C80 Series Airbleed Priming Valves automatically open to allow F/G-20 through D/G-12 Series Hydra-Cell pumps to self-prime by quickly relieving the system of trapped vapors or air, rather than compressing the gas and causing pump airlock. The valves then automatically close to provide immediate full system pressure. These easy-to-install valves are available in a variety of materials of construction and mount horizontally or vertically to satisfy various application requirements.