The 768 relief valve is designed for water and other non-corrosive liquid applications. It is fitted with a closed cap to prevent any fluid from escaping out the top. Both the body and the trim are bronze. The 768 are designed to automatically discharge when a predetermined upstream pressure is exceeded to prevent damage caused by over-pressurization. Before despatch, all safety and relief valves are tested and adjusted to the required blow-off pressure, and each valve is supplied with a test certificate.