Safety relief valves are used for pressure control and protection for boilers, hot water cylinders & plumbing systems. When the calibrated pressure is reached, the valve opens and discharges the excess pressure which would be dangerous for the boiler and the components in the system itself. The valve should be fitted as close to the boiler as possible, and should incorporate a pipe connection to the outlet which enables discharge to a point outside of the building. It should discharge in a position which is noticeable, BUT NOT where any discharge may cause bodily injury. The valves are fitted with a red cap, which when rotated one third of a revolution in an anti-clockwise direction, will momentarily open the valve allowing a small discharge of water, and then abruptly close again. This procedure should be carried out after installation to ensure that the valve is functioning correctly. The safety relief valve are available with or without a pressure gauge fitted and are also available for solar heating systems.