Description: Non Return Valves are available in square or hexagonal straight pattern design with puppet-type steel construe lion Viton moulded `O' ring thread retainers permits varia lion in cracking pressures from 5 to 50 PSI. These valves are built using different materials. It allows free flow in one direction and zero leakage closer in opposite direction. These valves are widely used for air and gas application. It workes with a pressure of up to 500bar and is available with optional end conenction of sizes ranging from ¼″ NB to 2″ NB.