What factors can cause a back pressure-backflow condition?

Back pressure-backflow is created whenever the downstream pressure exceeds the supply pressure, which is possible in installations such as heating systems, elevated tanks, and pressure-producing systems. An example would be a hot water space-heating boiler operating under 15-20 pounds of pressure coinciding with a reduction of the city water supply below this pressure (or higher in most commercial boilers). As water tends to flow in the direction of least resistance, a back pressure-backflow condition would be created and the contaminated boiler water would flow into the potable water supply.

Show All Answers

1. What is Backflow?
2. What is back-siphonage?
3. What factors can cause back-siphonage?
4. What factors can cause a back pressure-backflow condition?
5. What is a cross connection?
6. What is the most common form of a cross connection?
7. How can you help prevent backflow conditions?