Spring closes the disc before flow reversal, preventing surge and water hammer
-Mating surfaces of the disc and seat are hand lapped for best possible sealing.
-Disc is fully guided at top and bottom to insure alignment and sealing at any installation angle.
-Disc begins to open at .5psi.
-Disc opens 1/3per inch of line size, greater than similar competitive products, for enhanced flow.
-Bodies are designed to accommodate 110% flow of equivalent pipe size.
