For years I’ve had to listen to my pump system manufacturer tell me that their systems work great without pressure tanks. All the while, having to supply pressure tanks on almost every system, in order to make the work correctly. Now I can finally tell you the truth: you need a pressure tank with a booster system! Your alternative is high pressure swings or wasted energy. This company gives you the high pressure swings. Look at these 2 videos.
The fact is, you don’t want a pump to react as fast as the pressure can change, when there’s not a pressure tank. It causes pressure swings like you see in the video. Perhaps worse than the big pressure drops are when the pump overshoots, causing alarms. The only way that I have seen manufacturers avoid the pressure swings without using a tank, is to bypass some water back to suction header. This causes the pump to run almost continuously, and wastes energy.
This is why we always recommend a pressure tank, for best operation and efficiency. But if one isn’t specified, then we will supply without.
And the pressure tank that we recommend, is the one that took us 20 years to find. Here