8.4.4. Other calculation options: diameter sizing<br>

### 8.4.4. Other calculation options: diameter sizing

The following, third tab (first tab, when there is no radiant heating in the project) includes all the remaining calculation options: diameter sizing, system adjustment and heat calculations, including radiator sizing. To go to the required set of options select appropriate item in the list on the left side of the screen.

Diameter sizing options – the first set of options displayed – include the following fields:

- Resize diameters – enables diameter sizing during the second and subsequent calculation runs of the project.

- Retain user specified diameters – when diameters are sized, the values specified in the editor are retained.

- Skip to pipe successors – when there is no pipe of the selected type of appropriately large diameter, another type – indicated as the “successor” - is selected from the catalogue (provided that it exists).

- Skip to pipe fitting successors – some pipe fittings and couplings of narrower range of sizes may also have their “successors” with a wider range of sizes indicated in the catalogue.

The main components of the screen are two tables. The upper displays a list of pipe types used in the project. The bottom table displays detailed options of diameter sizing for the type indicated in the upper table. These options include:

- Minimum diameter (inner) that can be used.

- Multiplier for maximum velocity assigned to each diameter in the catalogue.

- Maximum value of friction indicators.

Different values are specified for pipe-runs depending on their location: circuit pipes, horizontal piping in apartments (connected to risers), risers and other parts of the system. Multipliers are used instead of specifying maximum velocity, as in some catalogues different maximum velocities are specified for different diameters. The multipliers used are saved to the project file.

A button ( ) in the selected line of the upper table opens an auxiliary table where maximum velocities (with the multipliers applied) are displayed for the various diameters and where individual diameters may be toggled on/off to be or not to be taken into account when sizing.