What backflow is, how backsiphonage and backpressure cause it, where the path comes from, and why the device must suit the form that can occur.
Backflow is water flowing back towards the supply instead of out to the user. It matters because water that has been in contact with a contaminant can carry it into pipework that other people drink from.
Read the full Water Regulations note with Premium
You’re reading the free preview. PlumbRevise Premium unlocks the complete write-up, the worked detail for every Water Regulations note — plus timed tests on every module.
Plenty of modules are free to read in full.