Locking sizing
Exclude individual routes and fittings from automatic pipe sizing, e.g. for existing lines
Overview
Individual routes and fitting nodes can be locked against the automatic pipe sizing. Locked objects keep their currently assigned pipe type or fitting; only non-locked objects are recalculated. A typical use case is an existing network whose current lines are to remain unchanged during a network extension.
Opening
Pipes tab in the network properties window: with routes or fitting nodes selected, the check box Lock against pipe sizing appears.
Locking individual routes and fittings
- Select the affected routes (or nodes with fittings) in the 3D scene.
- Activate the Lock against pipe sizing check box in the Pipes tab.
The check box is three-state (tristate): with a mixed selection of locked and non-locked objects it is shown partially filled; a click then sets a uniform state for the entire selection. Routes and fitting nodes can be locked separately - the check box appears both on the page for selected pipes and on the page for selected pipe fittings.
Effect
| Operation | Behavior of locked objects |
|---|---|
| Pipe sizing (Size pipes …) | Locked routes are skipped; diameter and pipe type are preserved. After a successful sizing, a notice message lists the skipped pipes and nodes. |
| Fitting recalculation (Recalculate pipe fittings …) | Locked nodes receive no new fittings; a message states the number of nodes left out. |
| Manual pipe assignment | When assigning a pipe type to a locked route, a safety query asks whether the locked line should really be changed. |
| Bill of materials | With the option Group by locking, locked pipe lengths are reported separately - useful when existing lines are not to be newly procured. |
If all routes of a network are locked, the sizing dialog refuses to start with an error message.
Locked objects view
The Locked objects display mode in the Pipes tab shows the lock state color-coded in the model. The legend contains the categories Locked (red) and Not locked (green); via 
Select all locked or non-locked objects can be selected in the scene - for example to set or check the lock state of an entire existing area in a single step.
Notes
- Recommended workflow for existing networks: first manually assign their actual pipe types to the existing lines, then lock these routes and afterwards run the sizing for the network extension.
- The lock only affects the automatic sizing and fitting assignment; the steady-state calculation and simulation use locked routes unchanged with their assigned pipe type.
In practice:
Use the Locked objects display mode to set the lock state: via Select you mark an entire existing area in a single step instead of clicking route by route. Bear in mind that the lock only protects the automatic sizing - in the steady-state calculation and simulation the full water still flows through locked existing lines, so their often narrower diameters can become a bottleneck.