Pressure Relief Valves are also known as PRV’s, Safety Valves, and Expansion Relief Valves. The function of this type of Valve is to relieve the system of over pressure in a safe manner. Most consumers will take for granted the operation of a Pressure Relief Valve (PRV) and believe “out of sight, out of mind”, this is potentially lethal if you take into consideration the functionality of a Pressure Relief Valve and also the consequences if they are not correctly maintained. Manufacturers of Pressurised Water Heaters will advise that all safety control devices including Pressure Relief Valves should be annually maintained and serviced. Pressure Relief Valves are set to a specific pressure to ensure maximum safety for you and your System. Whilst you can find Pressure Relief Valves with adjustable pressure settings it is recommended that on a pressurised system that the valve is to be set to the manufacturers recommended pressure and should not differ from this unless the manufacturer recommends to do so. As they are a vital part of the safety mechanism on a pressurised water heater Pressure Relief Valves should not be disconnected or removed unless you are replacing immediately. Pressure Relief Valves date back to as early as 1679 on the Steam Digester where a weight was used to hold down the pressure of steam, this however was not as reliable as new Pressure Relief Valves which use a spring mechanism to achieve the same desired function. Whilst a simple weight was effective in holding back pressure this could easily be tampered with and would no longer pass the regulations for current Pressure Relief Valves, however this simple design can still be seen today on Pressure Cookers. Like all control valves maintenance is vital, failure to keep your Pressure Relief Valve clean and working properly can put unnecessary strain on your Hot Water Heater or Boiler and could be very dangerous to your system. A pressurised system which operates with faulty or damaged safety valves can be like a ticking time bomb to its owner. All manufacturers advise that your pressurised system should be maintained annually to ensure that all safety devices are working correctly. At Advanced Water we offer Pressure Relief Valves which are set at manufacturers pressures and also we offer a range of Pressure Relief Valves which can be set at your own desired pressure up to a maximum of 12 Bar (180 PSI), should you require further assistance in regards to which Pressure Relief Valve you require please contact our technical sales team. As we offer Pressure Relief Valves from many different manufacturers we have listed below some useful links to the manufacturers which we supply, here you should be able to find a suitable valve for your requirements.