TWO-POSITION GATE AND SPRUNG GATE VALVES HAVING A FULL-FLOW OPEN POSITION AND A RESTRICTED-FLOW OPEN POSITION

摘要

A two-position gate valve has a gate defining a full-flow passageway therethrough and defining a restricted-flow passageway therethrough, without defining a closed position. The full-flow passageway has an entrance with a first area and an exit with a second area, the second area being smaller than the first area, and the full-flow passageway continuously tapers from the entrance to the exit thereof. The restricted-flow passageway has an entrance with a third area and has an exit with a fourth area, the fourth area being smaller than the first area, the second area, and the third area, and the restricted-flow passageway continuously tapers from the entrance to the exit thereof. Flow through the full-flow passageway is in a first direction and flow through the restricted-flow passageway is also in the first direction and the ratio of the fourth area to the second area is in a range of 5 to 15.