How to select the right transfer pump
Learn about transfer pumps and what to consider in order to select the right pump for the job
When moving water from point A to point B, a booster pump is necessary to create a sufficient pressure and lift. This can be the case when using several water tanks at the same time in a domestic building where you need to transfer water from one tank to another, for instance from an underground tank to a roof tank.
Transfer pumps will often be installed outside and must be robust and able to handle the sun, rain, wind and dust.
Transfer pumps are typically used to fill water storage tanks, and as this is a task you most likely just want done as quickly as possible, a fixed speed pump is perfect for the job, while paying for a variable speed motor is an unnecessary expense in a transfer pump.
The pump must also be able to start and stop automatically according to demand in the tank, which is often solved by using a float valve. If the highest tapping point, Hmax is above the start pressure the pump will never start and choosing a pump with an additional external input that can be fitted with a float switch is therefore recommended.
It is also important to take into consideration the pump’s proximity to the domestic building and to neighbouring homes, and to select a pump with a suitable noise-level so that it won’t disturb residents or neighbours. As transfer pumps we recommend using the Grundfos SCALA2, JET pump, or SCALA1. The SCALA2 is more than capable of transferring water from point A to point B and offers a low noise-level and robustness for outdoor installations.
However, it comes with additional advanced features that in most cases will make it overqualified for simply transferring water and an unnecessarily large investment. Both the SCALA2 and the JET pump have adjustable cut-in pressures while the SCALA1 is fitted with an additional external input making it possible to install a float switch that will automatically trigger the pump to fill the tank when the water level hits a selected height.
Both the SCALA1 and 2 are suitable for outdoors installation and have very low noise-levels while the JET pump must be installed in a shed or under a lean-to and is not advisable to use for installations close to a domestic building due to its noticeable noise-level. Lastly, the SCALA1 can be installed as a twin pump to ensure a higher flow.