110 results about "Pressure decay" patented technology

Improved integrity test, priming sequence and bag height detection tests, apparatuses and methods for a medical fluid delivery system are provided. The integrity test includes a plurality of air pressure decay tests, using positive and negative pressure. The priming sequence includes pumping fluid through a portion of a patient line to be primed to overcome air in the line and other potential obstacles. The head height test measures a pressure build-up or drop-off within a pump chamber of a membrane pump. The measured pressure corresponds to a head height between a fluid supply and the pump or between the pump and a fluid drain. A determination is made whether the corresponding head height is acceptable.

An implantable blood pressure regulator is provided. The blood pressure regulator includes at least one connection zone and an attenuation zone. The connection zone is suitable for connection to a body conduit, such as a blood vessel. The attenuation zone is movable from a first state to a second state in response to a physiological pressure spikes. The movement from the first state to the second state lowers a level of pressure or dampens a pressure spike in the body conduit.

Fluid leaks can be detected and controlled in a pressurized piping system. Apparatus for this includes control logic; in communication with the logic, a flow detector and/or a pressure detector, and a control valve. One or more of the following is or are provided also: the flow and pressure detectors are both present, and both as single units; the control logic, the flow and/or pressure detector(s) and the control valve are in close proximity to one another; and the control valve has a baseline condition of being shut off. A remote control device can remotely interact with the control logic. Pressure decay and/or flow properties can be employed. The fluid can be water as, for example, in a residential, commercial or institutional system.

Methods and systems for determining whether a catheter malfunction is present in a catheter by analyzing changes in the pressure of fluids being pumped through the delivery lumen of the catheter. The pressure changes that may be monitored may include, e.g., the peak pressure within the catheter and/or the pressure decay profile. The catheter malfunctions that may be determined using the methods and systems of the invention may include, e.g., leaks, blockages, the presence of gas bubbles, etc.

A leak detection system capable of automatically detecting a leak in a pressurized piping system. A pressure decay test is utilized to test for leaks in the piping system. Disruption to users of the piping system is reduced by only performing the pressure decay test when there is no user demand on the piping system. Thus, a leakage test is performed by first determining whether there is user demand on the piping system and proceeding with a pressure decay test only if there is no user demand present. If user demand is initiated during the performance of a pressure decay test, the system detects the user demand and halts the pressure decay test until the user demand stops.

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.

Also included in the system is a microprocessor that is in electronic communication with the flow controls and the first pressure sensor, wherein the microprocessor is programmed to respond to an application standby request by performing a pressure decay test, including closing the second process flow control and pressurizing a portion of the system by opening the first process flow control. Further included in the pressure test is closing the first process flow control when the pressure at the first pressure sensor is at a minimum pressure, and comparing an empirical pressure decay rate at the first pressure sensor with a maximum pressure decay rate, whereby an empirical pressure decay rate that exceeds the maximum pressure decay rate indicates the presence of a leak.

The invention discloses a shale gas reservoir gas diffusion coefficient experiment test method. According to a method, a one-dimensional diffusion mathematic model is built by monitoring pressure attenuation data in a shale plunger rock sample under effective stress conditions of methane gas with a certain initial pressure in a constant-temperature closed system with the micro-pore structure and the gas existence state of a shale reservoir as bases, the diffusion coefficient of the gas (methane) in shale is calculated, and the diffusion mass-transfer capacity of the gas (methane) in the shale is quantitatively assessed. In the experiment testing process, the diffusion process of gas in the shale gas reservoir can be effectively simulated, and influences of effective stress, gas adsorption/desorption and other factors on the diffusion coefficient are reflected. Besides, the method can overcome influences of gas free expansion stage data in a traditional adsorption/desorption method on the diffusion coefficient. The method can assess the diffusion mass-transfer capacity of the gas in the shale and provide experiment support for researches in the aspects of shale gas reservoir productivity models, productivity prediction and the like.

A refracture-candidate diagnostic test is an injection of compressible or slightly compressible fluid such as liquid, gas, or combination at pressures in excess of minimum in-situ stress and formation fracture pressure with pressure decline following injection test recorded to detect a fracture retaining residual width from previous stimulation treatments. The diagnostic consists of small volume injections with injection time being a small fraction of time required for compressible or slightly compressible reservoir fluid to exhibit pseudoradial flow. The fracture-injection portion of a test can be considered as occurring instantaneously, and the results obtained in an open infinite-conductivity hydraulic fracture with pressures above fracture closure stress during before-closure portion of pressure falloff and with pressures less than fracture closure stress during after-closure portion of pressure falloff. Data measurements are transformed into a constant rate equivalent pressure transformation to obtain adjusted pressures or adjusted pseudovariables which are analyzed to identify dual unit-slope before and after closure periods confirming a residual retaining width.

The invention provides a leakage rate estimation system and method for product oil pipelines based on zero dimension and belongs to the technical field of leakage rate detection for the product oil pipelines. The method comprises the following steps: effectively analyzing a lot of data collected on site in a reasonable time, obtaining the state of a whole pipe segment by using a pressure sensor array, and therefore obtaining the pressure changing trend of the pipeline; meanwhile, analyzing whether the pipeline has abnormal conditions or not by adopting a flow balance method and combining with an information consistency theory. The method is visualized and simple, is high in sensitivity and low in false alarm rate and can precisely give an alarm for detection of the small leakage rate and slow leakage. A BP neural network is adopted to calculate the rate of pressure decay of the pipeline, so that the accuracy of the final result is improved. Meanwhile, the method adopting dimensionless modeling decreases the calculated amount and increases the calculation accuracy.

An injector cleaning system for use with an exhaust treatment device is disclosed. The injector cleaning system may have a supply of injection fluid and an injector configured to receive and inject the injection fluid. The injector cleaning system may also have a pressure sensor associated with the injector to generate a signal indicative of the pressure of the injection fluid supplied to the injector. The injector cleaning system may further have a controller in communication with the injector and the pressure sensor. The controller may be configured to determine a pressure decay rate of injection fluid supplied to the injector during a normal injection event based on the signal. The controller may be further configured to compare the determined pressure decay rate to an expected pressure decay rate, and supply cleaning fluid to the injector based on the comparison.

A method for operating an internal combustion engine having a fuel-driven combustion motor, making possible a differentiation of faults in the fuel delivery system. Fuel is delivered under pressure to the combustion motor via a fuel delivery system. A pressure decay rate in the fuel delivery system is determined, and a fault is inferred as a function of a comparison of the pressure decay rate with a predefined threshold value.

An engine of an outboard motor includes a fuel injection system that is configured to increase the accuracy of fuel pressure measurements and more precisely control the amount of fuel injected. In a preferred mode, the fuel injection system can include a pressure dampening device that is connected to the direct fuel injected system. The system can also include a vibration dampening apparatus that protects a pressure sensor from damage that can be caused by engine vibrations.

A wave generation component during an off cycle when the on-off valve is closed to build pressure from the process gas in an accumulation volume. During an on cycle when the on-off valve is open the wave generation component releases the process gas according to a time constant. A flow restrictor installed downstream in a throat of the on-off valve, outputs the rapid square waves to the conduit at a predefined magnitude. The flow restrictor is selected to have an impedance that is high enough to significantly raise the time constant during the on cycle such that pressure decay in each square wave pulse over the on cycle decreases to within a tolerance, wherein the time constant is at least in part a function of the flow restrictor impedance.

A method of analysing a reservoir pressure in an underground formation surrounding a well, comprising: determining the permeability of mud cake on the wall of the well in the region in which the pressure measurement is made; determining the thickness of mud cake on the well of the well in the region in which the pressure measurement is made; determining the hydrostatic pressure in the well in the region in which the pressure measurement is made; measuring the formation pressure at the wall of the well; calculating a pressure decay index from the mud cake permeability and thickness, the hydrostatic pressure and the measured pressure; and using the pressure decay index to analyse the measured pressure to derive the reservoir pressure.

A compressed air system, wherein a decision to de-energize a compressor motor is made with consideration of the likely need for the operation of the compressor at a future point in time. A rate of pressure decay in an air reservoir may be extrapolated over a predetermined time period to predict the need for operation of the compressor within the time period. If operation of the compressor is predicted to be needed within the time period, the compressor is allowed to continue to run in an unloaded mode beyond a normal cool down period.