The 21000 Series Valve have a unique "reverse flow" porting design that permits equal pressure distribution on both sides of the diaphragm, regardless of line pressure providing zero stress to prevent "stretching," a common cause of valve failure. The reverse flow is also designed for water conservation in the event of failure. The diaphragm has self cleaning ports that constantly flex, inhibiting sand and silt from blocking valve action. Some other features are a brass shock cone for smooth operation and reduction of water hammer, and an easy-to-use internal manual bleed lever; bleeds valve downstream; has stops for open and closed positions.
