An orifice is a command, usually located at the outlet, to reduce, measure, or restrict a flow.

Parameter Name Description Default Value
NHYD Hydrograph number.
NAME Name of the component.
From Node The name of the from node.
To Node The name of the destinated node.
COMMENT 1, 2, and 3 Comment for the command.
Tag Optional category or classification.
System Type Specifies the junction’s system type, whether it belongs in the overland, storm, or sanitary system. Blank
Height [m] Height of orifice opening when fully open (ft or m). Corresponds to the diameter of a circular orifice or the height of a rectangular orifice. 1
Width [m] Width of rectangular orifice when fully opened (ft or m). 1
Inlet Offset [m] Depth or elevation of the bottom of the orifice above the invert of the inlet node (feet or meters). 0
Type Type of orifice (Side/Bottom).
Shape Orifice shape.
Discharge Coeff. Discharge coefficient (unitless). A typical value is 0.65. 0.65
Flap Gate YES if the flap gate exists that prevents flow back through the orifice, or NO if no flap gate exists.
Time to open/close The time to open a closed (or close an open) gated orifice in decimal hours. Use 0 or leave blank if timed openings/closings do not apply.