A pressure-reducing valve, often abbreviated to PRV, is installed on the incoming mains water supply to a property to reduce pressure to a level that is safe for fittings, appliances and the building. UK PRVs are manufactured to BS EN 1567 and must be installed in accordance with the Water Supply Fittings Regulations 1999. In parts of Greater London, mains pressures can routinely exceed 5 bar, which can damage modern combination boilers, ceramic disc taps, washing machines and water filters. A PRV usually limits pressure to between 2.5 and 3.5 bar to suit the installed appliances. Installation should include an isolation valve and a pressure gauge for commissioning. Regular inspection ensures that the diaphragm and seat remain in good condition over many years.
Pressure-reducing valve (PRV)
Valve that lowers incoming mains water pressure to a safe level for the property.
