Valve Dimensioning Tool

Valve Dimensioning Tool: How to find the optimal valve dimension

Valve and pipe dimensions are still automatically selected to be the same by many installers, although a smaller valve dimension is often more advantageous for a precise flow. This calculation tool helps you to get an indication for the best valve size for your water (or similar) installation.

Select the required valve type and pipe size and enter your process parameters. Then you can choose between different valve sizes. If the working range of the selected valve is optimal, you will see it, marked by two red lines, in the green area of the diagram. If not, please correct accordingly:

  • If the opening angle is in the front orange section, select a smaller valve size.
  • If the opening angle is in the back orange section, select a bigger valve size.
  • If there is no red line in the graph, please check if the flow rate is within the range of the selected valve.

If you are not sure about the exact value of outlet pressure (P2), we suggest to start with a ΔP of 15% up to 20% of the inlet pressure (P1). (ΔP=P1-P2)

The tool uses the following formula to calculate the flow value: Q =Kv100*√∆P. 
This equation is only valid for fluids with a density of 1 kg/dm³.

In case of any other medias we recommend to contact GFPS Global Sales Support or your local sales. GF will be happy to share with you its extensive practical experience, gained over decades in the field of polymer piping system applications in industry and chemical engineering.


Georg Fischer Piping Systems Ltd

Ebnatstrasse 111

8201 Schaffhausen


GF logo on the headquarters building