GIS-IDs: List of associated IDs on the GIS/data-source side.
Hyperlinks: Associate one or more web link, photo, word processing document, or other file with this element.
Volume of Gas (Initial): The initial volume of gas in the pressure vessel at the start of the simulation. During the transient event, this gas volume expands or compresses, depending on the transient pressures in the system. Not used in steady state or EPS analyses.
Diameter (Tank Inlet Orifice): The size of the opening between the gas vessel and the main pipe line. It is typically smaller than the main pipe size.
Ratio of Losses: For same flow magnitude, ratio of inflow head loss to outflow loss. Default value is 2.5.
Gas Law Exponent: Refers to the exponent to be used in the gas law equation. The usual range of this exponent is 1.0 to 1.4.
Pressure (Gas-Preset): If there is a bladder, this is the pressure of the gas prior to exposing the tank to pipeline pressure; otherwise, this should be omitted as it is ignored.
Liquid Elevation (Mean): The mean elevation of the liquid at the gas-liquid interface. (Liquid level referenced from a datum of 0).
Elevation Type: Choices: Fixed, Mean Elevation, Variable Elevation
Variable Elevation Curve: Defines the gas vessel chamber geometry as a function of liquid elevation versus equivalent diameter.
Minor Loss Coefficient (Outflow): Dimensionless quantity, typical value = 2.5. This property is used only for transient analysis, to restrict the flow out of the hydropneumatic tank.
Elevation (Base): Elevation of the storage tank base used as a reference when entering water surface elevations in the tank in terms of levels.
Treat as Junction? - Selects whether or not the hydropneumatic tank is treated as a junction in steady state and EPS simulations. Note that if you wish to use the steady state/EPS results as input for a HAMMER transient analysis and you set this field to True, you will need to manually enter the Volume of Gas (Initial) for the tank for HAMMER
Volume of Gas (Initial) - The initial volume of gas in the pressure vessel at the start of the simulation. During the transient event, the gas volume expands or compresses, depending on the transient pressures in the system. This value is not used in steady state or EPS analyses.
Operating Range Type: Choices: Elevation, Level
Tank Calculation Model: Choices: Constant Area Approximation, Gas Law Model
Volume (Effective): The effective volume of the constrant area approximation hydropneumatic tank.
HGL On: The lowest operational hydraulic grade desired for the hydropneumatic tank. You should define a simple or logical control that uses this hydraulic grade as the minimum operational value. For example, define a control to turn on a pump.
HGL Off: The highest operational hydraulic grade desired for the hydropneumatic tank. You should define a simple or logical control that uses this hydraulic grade as the maximum operational value. For example, define a control to turn off a pump.
Atmospheric Pressure Head: This field represents atmospheric pressure and is used in the gas law model computation of the hydropneumatic tank.
HGL (Initial): Starting water surface elevation/level in the tank. Used in steady state and EPS analyses.
Level (Initial): Starting water surface elevation/level in the tank. Used in steady state and EPS analyses.
Liquid Volume (Initial): Starting liquid volume in the tank. For constant area approximation tanks this volume includes the inactive volume of the tank that lies below the effective volume. Only used in steady state and EPS analyses.
Air Flow Curve (Air Inflow Orifice): Curve that defines orifice behavior for the injection of air into the pipeline.
Air Flow Curve (Air Outflow Orifice): Curve that defines discharge of air when the volume is greater than or equal to the transition volume (TV).
Air Flow Calculation Method: Choices: Orifice Diameter, Air Flow Curve
Installation Year: Specify the install year of the element. It does not affect the calculations.
Elevation (Initial, Transient): Enter a value only if a check valve is installed (i.e., case of a one-way surge tank), or there is an initial inflow/outflow head loss. By default, the intial water surface level is taken equal to the head in the adjacent pipe.
Report Period (Transient): Number of time steps between successive printouts of operation. By default, this printout is suppressed.
Demand Collection: A collection of baseline demands and associated temporal patterns.
Unit Demand Collection: A collection of unit demands, associated unit counts, and temporal patterns.
Elevation: Elevation at centroid of junctions, valves, and pumps; the ground elevation at tanks; the hydraulic grade at reservoirs.
Trace (Initial): Specify the initial trace amount at the current location.
Zone: Specify the zone for the element.
Concentration (Initial): Specify the initial concentration for the global concentration at the selected element.
Is Constituent Source?: If true then the selected node can inject a set concentration of the global constituent into the system.
Pattern (Constituent): Specify the pattern which dictates how the injected constituent concentration varies over time.
Concentration (Base): This data field allows you to specify the corresponding constituent concentration at this node over time.
Mass Rate (Base): This data field allows you to specify the corresponding constituent mass rate at this node over time.
Age (Initial): Specify the initial age of the fluid at the selected element.
Gas Volume (Calculated): The calculated volume of gas in the hydropneumatic tank.
Pressure (Calculated): The calculated pressure in the hydropenumatic tank.
Liquid Volume (Calculated): The calculated liquid volume in the hydropneumatic tank.
Percent Full: The ratio of the fluid volume in the tank to the calculated full volume of the tank.
Flow (Out net): Net flow out of the element.
Flow (In net): Net flow into the element.
Demand Adjusted Population: Population of area supplied by current node. This value is derived from the unit demand loads applied to the collection and their equivalent populations.
Hydraulic Grade: Calculated hydraulic grade at node.
Age (Calculated): Age at selected element for current time step.
Trace (Calculated): Trace at selected element for current time step.
Concentration (Calculated): Concentration at selected element for current time step.
Has Calculation Messages Now?: If true then the current element has associated calculation warning messages for the current time step.
Head (Maximum, Transient): Maximum head at node over the course of the transient simulation.
Head (Minimum, Transient): Minimum head at node over the course of the transient simulation.
Pressure (Maximum, Transient): Maximum pressure at node over the course of the transient simulation.
Pressure (Minimum, Transient): Minimum pressure at node over the course of the transient simulation.
Air Volume (Maximum, Transient): Maximum air volume at node over the course of the transient simulation. Not applicable to Reservoirs and Rating curves.
Vapor Volume (Maximum, Transient): Maximum vapor volume at node over the course of the transient simulation. Not applicable to Reservoirs and Rating curves.
Gas Pressure (Maximum, Transient): Maximum gas pressure at node over the course of the transient simulation.
Gas Pressure (Minimum, Transient): Minimum gas pressure at node over the course of the transient simulation.
Gas Volume (Maximum, Transient): Maximum gas volume at node over the course of the transient simulation.
Gas Volume (Minimum, Transient): Minimum gas volume at node over the course of the transient simulation.
Water Level (Maximum, Transient): Maximum water level in tank over the course of the transient simulation.
Water Level (Minimum, Transient): Minimum water level in tank over the course of the transient simulation.
