Description[ edit ] A PV diagram plots the change in pressure P with respect to volume V for some process or processes. Typically in thermodynamics, the set of processes forms a cycleso that upon completion of the cycle there has been no net change in state of the system; i. The figure shows the features of a typical PV diagram. A series of numbered states 1 through 4 are noted.
From Here To There In A Snow-Plowing Chevrolet For maximum efficiency, modern import fuel injection systems require that fuel be delivered at a specified volume and pressure. Of course, fuel volume is required to maintain fuel injection pressure at the fuel injector nozzle.
While a marginally performing Volume and pressure pump might maintain pressure at idle, its effective operating pressure will decrease as engine load increases. Outside factors such as higher ambient air temperatures, ethanol gasoline and inlet filter or screen restrictions may further reduce fuel volume by aggravating the tendency of any fuel pump to cavitate or form bubbles in the pump inlet assembly.
The conventional two-line fuel pump consists of Volume and pressure in-tank mounted pump, an in-line fuel filter mounted on the chassis and a fuel pressure regulator mounted at the end of the fuel injector rail assembly.
Excess fuel is returned through a second fuel line leading from the pressure regulator to the fuel tank. High intake manifold vacuum effectively increases the pressure differential between the fuel rail and fuel injector nozzle.
Consequently, most external fuel pressure regulators use intake manifold vacuum to reduce fuel pressure during high intake manifold vacuum conditions.
In contrast, single-line fuel pumps with integral fuel pressure regulators rely entirely on the PCM modulating fuel injector pulse width to compensate for high vacuum operating conditions. In addition, some applications employ a two-speed fuel pump system to reduce fuel pump noise at low vehicle speeds.
Two-speed systems supply power to the fuel pump through a resistor for low-speed operation and directly to the fuel pump for high-speed operation. In some diagnostic scenarios, a two-speed pump may not switch to high-speed operation and may fail to supply adequate fuel pressure at high engine loads.
Most professional test gauges incorporate a volume test release valve that can be used to release fuel pressure or to provide an approximate indication of fuel volume. When testing conventional two-line systems, the modulated pressure specification is tested by leaving the intake vacuum hose attached.
Removing the vacuum hose with the engine running delivers an unmodulated fuel pressure reading. Both results should equal specified values. Most systems must also maintain a rest or residual pressure that must be maintained with the key off for a specified length of time.
Residual pressure essentially keeps the fuel injectors primed for the next starting cycle. Although many manufacturers publish a residual pressure specification, some experts insist that the lack of residual fuel pressure appears to cause few noticeable driveability problems.
The most accurate method of testing volume on systems with external fuel pressure regulators is to measure the flow exiting the pressure regulator with the pump activated.
For most applications, the fuel pump should produce at least three pints of fuel in 30 seconds. On single-line systems, the volume can be measured only from a disconnected fuel line.
Because either test requires a fuel return line to be removed, use a scan tool or test connector to activate the fuel pump relay or have a helper ready to shut off the engine.
Whenever performing any fuel system test, have a fire extinguisher at hand and make sure that any potential ignition sources, such as an incandescent light bulb, are removed from the test area. In addition, test results are very application-specific and, therefore, require nameplate experience to interpret the results.
Current ramping is most often used to reveal intermittent electrical failures in the fuel pump relay, inertia switch if so equippedpower supply, motor armature or ground connection. To illustrate, adding several gallons of fuel before testing will eliminate problems caused by an erroneous fuel level gauge.
Before adding fuel, however, always inspect for a badly dented or collapsed fuel tank.
Enter the required amount of volume needed to flow pass per unit of time. Cross-Sectional Area Enter the cross-sectional area perpendicular to the direction of flow of the substance through a pipe, duct or channel at the point of measurement. The formula at the top of the page is Boyle's Law, named after the British chemist Robert Boyle ( - ). It states that the volume of a fixed mass of gas at a constant temperature is inversely proportional to the pressure of the gas. In any pumping system, the role of the pump is to provide sufficient pressure to overcome the operating pressure of the system to move fluid at.
Either type of damage might restrict fuel flow into the fuel pump inlet or from the fuel pressure return line. Next, remember that fuel filters occasionally cause intermittent fuel pump volume failures if the filter media is saturated with dirt and debris.
During a volume test, the regulated fuel should flow smoothly and without large bubbles. An erratic fuel flow might indicate a mechanical problem with the pump assembly or inlet screen.
While some bubbling is normal due to fuel agitation, large bubbles indicate that air is entering the pump inlet. When testing fuel pressure, cycle the fuel pump relay with the key on, engine off several times to see if the fuel pressure remains the same.What would be the volume of vessel 2 in figure if the final pressure read on TC1 and TC2 was Torr rather than Torr?
Charles' Law: Under conditions of fixed volume and amount of . Pump gas molecules to a box and see what happens as you change the volume, add or remove heat, change gravity, and more. Measure the temperature and pressure, and discover how the properties of the gas vary in relation to each other.
Gay Lussac's law, or the pressure law, was discovered by Joseph Louis Gay-Lussac in and states that, for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.
Pressure, Volume, and temperature (PVT) analysis is the determination of the characteristics and behavior of reservoir fluids under various conditions such as pressure, volumes, and temperature.
Pressure as Energy Density. Pressure in a fluid may be considered to be a measure of energy per unit volume or energy density. For a force exerted on a fluid, this can be seen from the definition of pressure: The most obvious application is to the hydrostatic pressure of a fluid, where pressure can be used as energy density alongside kinetic energy density and potential energy density in the.
Boyle's law states that the volume of a gas increases when the pressure decreases at a constant temperature. Code to add this calci to your website Just copy and paste the below code to your webpage where you want to display this calculator.