Abstract: A drain valve assembly for positively sealing an aircraft waste system drain line to prevent waste fluid leakage and the formation of so-called "blue ice" due to such leakage during high altitude flight. The valve assembly has an inlet for connection to the drain line, an outlet for connection to a waste drain hose of an airport waste disposal facility, and an outer valve cover and inner ball valve between the inlet and outlet which provide truly redundant seals for the drain port in flight, can be opened with relative ease when frozen, are relatively immune to improper sealing due to obstruction by waste, enable removal of a frozen waste blockage in the waste flow path without a sudden large waste dump, and permit inspection and easy replacement, if necessary, of the valve seals.

Abstract: An improved valve of the class referred to as capacity fuse valves which closes in response to passage of a total fluid flow volume through the valve to the valve outlet. The incoming fluid entering the valve inlet is split into a main flow that passes through a variable main flow metering port to the valve outlet and a control flow that passes through a variable control flow metering orifice and is utilized to close the valve upon passage of a predetermined main flow volume (main flow valve closure volume) through the valve. The areas of the main flow metering port and the control flow metering orifice are varied in response to the fluid inflow rate into the valve inlet and/or fluid temperature in such a way as to maintain a substantially fixed ratio between the main flow rate and the control flow rate, and thereby a substantially constant main flow valve closure volume, over a range of fluid inflow rates and/or temperatures.

Abstract: A drain valve assembly for positively sealing an aircraft waste system drain line to prevent waste fluid leakage and the formation of so-called "blue ice" due to such leakage during high altitude flight. The valve assembly has an inlet for connection to the drain line, an outlet for connection to a waste drain hose of an airport waste disposal facility, and an outer valve cover and inner ball valve between the inlet and outlet which provide truly redundant seals for the drain port in flight, can be opened with relative ease when frozen, are relatively immune to improper sealing due to obstruction by waste, enable removal of a frozen waste blockage in the waste flow path without a sudden large waste dump, and permit inspection and easy replacement, if necessary, of the valve seals.

Abstract: An improved valve of the class referred to as capacity fuse valves which closes in response to passage of a total fluid flow volume through the valve to the valve outlet. The incoming fluid entering the valve inlet is split into a main flow that passes through a variable main flow metering port to the valve outlet and a control flow that passes through a variable control flow metering orifice and is utilized to close the valve upon passage of a predetermined main flow volume (main flow valve closure volume) through the valve. The areas of the main flow metering port and the control flow metering orifice are varied in response to the fluid inflow rate into the valve inlet and/or fluid temperature in such a way as to maintain a substantially fixed ratio between the main flow rate and the control flow rate, and thereby a substantially constant main flow valve closure volume, over a range of fluid inflow rates and/or temperatures.

Abstract: A drain valve assembly for positively sealing an aircraft waste system drain line to prevent waste fluid leakage and the formation of so-called "blue ice" due to such leakage during high altitude flight. The valve assembly has an inlet for connection to the drain line, an outlet for connection to a waste drain hose of an airport waste disposal facility, and an outer valve cover and inner ball valve between the inlet and outlet which provide truly redundant seals for the drain port in flight, can be opened with relative ease when frozen, are relatively immune to improper sealing due to obstruction by waste, enable removal of a frozen waste blockage in the waste flow path without a sudden large waste dump, and permit inspection and easy replacement, if necessary, of the valve seals.