Patent ID: 6425145
Filing Date: 2002-07-30
Classification: E03D

Abstract:
A pressure-responsive valve system comprising:A) a delayed-closure valve forming a valve outlet and a valve inlet through which fluid can be introduced into the valve at an inlet pressure, the delayed-closure valve being operable from a closed state, in which the delayed-closure valve prevents flow therethrough from the valve inlet to the valve outlet, through a range of open states, in which it permits such flow, the delayed-closure valve being so biased that, after release from a given open state, it returns to the closed state after a closure delay that varies with how far the given state is into the range of open states; B) a valve operator biased to a retracted position, in which it permits the delayed-closure valve to remain in its closed position, and manually operable through a range of extended positions, in each of which it holds the valve in corresponding open states within the range thereof; C) an operator stop forming a stop pressure chamber and being resiliently expandable by pressurization of the stop pressure chamber, the operator stop being positioned to reduce the range of the valve operator's extended positions as the operator stop expands; and D) a pressurizer conduit so extending from the valve inlet to the stop pressure chamber that the stop pressure chamber receives the inlet pressure, whereby the closure delay decreases with increases in inlet pressure.