Circulator pumps are an essential component of heating and cooling systems, providing the necessary water flow to ensure proper operation. The nominal diameter (DN) of circulator pumps is an important specification to consider when selecting the appropriate pump for your system.

DN refers to the nominal diameter of the pump, which is the internal diameter of the pipe that the pump is designed to fit into. This is important because the diameter of the pipe affects the flow rate and pressure of the water that the pump can circulate. In general, the larger the diameter of the pipe, the greater the flow rate and pressure that the pump can handle.

Common DN sizes for circulator pumps include DN15, DN20, DN25, DN32, DN40, DN50, and DN65. The specific size you choose will depend on the size of your piping system and the flow rate and pressure requirements of your application.

For example, DN15 pumps have a nominal diameter of 15 millimeters and can handle a maximum flow rate of around 1.4 cubic meters per hour. These pumps are typically used in smaller piping systems. On the other hand, DN65 pumps have a nominal diameter of 65 millimeters and can handle a maximum flow rate of around 25 cubic meters per hour. These pumps are typically used in larger, commercial or industrial piping systems.

It is important to note that when connecting different DN sizes, appropriate fittings and seals must be used to ensure a stable and leak-free connection. Choosing the right DN size for your system can help ensure efficient and reliable operation of your circulator pump.

The following are common DN specifications and their characteristics:

• DN15: nominal diameter is 15 mm, pipe inner diameter is approximately 13.5 mm, maximum flow rate is approximately 1.4 m³/h, suitable for small pipe systems.
• DN20: nominal diameter is 20 mm, pipe inner diameter is approximately 18 mm, maximum flow rate is approximately 2.5 m³/h, suitable for general pipe systems.
• DN25: nominal diameter is 25 mm, pipe inner diameter is approximately 22.5 mm, maximum flow rate is approximately 4 m³/h, suitable for general pipe systems.
• DN32: nominal diameter is 32 mm, pipe inner diameter is approximately 28.5 mm, maximum flow rate is approximately 6.3 m³/h, suitable for large pipe systems.
• DN40: nominal diameter is 40 mm, pipe inner diameter is approximately 36.5 mm, maximum flow rate is approximately 10 m³/h, suitable for large pipe systems.
• DN50: nominal diameter is 50 mm, pipe inner diameter is approximately 45.5 mm, maximum flow rate is approximately 16 m³/h, suitable for large pipe systems.
• DN65: nominal diameter is 65 mm, pipe inner diameter is approximately 62.5 mm, maximum flow rate is approximately 25 m³/h, suitable for extra-large pipe systems.

Here is a conversion chart for DN sizes to inches:

DN15 = 1/2 inches

DN20 = 3/4 inches

DN25 = 1 inch

DN32 = 1 1/4 inches

DN40 = 1 1/2 inches

DN50 = 2 inches

DN65 = 2 1/2 inches