Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: In order, in a diagnostic unit for leak testing of a tank system of an internal combustion engine, to allow minimization of the energy consumption during a diagnostics test and simultaneously prevent the emission of fuel gases, a sleep/wake-up mechanism is provided. The diagnostic unit enters a sleep mode for a selected time interval after the internal combustion engine is turned off, the diagnostic unit enters a wake-up mode at the end of the first time interval and at least acquires the measurement data necessary for the diagnostics test in the wake-up mode. The diagnostic unit then enters the sleep mode again during the diagnostics period. The diagnostic unit is switched off at the end of the diagnostics period.

Abstract: This invention relates to a recovery boiler as used by the pulp and paper industry burning black liquor, and, more particularly, to a method for rapid detection of tube failures and the location of the affect heat exchanger within the recovery boiler, without need for direct instrumentation, thereby preventing more serious equipment damage, preventing boiler explosion, preventing injury to operators and minimizing repair time on the affected heat exchanger. This method is applicable to Input/Loss methods of monitoring recovery boilers.

Abstract: A meter for monitoring consumption of a resource, such as water or other fluids, and corresponding methods of configuring and operating the meter are disclosed. The meter includes processing and memory devices for determining and storing a supplier measure of consumption of the resource and a communication link for enabling a supplier to access the stored supplier measure. The supplier access is controlled by a first access control device, which prevents unauthorized access to the stored data. The meter further includes a consumer data memory for storing consumer data including a consumer measure of consumption and second access control device. The second access control device enables a consumer to access the stored consumer data without permitting the consumer to modify the stored supplier measure of consumption.

Abstract: A method and apparatus of diagnosing leakage in a fluid power system including a fluid supply line operatively connected to a plurality of valves which are connected to a plurality of actuators. Flow signals generated by a flow sensor disposed in the supply line are processed to obtain fluid consumption over time values and signals used to change the state of the plurality of valves are processes to determine a plurality of episodes. Each of the plurality of episodes corresponds to a pressurization of a particular branch of a particular actuator. The flow signals and the signals used to change the state of the valves are combined to calculate a change in air consumption value for each valve change of state. The change in air consumption values for each episode are compared to a predetermined reference value to determine any deviation corresponding to a particular one of the plurality of episode.

Abstract: Disclosed is a method for measuring leakage flow rate of a valve wherein fluid flows through the valve in a single-phase flow of a gas or steam. The underlying principle upon which the leakage flow rate may be determined is that the heat loss across a length of bare pipe located downstream of the valve causes a decrease in the temperature of the leakage flow. Also disclosed is a method for measuring the leakage flow rate when the fluid passing through the valve transitions from a liquid-phase flow into a two-phase flow of liquid and steam. In two-phase flow, the underlying principle upon which the leakage flow rate may be determined is that any leakage of the valve will cause an increase in the pressure on the downstream side of the valve because of frictional resistance to flow in the downstream piping which corresponds to an increase in temperature thereof.

Abstract: In a method for measuring flow by means of an ultra sonic flow meter, an ultra sonic signal is transmitted in an upstream and a downstream direction. This is measured upon receipt of an ultra sonic signal and the measurement stopped at a stopping point. A first series of transmissions is made, and the starting time of each transmission is incremented or decremented until a time difference between the upstream and downstream signal is inside a reference band. Flow is then calculated in accordance with the time measurements.

Abstract: An apparatus, system and method of establishing a threshold for a leak detection test that is performed on a headspace of a fuel system. A fuel vapor pressure management apparatus includes a housing, a pressure operable device, and a sensor. The housing defines an interior chamber. The pressure operable device separates the interior chamber into first and second portions, and includes a poppet that moves along an axis and a seal that is adapted to cooperatively engage the poppet. A first arrangement of the pressure operable device occurs during the leak detection test when the seal is in a first deformed configuration. A sensor detects the first arrangement of the pressure operable device during the leak detection test. And a processor is coupled to the sensor and reduces sensitivity of the fuel vapor pressure management apparatus during the leak detection test.

Abstract: There is provided a method for detecting and locating leaks in a pipeline network in real-time. A flow model is provided that characterizes flow behavior for at least one of steady and unsteady states respectively corresponding to an absence and a presence of model leaks in the pipeline network, the flow model including a leaking factor kL. A deterministic model is provided to evaluate at least one of a leak status and a no leak status relating to the pipeline network using deterministic criteria. The deterministic criteria is based on a Liapunov Stability Theory. A deviation matrix is constructed based on the flow model and the deterministic model to generate eigenvalues. A leak alarm is generated when at least one of the eigenvalues is less than a predetermined value.

Abstract: Tracking vibrations on a pipeline network includes installing multiple vibration recorders on the pipeline network, with each recorder including a sensor, a timer, a processor, and a digital communication device. At each vibration recorder, vibration signals are received from the sensor at programmed times under the control of the processor of the vibration recorders and processed by the processor. The processed vibration signals are communicated from the vibration recorder to a reader device using the digital communication device. Thereafter, the processed vibration signals from the one or more reader devices are collected at a central computer system. Finally, the collected processed vibrations signals are analyzed at the central computer system to determine abnormal vibration patterns and to obtain measures of any leaks present in the pipeline network.

Abstract: A method for inspecting leakage of a container includes a differential pressure generation step of generating a differential pressure between the inside and the outside of a container; an ozone gas addition step of adding ozone gas to a higher pressure side of the inside and the outside; an ozone concentration detection step of measuring an ozone concentration of a lower pressure side of the inside and the outside; and a leakage determination step of determining presence of the leakage of the container based on a change in the ozone concentration.

Abstract: A method of finding a dip angle in a tilt-compensated electronic compass includes the steps of a) setting a predetermined azimuth angle indicative of a horizontal status of a geomagnetic sensor to a reference azimuth angle; b) if the compass is slightly tilted, stepwise-increasing a dip angle within a predetermined dip angle search range, and calculating azimuth angles associated with individual dip angles; c) comparing the calculated azimuth angles with the reference azimuth angle, and finding one azimuth angle, which is closest to the reference azimuth angle, among the calculated azimuth angles; and d) setting the dip angle applied to the closest azimuth angle to a specific dip angle associated with a corresponding azimuth angle, such that a more accurate azimuth angle can be detected by the on the basis of the calculated dip angle.

Abstract: An apparatus for determining leakage in an evaporated fuel processing system is provided. The evaporated fuel processing system extends from a fuel tank to a purge passage through which evaporated fuel from the fuel tank is purged to an intake manifold of an engine. The apparatus comprises a pressure sensor for detecting a pressure of the evaporated fuel processing system, an atmospheric pressure sensor for detecting an atmospheric pressure, and a control unit connected to the pressure sensor and the atmospheric pressure sensor. The control unit detects a stop of the engine. A determination value used for the leakage determination is corrected according to the atmospheric pressure. The evaporated fuel processing system is closed after the stop of the engine is detected. It is determined whether the evaporated fuel processing system has leakage based on the pressure detected by the pressure sensor and the corrected determination value.

Abstract: The invention is directed to a method for operating an internal combustion engine including an actuating member in an air supply for adjusting an air mass to be supplied to the engine. In the method, a position of the actuating member is adapted to an instantaneous operating state by a short-time adaptation and a position of the actuating member is adapted by a long-time adaptation to compensate for longer term influences on the position of the actuating member. For a long-time adaptation, a long-time adaptation value is formed for the position of the actuating member in dependence upon a minimum short-time adaptation value for the position of the actuating member which was formed during the short-time adaptation. A leakage in the air supply is diagnosed in dependence upon the long-time adaptation value.

Abstract: A method of detecting the location of a failure (e.g., a sudden leak) in a fluid pipeline network, which can be suitably used for estimation of the location of a failure in a water pipeline network, includes the steps of periodically measuring a flow rate or fluid pressure with sensors arranged at a plurality of measuring points along a pipeline in a water pipeline network; comparing a latest measured amount and a previous measured amount at each measuring point to determine if an amount of change at an arbitrary point has exceeded a predetermined value; and calculating a position at which an amount of change becomes maximum, the position being calculated from the magnitudes of the amounts of changes in respective measured values at the time of the detection. The pipeline network may be a water supply and distribution pipeline network which includes a trunk pipeline and branch pipelines.

Abstract: A building protection system includes a switch, a transmitter, a receiver and a controllable shut-off valve disposed within the inlet line of a utility, such as water or gas, provided to a building. The switch is used to close or open the shut-off valve to stop the flow of the utility into the building. The receiver is proximate the valve, while the transmitter and switch are remote from the valve. In one embodiment, the switch is a manual switch that can be used to generate a valve open or a valve closed signal. The switch and transmitter can be wall-mounted, such as in a garage, or can be integrated into a hand-held device, such as a remote control. In other embodiments, the switch is associated with a condition sensor, such as for sensing a utilities leak or for sensing a temperature outside a certain pre-determined limit value.

Abstract: Methods and apparatus are provided for analyzing spacecraft depressurization events. The apparatus comprises a memory configured to store information relating depressurization aperture sizes to feeding volumes and to first derivatives of pressure with respect to time; and information relating to a volume of the at least one compartment. The apparatus further comprises a processor coupled to the memory and configured to receive pressure signals and temperature signals representative of the temperature and pressure in the vessel, detect depressurization from a first derivative of pressure with respect to time calculated in response to the pressure signals, calculate a feeding volume from the compartment volumes, the pressure signals, and the temperature signals and determine a depressurization aperture size using the first derivative of pressure with respect to time responsive to detection of depressurization and the feeding volume.

Abstract: Embodiments of the present invention are directed to providing a leakage detecting method for use in an oxidizing system of forming an oxide layer so as to shorten leakage detecting time period. In one embodiment, a leakage detecting method for use in an oxidizing system of forming an oxide layer comprises performing oxidizing processes on a plurality of test wafers in a plurality of test runs under a specified operating condition in an oxidizing system having an oxidizing chamber to form oxide layers on the test wafers having a plurality of oxide thicknesses for the plurality of test runs by flowing an oxidizing gas through the oxidizing chamber containing the test wafers. An oxygen concentration of the oxidizing gas exiting the oxidizing chamber is measured in each of the plurality of test runs.

Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: A method for the leak testing of a motor vehicle fuel tank and associated evaporative emissions control system is provided. Nitrogen, compressed air or other gases are used to pressurize the system. The time required for pressurization is used to determine the tank headspace volume. The system pressure is then monitored for 120 seconds. The pressure drop in this period is then compared with a pass-fail value cutpoint from a look-up table stored in a computer attached to the testing apparatus. A pass-fail determination is then made. The pass-fail value cutpoint is pre-determined for a specified vapor volume and estimated liquid fuel temperature, as well as time of year, so that systems with leaks larger than a specified diameter consistently fail the test, while systems with leaks smaller than this value consistently pass the test. The test pass-fail criterion is thus compensated for the conditions (tank fill level and fuel temperature, and seasonal variations in fuel volatility) experienced the actual test.

Abstract: A fuel vapor purge system includes a fuel tank, a canister, and an evaporation route, and purges fuel vapor collected in the canister into an intake passage of an internal combustion engine. A failure diagnosis apparatus of the fuel vapor purge system includes a controller having a pressure difference applying unit for applying a pressure difference between the evaporation route and outside air. The controller also detects a level of an influence of the fuel vapor generated in the fuel tank on failure determination of the evaporation route, and detects both a pressure state obtained when the pressure difference applying unit communicates with a reference orifice communicating with the outside air and a pressure state obtained when the pressure difference applying unit communicates with the evaporation route. The failure diagnosis apparatus determines whether there is a failure in the evaporation route in view of the level of the influence by comparing the detected pressure states with each other.

Abstract: In a method and a device for leak testing of a vessel, e.g., a tank venting system of a motor vehicle, a leak-tightness measurement is performed by introducing a positive pressure or partial vacuum and detecting the variation over time of a positive pressure or partial vacuum in the vessel, and a reference measurement is performed using a reference leak. A conclusion is drawn as to the presence of a leak in the vessel by comparing the results of the leak-tightness measurement and the reference measurement. To avoid faulty diagnoses, the positive pressure or partial vacuum during the leak-tightness measurement and the reference measurement is detected by using a single pressure measuring device.

Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: An apparatus and a method for testing the integrity of fuel tanks for leaks are disclosed. A microprocessor controls the pressurization of the fuel tank and then selectively allows the gas within the fuel tank to decay through any leaks within the tank or through the combination of the leaks within the tank and a reference orifice. By computing and comparing the time required for the tank pressure to decay between predetermined pressure levels due to any tank leaks with a standard decay time, a determination can be made whether the leakage rate through the tank is acceptable. Greater resolution, if necessary, is provided by computing the ratio of the time required for the tank pressure to decay between predetermined pressure levels through the combination of any tank leaks and a reference orifice versus only through the tank leaks and compares same against a standard ratio to determine whether the tank leakage rate is acceptable.

Abstract: A method for the leak testing of a motor vehicle fuel tank and associated evaporative emissions control system is provided. Nitrogen, compressed air or other gases are used to pressurize the system. The time required for pressurization is used to determine the tank headspace volume. The system pressure is then monitored for 120 seconds. The pressure drop in this period is then compared with a pass-fail value cutpoint from a look-up table stored in a computer attached to the testing apparatus. A pass-fail determination is then made. The pass-fail value cutpoint is pre-determined for a specified vapor volume and estimated liquid fuel temperature, as well as time of year, so that systems with leaks larger than a specified diameter consistently fail the test, while systems with leaks smaller than this value consistently pass the test.

Abstract: A method monitors the emissions of a supply vessel storing a volatile medium during operation including a fuel supply tank of a motor vehicle. A tightness check of the supply vessel is carried out from time-to-time. The temperature of the medium is determined based on at least one characteristic variable utilizing a model computation from time-to-time or cyclically. Either the temperature is utilized in the tightness check or the tightness check is carried out only when the determined temperature of the medium lies within a pregivable temperature interval.

Abstract: A method and sensor or sensor subsystem permit improved evaporative leak detection in an automotive fuel system. The sensor or sensor subsystem computes temperature-compensated pressure values, thereby eliminating or reducing false positive or other adverse results triggered by temperature changes in the fuel tank. The temperature-compensated pressure measurement is then available for drawing an inference regarding the existence of a leak with reduced or eliminated false detection arising as a result of temperature fluctuations.

Abstract: The invention relates to a method for checking the tightness of a vessel and especially of a tank-venting system of a motor vehicle. In the method, at least a reference leak (42) or the vessel is subjected to an overpressure or underpressure with at least one pressure source. At least one characteristic variable of the pressure source is determined (reference measurement or diagnostic measurement) and these characteristic variables are compared to each other and a conclusion is drawn as to the presence of a leak from the result of the comparison. The pumping power of the at least one pressure source is changed during the reference measurement and/or during the diagnostic measurement.

Abstract: An apparatus and method for detecting a leak in a pipe, the apparatus comprising a sensor (11) located at a pipe (7), configured to detect a signal from the pipe, converter means to convert the signal detected by the sensor into a digital signal, and transform means to transform the digital signal into a different orthogonal space. The apparatus also comprises a transmitter (15) for transmitting the transformed digital signal back to a remote processor.

Abstract: Disclosed is a method for measuring leakage flow rate of a valve wherein fluid flows through the valve in a single-phase flow of a gas or steam. The underlying principle upon which the leakage flow rate may be determined is that the heat loss across a length of bare pipe located downstream of the valve causes a decrease in the temperature of the leakage flow. Also disclosed is a method for measuring the leakage flow rate when the fluid passing through the valve transitions from a liquid-phase flow into a two-phase flow of liquid and steam. In two-phase flow, the underlying principle upon which the leakage flow rate may be determined is that any leakage of the valve will cause an increase in the pressure on the downstream side of the valve because of frictional resistance to flow in the downstream piping which corresponds to an increase in temperature thereof.

Abstract: The invention generally relates to a system and method for integrated gas delivery and leak detection to one or more applications. The system includes at least one application site, a process conduit extending from a process gas source site to the application site, a first and second process flow control at the process conduit, and a first pressure sensor.

Abstract: Systems and methods for monitoring pressurization performance of a cable network that may include detecting alarm conditions within the cable network, recording the time and date during which each alarm condition was initially detected, and calculating a length of time for each detected alarm condition during which the detected alarm condition remains unremediated.

Abstract: An improved method of testing for evaporative emission system leaks monitors vacuum decay in a closed system so that the effects of fuel tank expansion during the test interval are minimized. In a first embodiment pass/fail criteria are established in terms of the time required for the system pressure to decay by a calibrated amount for a predetermined leak size. A leak at least as large as the predetermined leak is detected if the measured time is shorter than a calibrated time. The effects of fuel tank expansion are minimized because the changes in fuel tank volume occur primarily due to the pressure differential across the tank, as opposed to the leak size, and the changes that occur during the test are essentially the same for any leak size under consideration.

Abstract: A system and method for eliminating confusion associated with checking valves, wherein additional test points are added to the measurement of a valve for ensuring the verification of the actual sources of leaks or turbulence. A base line measurement for the valve is established by measuring the level of ultrasonic sound at the two points upstream from the valve. The level of the ultrasound at two downstream points is then measured. The value of the ultrasound at the downstream test points is compared to the values of the ultrasound at the upstream test points. If the values of ultrasound at the downstream test points are higher than the values of the ultrasound at the upstream test points, then the valve is leaking. If the values of the ultrasound at the downstream test points are close to or lower than the values of the ultrasound at the upstream test points, then the valve is not leaking, i.e., the valve is good.

Abstract: In improvements to the Fluid Energy Pulse Test System, apparatus and methods regulate high-pressure, high-fluid-flow-rate energy pulses to generate temperature-controlled transient, ramp, constant-steady-state, and periodic-steady-state fluid-pressure and fluid-flow-rate test data and sound data for evaluating fluid control devices. Transient, ramp, and constant-steady-state performance curves describe dynamic operating characteristics of tested devices. Transient and constant-steady-state pressures and flow rates are precisely defined and compared. Constant fluid conductance is represented by transverse lines on performance graphs. Constant- and periodic-steady-state pressures and flow rates are achieved in less than two seconds. Temperature sensitivity of fluid control devices is determined. Fluid-pressure and fluid-flow-rate data correlated with sound data create audio-visual representations. Three-dimensional amplitude-frequency-time sound signatures are displayed graphically.

Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: The invention relates to a mobile measuring device that monitors potential leaks of gas conduits. The device includes a navigation system.

Abstract: A method for monitoring sound in an in-ground pipeline via at least first and second in-ground acoustic sensors wherein the first in-ground acoustic sensor is in contact with the in-ground pipeline and the second in-ground acoustic sensor is spaced from both the first in-ground acoustic sensor and the in-ground pipeline.

Abstract: An apparatus for determining leakage in an evaporated fuel processing system is provided. The evaporated fuel processing system extends from a fuel tank through a canister to a purge passage through which evaporated fuel from the fuel tank is purged to an intake manifold of an engine. The canister comprises a vent-shut valve that communicates with the atmosphere. The apparatus comprises a pressure sensor for detecting a pressure of the evaporated fuel processing system and a control unit connected to the pressure sensor. The control unit detects a stop of the engine. After the stop of the engine is detected, the control unit closes the vent-shut valve to close the evaporated fuel processing system. The control unit determines whether the evaporated fuel processing system has leakage after the evaporated fuel processing system is closed based on the detected pressure and a predetermined determination value.

Abstract: A flow meter measures a flow rate of fluid flowing through a flow passage based on a duration of propagation of an ultrasonic wave along the flow passage. A signal of the received ultrasonic wave is then compared with a reference voltage to detect an arrival of the ultrasonic wave. A voltage setting unit determines the reference voltage to an appropriate level according to a signal output from a propagation measuring unit which measures a duration of propagation of the ultrasonic wave along the flow passage from the start of transmission of the ultrasonic wave to the output of a signal from a judging unit as the reference voltage being changed. The reference voltage is determined readily and accurately, the flow meter measures the flow rate with the appropriate reference voltage.

Abstract: A method of leak detection in a closed vapor handling system of an automotive vehicle, wherein an engine is shut off, implemented by a system, the method including obtaining a start temperature and start pressure, providing an evaluation temperature, calculating a temperature differential between the start temperature and the evaluation temperature, evaluating whether a pressure switch is closed if the temperature differential is greater than a temperature control value, incrementing a time counter if the pressure switch is not closed and comparing the time counter to a time control value if the pressure switch is not closed.

Abstract: A method of dividing the total leakage losses of a pipe network into intrinsic background leakage and burst leakage, the method comprising: defining a first infrastructure condition factor (ICF) which is a numerical representation of the condition of a network in a threshold good condition in which intrinsic background leakage can assumed to be a negligible proportion of the total network leakage losses; defining a second ICF which is a numerical representation of the condition of a network in a threshold poor condition in which intrinsic background leakage dominates total leakage losses; deriving a network ICF for the network under consideration which expresses the condition of the network as a numerical fraction of the difference between the first and second ICFs; determining total leakage losses from the network by performing a network analysis on the network; and multiplying the total leakage losses by the network ICF to divide the total leakage losses into intrinsic background and total network burst lea

Abstract: The invention relates to a device for detecting a leak between two circuits of a plate-type heat exchanger (1) provided with means for filling two circuits with fluid at a different pressure, characterized in that said device comprises automatic control means for the convergence of the pressure inside said circuits with respect to a given threshold, and means for signalling a leak when the automatic control means have detected the occurrence of said convergence.

Abstract: A mobile leakage detecting device (100) according to the present invention is provided for simplifying detecting operations of a leak portion and enhancing operational efficiency, and is characterized by microphones (3) for detecting ultrasonic waves generated at a fluid leak portion, input means (17) for inputting positional information of the leak portion in a searching area detected based on output signals from the microphones, photograph means (21) for photographing the leak portion, display means (19) for indicating the positional information inputted by the input means (17) and photographed image information (62) of the leak portion obtained by the photograph means (21), and data processing means (17) for relating with one another and storing the output data from the microphones (3), positional information inputted by the input means (17) and photographed image information (62) obtained by the photograph means (21) on the same leak portion.

Abstract: The invention is directed to a system and method for non-invasive pipeline inspection. According to one embodiment, the system includes a processor, an analyzer, and a wave launcher. The wave launcher is adapted to transmit an input wideband waveform having a selected input energy into the pipeline along a longitudinal axis, and to receive from the pipeline a reflected component of the input waveform having a reflected energy. The analyzer is adapted to generate the input waveform, and to receive the reflected component of the input waveform from the wave launcher. The processor is adapted to compare the input waveform with the reflected component of the input waveform to determine characteristics.

Abstract: Embodiments of the present invention are directed to providing a leakage detecting method for use in an oxidizing system of forming an oxide layer so as to shorten leakage detecting time period. In one embodiment, a leakage detecting method for use in an oxidizing system of forming an oxide layer comprises performing oxidizing processes on a plurality of test wafers in a plurality of test runs under a specified operating condition in an oxidizing system having an oxidizing chamber to form oxide layers on the test wafers having a plurality of oxide thicknesses for the plurality of test runs by flowing an oxidizing gas through the oxidizing chamber containing the test wafers. An oxygen concentration of the oxidizing gas exiting the oxidizing chamber is measured in each of the plurality of test runs.

Abstract: This invention relates to a fossil-fired thermal system such as a power plant or steam generator, and, more particularly, to a method for rapid detection of tube failures without direct instrumentation, thereby preventing serious damage to heat exchangers. This method is applicable to Input/Loss methods of monitoring fossil-fired thermal systems.

Abstract: The present invention discloses water leakage detecting system for liquid pipe and method thereof. The present invention provides the present status for all liquid pipes by installing more than one liquid pipes, by laying under the ground, to which more than one conducting wires are inserted or fixed, transmitting pulse signal to each conducting wire using pulse transmitter, checking whether each liquid pipe is damaged or not and grasp the damaged points by inspecting the received signal.

Abstract: Apparatus for testing an emergency valve in which a valve member (10) is movable by fluid-operated actuator (11) between a normal (open or closed) position and an emergency position (closed or open respectively). The apparatus comprises partial stroking means including means (32, 23, 22 to 13) for initiating emergency movement of the valve from its normal towards its emergency position, and means (13, 14) for returning it from a predetermined position intermediate the normal and emergency positions at its normal operating speed. The apparatus includes means for detecting the loss of the controlling electrical signal to the valve and a means (51) for detecting the correct operation of the valve and its associated operating components by measuring the pressure of fluid being released from or being applied to the actuator (11).