The pipe diameter must allow the required flow to reach the appliances without excessive pressure drop.
What influences the diameter
Key factors include total appliance power, pipe length, number of fittings, and available pressure.
Small diameter
An undersized pipe can cause a pressure drop when multiple appliances operate simultaneously.
Symptoms
A boiler exhibiting low gas pressure, an unstable flame, or an appliance that is not performing at full capacity may be affected by insufficient supply.
Do not choose based on intuition
The cross-section is not chosen because "that is how it is usually done." It must be derived from calculation and the system's design study.
Future additions
If a second appliance is planned for the future, this must be taken into account in the initial design.
