Find the correct DN pipe size for your compressed air distribution run and verify pressure drop stays within limits.
Enter flow, length and pressure to size the pipe.
Uses Rohrback approximation formula. Sizes: DN15, 20, 25, 32, 40, 50, 65, 80, 100. Target ≤ 0.1 bar drop for main rings.
The industry standard is a maximum 0.1 bar (10 kPa) pressure drop across the main distribution ring at full flow. For branch lines, an additional 0.1 bar is typically allowed. Total system pressure drop from compressor to point of use should not exceed 0.3 bar to avoid efficiency losses.
A ring main (loop) feeds each outlet from two directions simultaneously, halving the effective pipe length and reducing pressure drop. It also provides redundancy — if one section is isolated for maintenance, supply is maintained from the other direction. Ring mains are recommended for most workshop and factory installations.
1 CFM (cubic foot per minute) = 28.32 litres per minute. To convert L/min to CFM: divide by 28.32. For example, 300 L/min ÷ 28.32 = 10.6 CFM. The calculator shows both units in its results.