T-Rex VAS-80RG 80 mm 3 inch diaphragm shut-off valve with 80 mm (3 inch) roll groove portsT Rex VAS 80RG 80 mm 3 inch diaphragm shut off valve 80 mm (3 inch) roll groove ports Applications: medium flow applications side batter sprays road washing sprays pressurised dribble bars Valve operation: operates opposite to a butterfly valve due to the use of a convex diaphragm air pressure maintains this valve in a closed position removing the air pressure and applying at least 1. 4 bar (20 psi) of water pressure will lift the diaphragm allowing