass 
45. 
' 
46. 'product 1 leak test @ 20 PSI 
47. 
EnergizeDCValve 20 
'close ball valve V20 
48. DeenergizeDCValve 15 
'open ball valve V15,20 PSI outlet valve 
49. EnergizeDCValve 1 
'ports 2,3 of ball valve V1, charge 
'product 1 inlet 
50. 
the computer will open the low flow and high flow valves of side 
A product 1 
51. the computer will open the low flow and high flow valves of side 
B product 1 
52. 
EnergizeDCValve 5 
'ports 2,3 of ball V5, charge side A 
'product 1 outlet 
53. EnergizeDCValve 9 
'ports 2,3 of ball V9, charge side B 
'product 1 outlet 
54. EnergizeDCValve 19 
'open ball valve V19,20 PSI inlet valve 
55. 
FailureMsg Product 1 pressure should be 20 PSJ 
56. TestPressure PT1&gt;= 20 540 ' test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
57. 
DeenergizeDCValve 19 
'close ball valve V19 
58. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
59. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
60. FailureMsg Product 1 leak rate @ 20 PSI should be &lt;5.0 SCCM 
61. TestAirFlow M1 -.2 5.0 
'air flow should be between 
-.2 and +5.0 
62. DeenergizeDCvAlve 17 
'ports 1,3 of ball valve V17, high flow 
'rate/bypass 
63. EnergizeDCValve 15 
'close ball valve V15,20 PSI outlet 
'valve 
64. ' 
65. 'product 1 leak test @ 50 PSI 
66. DeenergizeDCValve 14 
'open ball valve 14,50 PSI outlet valve 
67. EnergizeDCValve 18 
'open ball valve V18,50 PSI inlet valve 
68. FailureMsg Product 1 pressure should be 50 PSI 
69. TestPressure PT1&gt;= 50 540 'test the pressure at PT1 until it is 
'above 50 PSI for a maximum of 540 clock ticks (30 seconds) 
70. DeenergizeDCValve 18 
'close ball valve V18 
71. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
72. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
73. FailureMsg Product 1 leak rate @ 50 PSI should be &lt;5.0 SCCM 
74. TestAirFlow M1 - .2 5.0 
'air flow should be between -.2 
' and +5.0 SCCM 
75. the computer will close the low flow and high flow valves of side 
A product 1 
76. the computer will close the low flow and high flow valves of side 
B product 1 
77. 
DeenergizeDCValve 1 
'ports 1,3 of ball valve V1, discharge 
'product 1 inlet 
78. DeenergizeDCValve 5 
'ports 1,3 of ball valve V5, discharge 
'side A product 1 outlet 
79. DeenergizeDCValve 9 
'ports 1,3 of ball valve V9, discharge 
'side B product 1 outlet 
80. DeenergizeDCValve 16 
'open ball valve 16, discharge to 
'atmosphere 
81. FailureMsg 
82. 
TestPressure PT1&lt;=10 540 'wait for a maximum of 540 clock ticks 
(30 seconds) for the pressure to drop below 10 PSI 
83. EnergizeDCValve 16 
84. ' 
85. 'product 2 leak test @ 20 PSI 
86. 
DeenergizeDCValve 15 
'open ball valve V15,20 PSI outlet valve 
87. EnergizeDCValve 2 
'ports 2,3 of ball valve V2, charge 
'product 2 inlet 
88. 
the computer will open the low flow and high flow valves of side 
A product 2 
89. the computer will open the low flow and high flow valves of side 
B product 2 
90. EnergizeDCValve 6 
'ports 2,3 of ball valve V6, charge side 
'A product 2 outlet 
91. EnergizeDCValve 10 
'ports 2,3 of ball valve V10, charge 
'side B product 2 
92. EnergizeDCValve 19 
'open ball valve V19,20 PSI inlet valve 
93. FailureMsg Product 2 pressure should be 20 PSI 
94. Test Pressure PT1&gt;= 20 540' test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
95. DeenergizeDCValve 19 
'close ball valve V19 
96. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, 
' measure leak rate 
97. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
98. FailureMsg Product 2 leak rate @ 20 PSI should be &lt;5.0 SCCM 
99. TestAirFlow M1 -.2 5.0 
'air flow should be between -.2 
' and +5.0 SCCM 
100. DeenergizeDCValve 17 
'ports 1,3 of ball valve V17, high flow 
'rate/bypass 
101. EnergizeDavalve 15 
'close ball valve V15,20 PSI outlet 
'valve 
102. ' 
103. 'product 2 leak test @ 50 PSI 
104. DeenergizeDCValve 14 
'open ball valve 14,50 PSI outlet valve 
105. EnergizeDCValve 18 
'open ball valve V18,50 PSI inlet valve 
106. FailureMsg Product 2 pressure should be 50 PSI 
107. Test Pressure PT1&gt;= 50 540' test the pressure at PT1 until it is 
'above 50 PSI for a maximum of 540 clock ticks (30 seconds) 
108. 
DeenergizeDCValve 18 
'close ball valve V18 
109. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
110. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
111. FailureMsg Product 2 leak rate @ 50 PSI should be &lt;5.0 SCCM 
112. 
TestAirFlow M1 -.2 5.0 
'air flow should be between 
' -.2 and +5.0 SCCM 
113. the computer will close the low flow and high flow valves of side 
A product 2 
114. the computer will close the low flow and high flow valves of side 
B product 2 
115. 
DeenergizeDCValve 2 
'ports 2,3 of ball valve V2, discharge 
'product 2 inlet 
116. DeenergizeDCValve 6 
'ports 2,3 of ball valve V6, discharge 
'side A product 2 outlet 
117. DeenergizeDCValve 10 
'ports 1,3 of ball valve V10, discharge 
'side B product 2 outlet 
118. DeenergizeDCValve 16 
'open ball valve 16, discharge to 
'atmosphere 
119. FailureMsg 
120. 
Test Pressure PT1&lt;=10 540'wait for a maximum of 540 clock ticks 
'(30 seconds) for the pressure to drop below 10 PSI 
121. EnergizeDCValve 16 
122. ' 
123. 'product 2 leak test @ 20 PSI 
124. DeenergizeDCValve 15 
'open ball valve V15,20 PSI outlet valve 
125. EnergizeDCValve 3 
'ports 2,3 of ball valve V3, charge 
' product 3 inlet 
126. 
the computer will open the low flow and high flow valves of side 
A product 3 
127. the computer will open the low flow and high flow valves of side 
B product 3 
128. 
EnergizeDCValve 7 
'ports 2,3 of ball valve V7, charge side 
'A product 3 outlet 
129. EnergizeDCValve 11 
'ports 2,3 of ball valve V11, charge 
'side B product 3 outlet 
130. EnergizeDCValve 19 
'open ball valve V19,20 PSI inlet valve 
131. 
FailureMsg Product 3 pressure should be 20 PSI 
132. Test Pressure PT1&gt;= 20 540' test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
133. 
DeenergizeDCValve 19 
'close ball valve V19 
134. EnergizeDCValve 19 
'ports 2,3 of ball valve V17, measure 
'leak rate 
135. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
to allow air pressure to stabilize 
136. FailureMsg Product 3 leak rate @ 20 PSI should be &lt;5.0 SCCM 
137. TestAirFlow M1 -.2 5.0 
'air flow should be between 
' -.2 and +5.0 SCCM 
138. DeenergizeDCValve 17 
'ports 1,3 of ball valve V17, high flow 
' rate/bypass 
139. EnergizeDCValve 15 
'close ball valve V15,20 PSI outlet 
valve 
140. 
' 
141. 'product 3 leak test @ 50 PSI 
142. DeenergizeDCValve 14 
'open ball valve 14,50 PSI outlet valve 
143. EnergizeDCValve 18 
'open ball valve V18,50 PSI inlet valve 
144. 
FailureMsg Product 3 pressure should be 50 PSI 
145. Test Pressure PT1&gt;= 50 540' test the pressure at PT1 until it is 
'above 50 PSI for a maximum of 540 clock ticks (30 seconds) 
146. 
DeenergizeDCValve 18 
'close ball valve V18 
147. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
148. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
149. FailureMsg Product 3 leak rate @ 50 PSI should be &lt;5.0 SCCM 
150. 
TestAirFlow M1 -.2 5.0 
'air flow should be between -.2 and +5. 
'SCCM 
151. 
the computer will close the low flow and high flow valves of side 
A product 3 
152. the computer will close the low flow and high flow valves of side 
B product 3 
153. 
DeenergizeDCValve 3 
'ports 1,3 of ball valve V3, discharge 
'product 3 inlet 
154. DeenergizeDCValve 7 
'ports 1,3 of ball valve V7, discharge 
'side A product 3 outlet 
155. DeenergizeDCValve 11 
'ports 1,3 of ball valve V11, discharge 
'side B product 3 outlet 
156. DeenergizeDCValve 16 
'open ball valve 16, discharge to 
'atmosphere 
157. FailureMsg 
158. Test Pressure PT1&lt;=10 540'wait for a maximum of 540 clock ticks 
' (30 seconds) for the pressure to drop below 10 PSI 
159. EnergizeDCValve 16 
160. ' 
161. 'product 4 leak test @ 20 PSI 
162. 
DeenergizeDCValve 15 
'open ball valve V15,20 PSI outlet valve 
163. EnergizeDCValve 4 
'ports 2,3 of ball valve V4, charge 
'product 4 inlet 
164. 
the computer will open the low flow and high flow valves of side 
A product 4 
165. the computer will open the low flow and high flow valves of side 
B product 4 
166. 
EnergizeDCVAlve 8 
'ports 2,3 of ball valve V6, charge side 
'A product 4 outlet 
167. EnergizeDcvAlve 12 
'ports 2,3 of ball valve V12, charge 
'side B product 4 outlet 
168. EnergizeDCValve 19 
'open ball valve V19,20 PSI inlet valve 
169. 
FailureMsg Product 4 pressure should be 20 PSI 
170. Test Pressure PT1&gt;= 20 540' test the pressure at PT1 until it is 
'above 20 PSI for a maximum of 540 clock ticks (30 seconds) 
171. 
DeenergizeDCValve 19 
'close ball valve V19 
172. EnergizeDCValve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
173. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
174. FailureMsg Product 4 leak rate @ 20 PSI should be &lt;5.0 SCCM 
175. TestAirFlow M1 - .2 5.0 
'air flow should be between 
' -.2 and +5.0 SCCM 
176. DeenergizeDCValve 17 
'ports 1,3 of ball valve V18, high flow 
'rate/bypass 
177. EnergizeDCValve 15 
'close ball valve V15,20 PSI outlet 
'valve 
178. ' 
179. 
'product 4 leak test @ 50 PSI 
180. DeenergizeDCValve 14 
'open ball valve 14,50 PSI outlet valve 
181. EnergizeDCValve 18 
'open ball valve V18,50 PSI inlet valve 
182. 
FailureMsg Product 4 pressure should be 50 PSI 
183. Test Pressure PT1&gt;= 50 540' test the pressure at PT1 until it is 
'above 50 PSI for a maximum of 540 clock ticks (30 seconds) 
184. 
DeenergizeDCValve 18 
'close ball valve V18 
185. EnergizeDavalve 17 
'ports 2,3 of ball valve V17, measure 
'leak rate 
186. DelayFor 3240 'wait for 3240 clock ticks (3 minutes) 
'to allow air pressure to stabilize 
187. FailureMsg Product 4 leak rate @ 50 PSI should be &lt;5.0 SCCM 
188. TestAirFlow M1 -.2 5.0 
'air flow should be between 
' -.2 and +5.0 SCCM 
189. 
the computer will close the low flow and high flow valves of side 
A product 4 
190. the computer will close the 10W flow and high flow valves of side 
B product 4 
191. 
DeenergizeDCValve 4 
'ports 1,3 of ball valve V4, discharge 
' product 4 inlet 
192. DeenergizeDCValve 8 
'ports 1,3 of ball valve V8, discharge 
'side A product 4 outlet 
193. DeenergizeDCValve 12 
'ports 1,3 of ball valve V12, discharge 
'side B product 4 outlet 
194. DeenergizeDCValve 16 
'open ball valve 16, discharge 
195. 
FailureMsg 
196. Test Pressure PT1&lt;=1 540 ttest the pressure at PT1 until it is 
'below 1 PSI for a maximum of 540 clock ticks (30 seconds) 
197. 'THE DISPENSER PASSES THE LEAK TEST 
198. ' 
199. 'turn off the AC voltages 
200. 
DeenergizeAcRelay 3 
'turn off UDC voltage 
201. DeenergizeACRelay 4 
'turn off light voltage 
202. 
The computer will generate a report indicating the results of the 
test. 
203. The computer will prompt the operator to disconnect the 
appropriate electrical and pneumatic connections 
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