Transient - Surge Protection Device page

This page is used to model a surge protection device.

This page is available on the Node properties sheet when the Add Control button has been pressed (for a checked out network with an associated base control).

Item Description

Enable Surge

Check this option to allow a surge protection device to be modelled.

Surge Protection

Dropdown list of surge protection devices. Enabled when the Enable Surge option is checked.

BLAD_SRG_T Bladder Surge Tank Closed surge tank containing a gas filled bladder. The bladder is pre-charged to a pre-determined pressure to maintain desired air volume under normal operating conditions.
CLOS_SRG_T Closed Surge Tank Surge vessel containing a specified initial gas volume. The gas expands and compresses as flow exits and enters the tank.
ESRG_ANT_V Electronic Surge Anticipation Valve

Control is via a solenoid. In reality valve opens when solenoid is de-energised (either by power failure or through pressure switch on low pressure).

In this version of InfoWorks WS a simplified version of the electronic surge anticipation valve may be modelled where valve opening occurs when:

  • Initial Delay Time from run start time is reached. The valve follows an opening and closing cycle determined from Opening Time, Fully Open Time and Closing Time values.
  • Pressure exceeds High Opening Pressure at Sensing Node ID location. The valve follows an opening and closing cycle determined from High Opening Time and High Closing Time values.

If the valve exits to a pressurised region, an External pressure should be specified.
HSRG_ANT_V Hydraulic Surge Anticipation Valve

Valve is activated as a normal pressure relief valve when pressure exceeds a preset maximum or on a downsurge of pressure in anticipation of an upsurge to follow.

Valve opening will occur when:

  • High Opening Pressure at a specified location (Sensing Node ID) is exceeded. The valve follows an opening and closing cycle determined from High Opening Time and High Closing Time values.
  • Pressure drops below Low Opening Pressure at Sensing Node ID location. The valve follows an opening and closing cycle determined from Low Opening Time and Low Closing Time values.

If the valve exits to a pressurised region, an External pressure should be specified.
ONEW_SRG_T One Way Surge Tank An open surge tank that allows flow from the tank into the pipe at periods of low pressure. A non-return valve prevents flow from entering the tank from the system.
OPEN_SRG_T Open Surge Tank Tank which is open to atmosphere. A Max tank depth is specified, above which spilling occurs.
PRESS_RV Pressure Relief Valve Valve opening is activated when Opening pressure at a specified location (Sensing Node ID) is exceeded. Valve closure is initiated when pressure at the sensing node reaches the Closing pressure. If the valve exits to a pressurised region, an External pressure should be specified.
RUPT_DISK Rupture Disk Device containing a non-reusable membrane designed to fail at a given pressure. Modelled by specifying an Opening Pressure
SIDE_DIS_O Side Discharge Orifice Represents an orifice in the pipeline where flow enters or exits based on standard orifice behaviour
SRG_ANT_V Surge Anticipation Valve Valve opening is activated on a downsurge of pressure in anticipation of an upsurge to follow. Valve opening will occur when Opening pressure at a specified location (Sensing Node ID) is met. The valve follows an opening and closing cycle determined from Opening Time, Fully Open Time and Closing Time values. If the valve exits to a pressurised region, an External pressure should be specified.
STGAVV_12 1 and 2 Stage Air Vacuum Valve

Single stage and 2 stage air/vacuum valves allow air into the system when pressure in the pipeline drops below atmospheric and release air when pressure in the pipeline is greater than atmospheric. An Initial Gas Volume may be specified.

A single stage valve has a single orifice for inflow and outflow. To model a single stage valve, specify the same value for Inflow Diameter and Outflow Diameter.

A 2 stage valve has a different size orifice for inflow and outflow. A smaller outflow orifice is used to reduce the rate of release of pressurised air in order to reduce 'air slam'. To model a two stage valve, specify the diameter of the orifice that allows air to enter the system as the Inflow Diameter, and the diameter of the orifice that allows air to exit the system as the Outflow Diameter.
STGAVV_3 3 Stage Air Vacuum Valve

A 3 stage air/vacuum valve has one inflow orifice that allows air to enter the system when pressure in the pipeline drops below atmospheric and two outflow orifices to release air when pressure in the pipeline is greater than atmospheric. An Initial Gas Volume may be specified. The first outflow orifice is a larger diameter allowing most of the air to be expelled quickly. The second smaller outflow orifice is used to reduce the rate of release of pressurised air in order to reduce 'air slam'.

To model a three stage valve, specify the orifice diameters in the Inflow Diameter, Outflow Diameter and Outflow Diameter 2 fields.

The switch from primary to secondary orifice can be controlled by flow, pressure or volume. Select the control parameter from the Switching Type dropdown and enter the switching value in the appropriate Switching field.

Property Sheets

Nodes

Basic Node Data Fields

Hydrant Node Data Fields

Control Data