# Result Table - Gas Regulator

The available results that are listed in the table vary depending upon the fluid phase state and upon the visible properties that you have selected. Figure 1 shows all of the available results for a gas phase state. Figure 2 shows the normal or default rows. You can choose the rows you wish to display in the results table via the Set Visible Results Dialog. Figure 1: Available results for a gas regulator. Only descriptions for the default results are shown in this section. If you wish to see the definition for other values click here. -- ID -- (aka User Number): All flowsheet elements have a unique number that is assigned by FluidFlow. It is not possible for the user to change this number because it is used as a unique identifier by the scripting module. Node numbering starts from 1, incrementing upwards, and pipe numbering starts from -1, decrementing downwards. Calculated C v: This is the calculated flow coefficient for the regulator. Composition Mass %: This is the fluid mass composition that remains constant throughout the element. FluidFlow determines the composition because an individual component mass balance is carried out at each node. Flow: This is the flow through the gas regulator that FluidFlow has calculated will be flowing. This flow will adjust in order achieve the pressure setting you have previously made via the input editor unless the regulator is unable to control at the pressure that you have specified. In this case the volumetric flow refers to the actual volume flow at the inlet to the regulator. Flow at NTP: This is the gas volumetric flow referenced to normal conditions (0°C and 101325 Pa). NTP flow is the same as the gas flows across the regulator. Flow at STP: This is the gas volumetric flow referenced to standard conditions (15°C and 101325 Pa). STP flow is the same as the gas flows across the regulator. Heat Transferred: If the Heat Loss Model is not equal to "Ignore Heat Loss/Gain", then an additional row will appear in the results table showing the amount of heat that has been transferred. In Density: The fluid density at the regulator inlet conditions. Density depends on temperature and pressure of the fluid. In Fluid Phase: The fluid phase state at the regulator inlet. In Stagnation Pressure: The stagnation pressure at the regulator inlet. This is the sum of kinetic and pressure energies (static pressure + velocity pressure). Stagnation pressure is the pressure a flowing fluid would rise to if brought isentropically to rest, converting its kinetic energy to enthalpy. In Stag. Temperature: This is the stagnation temperature at the regulator inlet. The stagnation temperature is the temperature that the fluid would reach if it were brought to rest isentropically, converting its kinetic energy to enthalpy. In Static Pressure: This is the pressure that acts equally in all directions at the point in the fluid and is present irrespective if the fluid is flowing or if the fluid is at rest. The pressure inside any regulator is not the static pressure, unless there is no flow. In Static Temperature: The static temperature at the regulator inlet. Static temperature is related to stagnation temperature (ignoring work, heat exchange, and potential energy) by the equation T 1 = T 1 0 - 0.5 v 1 2 / C p In Velocity: The velocity at the regulator inlet. For gases, velocity and actual volumetric flow increases as the fluid moves across the regulator. This can also occur with two phase flow where flashing exists, or for an incompressible where the temperature rises. Velocity can also decrease as a fluid flows across an element, for example cooling of a liquid. Joule–Thomson Coefficient: The Joule–Thomson effect describes the increase or decrease in the temperature of a gas when allowed to expand. The change in temperature (T) with a decrease of pressure (P) at constant enthalpy (H) is referred to as the Joule–Thomson coefficient (μJT). FluidFlow uses the Peng Robinson EOS to evaluate the Joule–Thomson coefficient which is expressed as: μ JT = (∂T/∂P)H The value of μJT is typically expressed in °C/bar and is dependent on the physical properties of the gas, as well as the temperature and pressure of the gas before expansion. Out Density: The fluid density at the regulator outlet conditions. Density depends on temperature and pressure of the fluid. Out Fluid Phase: The phase state at the regulator outlet. Out Stagnation Pressure: The stagnation pressure at the regulator outlet. This is the sum of kinetic and pressure energies (static pressure + velocity pressure). Stagnation pressure is the pressure a flowing fluid would rise to if brought isentropically to rest, converting its kinetic energy to enthalpy. Stagnation pressure is a measure of the usefulness of the gas's energy. Out Stag. Temperature: This is the stagnation temperature at the regulator outlet. The stagnation temperature is the temperature that the fluid would reach if it were brought to rest isentropically, converting its kinetic energy to enthalpy. Out Static Pressure: This is the pressure that acts equally in all directions at the point in the fluid and is present irrespective if the fluid is flowing or if the fluid is at rest. The pressure inside a regulator is not the static pressure, unless there is no flow. Out Static Temperature: The static temperature at the element outlet. Static temperature is related to stagnation temperature (ignoring work, heat exchange, and potential energy) by the equation T 2 = T 2 0 - 0.5 v 2 2 / C p Out Velocity: The velocity at the regulator outlet. For gases, velocity increases as the fluid flows across the regulator. This can also occur with two phase flow where flashing exists, or for an incompressible fluid where the temperature rises. Velocity can also decrease, for example cooling of a liquid. Total Pressure Loss: This is the calculated total pressure loss across the regulator. Total pressure loss is not always the same as frictional loss, for example, when a temperature or velocity change occurs. In FluidFlow total pressure loss is defined (from the Energy Equation) as Δ P = (z 1 ρ 1 g + p 1 + 0.5 ρ 1 v 1 2) - (z 2 ρ 2 g + p 2 + 0.5 ρ 2 v 2 2)