Friction loss calculator

The friction loss calculator allows you to determine the loss for a 100-metre straight pipe. Using the table on the back, you can calculate the loss for various fittings. You’ll find the fictitious length for different fittings along with their respective diametres.

Example

Flow: 20 m³/h through a PVC 75 pipe (pipe size 65 mm)
Velocity: 1.65 m/s
Friction loss: 4.2 mwc per 100 metres of pipe
Total pipe length: 80 metres. Additionally, there are 3 elbows, 1 T (straight through), and a non-return valve spring present.
Fictitious length: 80 + (3 x 2.6) + 1.7 + 33.2 = 122.7 metres

The friction loss is then 4.2 / 100 x 122.7 = 5.15 mwc.