Back Check Valves: Eliminates counter advancement and backtracking between deliveries. It works by ensuring the delivery hose is always packed with fuel. Also included built in pressure relief.
Spring Loaded Check Valves: Provides back pressure to increase air/vapor eliminator efficiency and to prevent reverse flow.
Materials of Construction: Aluminum (Back Check) & Cadmium plated steel (spring loaded check), Back check valves are rated to 350psi.