Bypass section selection when installing a circulation pump

Hello!

I wanted to install a circulation pump through a bypass on a single pipe system. The main pipe is 32 mm. Should the bypass diameter be reduced or not? Thanks in advance!

Nurzhan

Expert Answer

Hello, Nurzhan.

When using a circulation pump, experts recommend choosing a bypass section 1-2 sizes smaller than the diameter of the main pipe. In your case, to make a bypass, you must use a steel pipe with a cross section of 1 inch (25 mm). As shutoff valves, ball valves are best suited - they have the lowest hydraulic resistance. In addition, be sure to install a coolant pre-filter in front of the circulation pump. In the impellers of modern pumps, plastic blades are most often used, so sand, rust and other small abrasive substances contribute to their increased wear. As practice shows, the presence of a filter element significantly increases the service life of the circulation pump even in individual heating systems, not to mention the centralized supply of hot water.