Which type of water system experience backpressure?

Backpressure occurs in a water system when the pressure upstream (from where the water is supplied) is greater than the pressure downstream (where the water is being discharged). This situation can lead to the contamination of potable water supplies if not properly managed, as it can push potentially contaminated water back into the clean supply.

In a non-potable system under high pressure, backpressure can be significant, especially if there are connections to potable water sources. Non-potable systems, such as irrigation or industrial supply systems, may operate under conditions where pressure fluctuations can cause water supplies to be forced backwards, specifically when pressure conditions change rapidly or when pumps are involved. This makes it essential for backflow prevention measures to be in place to protect the potable water supply from contamination.

On the other hand, potable systems under low pressure typically do not experience backpressure since the pressure is not sufficient to push water back against the flow. A closed system may experience backpressure only under specific conditions, such as temperature changes causing thermal expansion, while a system with no valves would not create backpressure because there are no mechanisms to hold or push the water against the flow direction. Hence, non-potable systems operating under conditions of high pressure provide the most relevant scenario for backpressure.