Various factors play an important role when deciding on a compressed air distribution network. The production pressure is the first parameter that influences consumption and performance. Under no circumstances should the air be produced at a high pressure and then reduced to the consumption pressure in order to compensate for leaks or pressure drops in the network. Each additional bar means a 9 percent increase in output and therefore additional energy costs.

In an average system, the generation pressure is around 7 bar. The network is designed in such a way that this pressure is distributed as evenly and efficiently as possible. An increase from 8 to 10 bar leads to a 15 percent increase in energy costs for compressed air generation. A larger diameter is therefore usually more economical than changing the working pressure.

Maximum flow rate and expansion reserves

The diameter of the main ring must be designed according to the maximum simultaneous extraction at all consumption points. It is also possible to expand production by adding or replacing units with a higher capacity in the compressor room. It is normally difficult to make changes to the main manifold during operation. Once a choice has been made, the system will function for the entire service life of the network. The use of modern modular systems facilitates and accelerates any changes to the secondary network. This reduces the costs for modifications and modernizations.

Pressure losses are caused by the friction of the medium as it flows through the pipe. They are closely related to the speed of the compressed air and the roughness of the pipe. The network diameter should therefore be designed in such a way that the velocity of the fluid in the main lines is as low as possible. The guideline values are 6 m/s or less. A lower velocity results in lower electricity consumption for the production and distribution of compressed air. Modern system planning assumes a maximum pressure drop of 3 percent of the inlet pressure.

Materials and products

A low weight facilitates and speeds up installation, while corrosion- and oxidation-free materials guarantee high-quality compressed air in the long term. The type of connections used to join the pipes is also important. Systems with machined connections made of durable material with high-quality seals offer perfect tightness.

The system layout and diameter of the pipes are based on the position of the tapping points. A closed ring configuration is ideal. Despite a higher initial investment, this offers an even distribution of pressure and a lower pressure drop with the same flow rate in the long term. Modular systems that allow cost-effective modifications, possibly even under pressure, also enable the network to be adapted to an expansion of production.

Correct installation prevents compressed air losses, malfunctions or breakages. Any higher installation costs will pay off in the long term through lower operating, maintenance and repair costs.

Calculation programs for the compressed air sector enable a quick evaluation of different configurations and create reports with the key data. am