Pipe2010: Surge node elements include open surge tank, closed surge tank, hybrid tank with compressor, hybrid tank with dipping tube, one-way open tank, bladder surge tank, 1, 2, or 3-stage air vacuum, pressure relief valve, surge anticipation valve, and rupture disk. Click here for a list a steady state devices most of which are supported by Surge.
Open Surge Tank - This is a tank connecting to the pipeline which is open to the atmosphere. If the tank becomes full where water spills over the maximum (Mx) level should be input and the tank is modeled as a spilling tank. See previous note (Closed Surge Tank) if tank is not a vertical cylinder.
Closed Surge Tank - A closed surge tank has a volume of gas, usually air, in the space above the liquid. The gas expands and compresses as flow leaves and enters the tank.
One-Way Open Surge Tanks (Feed Tank) - This open surge tank is equipped with a check valve at the entrance which prevents flow from entering the tank. This is useful for controlling down surges at a point where the static head is large and a normal open surge tank would not be practical
Bladder Surge Tank - This is a closed surge tank with a gas-filled bladder. This tank will activate at the set pressure for the bladder and will act as a closed surge tank for pressures above the set pressure. For pressures below the set pressure the tank has no effect.
Single Stage Air Vacuum Valve - This device takes air in when the pipeline pressure drops below atmospheric and releases air when the pipeline pressure exceeds atmospheric. The single stage air valve has the same size orifice for inflow and outflow (usually the same orifice). Also an initial volume of air can be specified to model startup with air at the air valve location.
Two-Stage Air Vacuum Valve - A two-stage air valve has a different size orifice for inflow and outflow. The outflow orifice is smaller to reduce the rate of air expulsion and the "air slam" which occurs when all the air is expelled and the liquid columns rejoin. See Single-Stage Air Vacuum Valves for additional details.
Three-Stage Air Vacuum Valve - A three-stage air valve has a second outflow orifice (smaller) to release the air more slowly and reduces "air slam". The transition from the primary outflow orifice (diameter D1) to the second orifice (D2) usually occurs at a specified pressure (psi or kpa) but can be modeled to switch on flow (cfs or cms) or volume (ft^3 or m^3).
Pressure Relief Valve - A pressure relief valve is one which opens at a designated pressure (psi or kpa) or head (ft or m) and closes at a second (lower) pressure or head. The opening and closing times are specified.
Surge Anticipation Valve - A surge anticipation valve is a device normally located at a pump discharge which opens on a downsurge at a specified pressure (or head) to provide protection for a subsequent upsurge. Once activated this device works on a timed cycle. The valve opens fully (Open Tm) and stays fully open for a designated period (Open Tm) and then closes (Cls Tm). A sensing node can be designated if the opening is to be activated by the pressure at a different location.
Rupture Disk - A rupture disk is a device which opens quickly (ruptures) at the specified pressure (or head).
Zero Velocity Valve
Junction - A connection of one (dead end junction) or more pipe links.
Reservoir - A connection of one or more pipe links to a constant level reservoir. During a simulation, the reservoir level remains constant unless data is provided to change its value.
Tank - A connection of one or more pipe links to a variable level storage node. For EPS (extended period simulations) level changes are calculated.
Variable Pressure Supply - A connection of one or more pipe links to a supply where the supply pressure depends on the supply flow and is determined by using pressure-flow data (either static pressure, residual pressure and flow, or multiple pressure-flow data points).
Sprinkler (Pressure Dependent Outflow) - A connection of one or more pipe links to a point where flow is discharged into the atmosphere based on the pressure in the distribution system. The characteristics of a connecting pipe may be defined (length, diameter, elevation change). This device can model a leak or a pressure sensitive demand.
Pumps - A connection of one or more pipe links to a pump. The pumps characteristics may be defined by constant power, a rated condition, head-flow data, or a pump file.
Loss Element - An element identical to a pump except instead of a head gain, a head loss occurs.
Regulator - A connection of one or more pipes is required to each side of the device that maintains downstream pressure (pressure regulating valve), upstream pressure (pressure sustaining valve) or flow (flow control valve).
Back Flow Preventer - A special loss element for which head flow data is provided based on manufacturer, model, and size.
Active Valve - A valve for which the open ratio may be specified and for which the head loss based on the valve opening is included in the network analysis.
Blowoff/Nozzle - This element models a section of piping which discharges through an orifice to the atmosphere. It models a blowoff or hydrant.
Turbine - This element removes energy (head) from the flow and the head-flow characteristics are described by a file of data. This element is nearly identical to a pump described by a pump file except there is a head loss instead of head gain.
Wicket Gate - This element simulates a gate valve which controls the flow through the turbine. The percent opening of the gate is required data and can be varied.
LPS Tank - Used for modeling small liquid holding tanks with attached submersible pumps.
Hydropneumatic or Pressurized Tank - Uses air pressure to supply pressure to move water out of tanks. When low, water is added to build up pressure. For this element an external pump is specified which operates to fill the tank when the pressure falls below a certain level and turn off when above a certain pressure level.
Vacuum Breaker - This device models the effect of a Vacuum Breaker which admits air to the pipeline when the pressure is sub atmospheric. Without this device hydraulic calculations will be incorrect if sub atmospheric pressures develop. Note: the directional arrow should be in the normal direction of flow.
Check Valve - Allow flow only in the specified direction. If conditions exist for flow reversal, the valve closes and the line carries no flow
Hydrants - Pipe2010 models fire hydrants and provides the capability of plotting field hydrant flow data, calculating fire flows and maintaining records using the model.
On/Off Valve - A cut-off or isolation valve.
Meters - A metered connection node can be defined at any junction or inserted into a pipe. Each Metered Connection in a model can have several associated meters, each with it's own demand, demand type, name, and user data (e.g. address).
