Sometimes called Sand Shark . Easily and efficiently allows the washing down or jetting of Brady well screens for shallow irrigation wells. Wash down valves attach to any 1-1/4" or 2" well screen or casing. Internal Female threads allow for easy 1-step washdown when attached to any source of water pressure (usually a garden hose). When water pressure is removed, after you have washed to desired depth, the internal valve seals off the bottom to prevent sand from entering.