Pipe Database

Overview

The pipe database contains all pipe cross-sections available for network routes and pipe sizing. A pipe is defined through its geometric and thermal properties: outer diameter, wall thickness, roughness, wall material, as well as insulation or a fixed U-value. The built-in database comes with several hundred entries of common pipe series, including PE, insulated PE, steel pre-insulated bonded pipe and copper pre-insulated bonded pipe.

Opening

• Menu Databases > Pipes …
• in selection mode wherever a pipe is assigned, e.g. in the route properties or in the pipe selection for pipe sizing

General Information

Field	Meaning
Name	Automatically generated from the dimensions (see naming conventions) and not directly editable.
Material name	Freely selectable group or category name, e.g. pipe series or material (multilingual possible).
Manufacturer, Product	Optional manufacturer details.
Material type / standard	Determines the naming convention: Plastic pipe, EN standard or Metric designation (da x s).
Arrangement of the pipes	Single pipe (supply and return separate) or twin pipe (supply and return in a common insulation).
Nominal pressure (PN)	Standardized nominal pressure in bar, default: 16 bar (display field).
SDR value	Calculated automatically: $SDR = d_a / s$ (outer diameter to wall thickness), a characteristic value for the mechanical strength.

Naming Conventions

Material type / standard	Naming scheme	Example
Plastic pipe	Outer diameter x wall thickness in mm (“da x s”)	25 x 2.3
EN standard	Nominal size, determined from the outer diameter via the standardized steel-pipe series	DN 50
Metric designation (da x s)	like plastic pipe, for non-plastic pipes	60.3 x 2.9

Pipe Properties

Parameter	Unit	Meaning
Outer diameter	mm	Outer diameter of the media pipe, without insulation
Pipe wall thickness	mm	Wall thickness; the inner diameter results as $d_i = d_a - 2s$
Pipe roughness	mm	Hydraulic roughness of the inner pipe wall (pressure-loss calculation)
Thermal conductivity of pipe wall	W/mK	Thermal conductivity of the wall material
Heat capacity of pipe wall	J/kgK	Specific heat capacity of the wall material (thermal inertia in the dynamic simulation)
Density of pipe wall	kg/m³	Density of the wall material

Insulation and U-Value

For the thermal losses there are two input modes, switchable via the options Insulation thickness given and U-value given:

Mode 1: Insulation thickness given

Parameter	Unit	Remark
Thickness of the insulation	mm	0 permissible (uninsulated pipe)
Thermal conductivity of the insulation	W/mK
Thickness of the outer protective layer	mm	Outer jacket, e.g. PE jacket for pre-insulated bonded pipe; 0 permissible
Total outer diameter	mm	calculated: $d_a + 2\,s_D + 2\,s_M$
U-value	W/mK	calculated, see formula below

The length-related U-value is calculated from the logarithmic conductive resistances of the layers:

$$U = \frac{\pi}{R}, \qquad R = \frac{1}{2\lambda_W}\ln\frac{d_a}{d_i} + \frac{1}{2\lambda_D}\ln\frac{d_a+2 s_D}{d_a} + \frac{1}{2\lambda_W}\ln\frac{d_a+2 s_D+2 s_M}{d_a+2 s_D}$$

with $d_a$/$d_i$ outer/inner diameter, $s_D$ insulation thickness, $s_M$ thickness of the outer jacket, $\lambda_W$ thermal conductivity of the pipe wall and $\lambda_D$ of the insulation. The outer jacket is assumed to have the thermal conductivity of the pipe wall. Without insulation ($s_D = 0$), only the wall resistance remains.

Mode 2: U-value given

Parameter	Unit	Remark
U-value	W/mK	fixed length-related U-value, e.g. from the manufacturer’s data sheet
Total outer diameter of the insulated pipe	mm	Outer diameter including insulation and jacket
Distance of the pipes	mm	only for the twin pipe: axial distance between the supply and return pipe in the common insulation

Single and Twin Pipe

For the single pipe, supply and return are separate pipes; each pipe is assigned the defined U-value. For the twin pipe, both lines lie in a common insulation. Twin pipes must be defined in the mode U-value given; the specified U-value applies to both pipes together and is split in half between supply and return for the simulation.

Predefined Pipe Series

The built-in database contains complete pipe series in the categories:

Category	Typical application
PE	uninsulated plastic pipes, e.g. cold district heating
Insulated PE	insulated plastic pipes
Steel pre-insulated	pre-insulated bonded pipes with a steel media pipe
Copper pre-insulated	pre-insulated bonded pipes with a copper media pipe

Built-in pipes are read-only; using the copy function of the dialog, they can be used as a template for your own variants.

Notes

• A pipe is only valid if the inner diameter is positive ($d_a > 2s$); invalid entries are marked in the list.
• In the pipe selection for sizing, you use checkboxes to determine which pipes the algorithm may use - see Performing pipe sizing.

Related Topics

• Database concept
• Pipe sizing: method
• Fittings