Supported Elements and Devices for GoFlow

GoFlow supports all of the KYPipe (steady-state) devices. Here is a summary of the key GoFlow devices. GoFlow node elements include junctions, reservoirs, pumps, sprinklers, rack sprinklers, loss elements, loss elements defined by manufacturer data from a library, variable pressure supplies, check valves, active valves, intermediate nodes, and user-defined devices.

 Device Inputs and Graphical Description

Device Text Description

Active Valve – A valve for which the open ratio (stem position) may be specified and varied. The program incorporates the Cv (valve coefficient) ratio as a function of stem position for a number of standard valves (ball, butterfly, globe, gate, etc.). Users can provide data for other valve types.

Blowoff/Nozzle – This element models a hydrant and section of piping which discharges through an orifice to the atmosphere. It can be used to model the effect of opening a dead-end blowoff.

*Check Valve – Inserted into a pipe, this device allows flow only in the specified direction. If conditions exist for flow reversal, the valve closes and the line carries no flow. Active Valves and Pumps may also incorporate Check Valves. Note: the directional arrow should be in the normal direction of flow.

Check Valve Element – This node is independent of other nodes that may incorporate internal Check Valves, i.e., Active Valves and Pumps. Its closure characteristics may be based on standard valves (stem position vs. area ratio for Ball, Butterfly, Globe etc). Accelerated closure, differential pressure and flow may also be applied. See Check Valve.

*Device 1 and 2 – See User-Defined Nodes.

*Intermediate Node – Inserted into an existing pipe, intermediate nodes allow for changes in pipe direction and/or elevation.

Internal Nodes – Because these are internal to a pipe, they do not stop a pipe and start a new pipe.  However, because no new pipe is created by the addition of the internal node and results are not computed for them, they do not add to model overhead.  Check valves, hydrants, intermediate nodes, metered connections, on/off valves and user-defined devices are internal nodes.

Junction – A connection of one (dead-end junction) or more pipe links. A junction may be placed at a high or low point in a pipeline to calculate results for these locations. Junctions may incorporate static demands or demand patterns.

Library Back Flow Preventer (BFP) – A special loss element for which a head-flow data Library is provided based on manufacturer, model, and size.

Loss Element – An element identical to a pump except instead of a head gain, a head loss occurs across this device.

*Metered Connection – 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 its own demand, demand type, name, and user data (e.g., address).

*On/Off Valve – A cut-off or isolation valve which can be closed to prevent flow in the pipeline.

Pump(s) – A connection of one or more pipe links to a Pump. The Pump’s characteristics may be defined by constant power, a rated condition, head-flow data, or a Pump file which includes data for all zones of operation. Multiple Pumps (parallel or series) may also be modeled using the Pump element.

Regulator – A connection of one or more pipes is required on each side of this device, which maintains downstream pressure (Pressure Regulating Valve), upstream pressure (Pressure Sustaining Valve) or flow (Flow Control Valve).

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 for a particular simulation or at a specified time.

Sprinkler (Pressure Dependent Outflow) – A connection of one or more pipe links to a point where flow is discharged through an opening (orifice) into the atmosphere (or a region of known pressure) based on the pressure in the distribution system. The characteristics of a connecting pipe may be defined (length, diameter, elevation change).

Tank – A connection of one or more pipe links to a variable-level storage node. For Extended Period Simulations (EPS), level changes are calculated. This device can be cylindrical or have any shape defined by the user.

*User-Defined Nodes – Referred to as Device 1 and Device 2, these are passive, internal nodes which may be used to represent other devices. They may also serve as location markers, or may be used to reference data such as addresses, notes, dates, etc.

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 from either 1) static pressure, residual pressure and flow, or 2) multiple pressure-flow data points.

 * These are internal nodes which do not add to model overhead.