Orifice Data Fields (SWMM)
An orifice controls the discharge from a storage unit.
Orifice data can be edited on either the Orifice Grid Window of the Links Grid or the Orifice Property Sheet.
To view and edit all orifice data, use the Property Sheet.
This table describes all the orifice specific data which can be used to define an orifice. For details of results fields, see the Link Results Data Fields topic.
Common Data Fields Fields that are common to the majority of objects can be found in the Common Fields topic.
Orifice Data
Database Table Name: sw_orifice
|
Field Name |
Help Text |
Database Field |
Size |
Precision |
Default |
Error Lower Limit |
Error Upper Limit |
Warning Lower Limit |
Warning Upper Limit |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Link ID |
The unique name used to identify this orifice. This name cannot be used by any other network object on the Links grid. |
id | Text | 254 | 0 | ||||||||||
|
Start node |
The identifier for the upstream node that this orifice (inlet side) is attached to. |
us_node_id |
Text |
254 |
|
0 |
|
|
|
|
|
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|
End node |
The identifier for the downstream node that this orifice (outlet side) is attached to. |
ds_node_id |
Text |
254 |
|
0 |
|
|
|
|
|
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|
Type |
The position of the orifice in relation to the Start node. The following options are available:
|
link_type |
Text |
12 |
|
0 |
|
|
|
|
|
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|
Branch ID |
Numeric field used to identify to which long section the link is associated. Can be set manually or automatically (see Defining Branches topic for more information). |
branch_id |
Long Integer |
|
|
0 |
|
0 |
|
0 |
|
||||
| Shape |
The shape of the orifice. The following options are available:
See example above. |
shape | Text | 16 | 0 | Circular | |||||||||
| Orifice height | The height of a rectangular orifice or the diameter of a circular orifice when the orifice is fully opened. | orifice_height | Double | L | 3 | 1 | 0 | ||||||||
| Orifice width |
Only displayed when the orifice Shape is set to Rect_closed. The width of the rectangular orifice when the orifice is fully opened. |
orifice_width | Double | L | 3 | 1 | 0 | ||||||||
| Invert level | The invert level at which the orifice comes into operation. | invert | Double | L | 3 | ||||||||||
|
Discharge coefficient |
The discharge coefficient for the orifice. |
discharge_coeff |
Double |
|
|
2 |
0.65 |
|
|
|
|
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| Flap gate | A check box which determines whether or not the orifice contain a flap gate. Unchecked (no gate) by default. | flap_gate | Boolean | 0 | False | ||||||||||
| Time to open |
The time required to open a closed, or close an open, Flap gate orifice. Note that control rules can be used to adjust the position of the flap gate. |
time_to_open | Hours | 3 | 0 |
