Abstract: A method and apparatus for admitting liquid from a draining surface into a drain conduit and for preventing discharge of waste gas from the drain conduit into the atmosphere in response to a higher pressure in the drain conduit than at the draining surface. The method and apparatus typically are for use draining floors, basements, roofs, countertops, exterior paved areas, and surfaces draining into line that could discharge waste gas back into the environment. The invention provides floor drain assemblies and check valves with good drainage performance with out the use of P or U-traps, and is particularly well suited for use when drainage occurs irregularly. Floor drains according to the invention comprise check valves adapted for disposition within floor drains, the check valves generally comprising spring-loaded stops, elastic diaphragms, or sheath valves. Check valves according to the invention are preferably installable in existing drain structures, and are easily removable.

Abstract: A method and apparatus for admitting liquid from a draining surface into a drain conduit and for preventing discharge of waste gas from the drain conduit into the atmosphere in response to a higher pressure in the drain conduit than at the draining surface. The method and apparatus typically are for use draining floors, basements, roofs, countertops, exterior paved areas, and surfaces draining into line that could discharge waste gas back into the environment. The invention provides floor drain assemblies and check valves with good drainage performance with out the use of P or U-traps, and is particularly well suited for use when drainage occurs irregularly. Floor drains according to the invention comprise check valves adapted for disposition within floor drains, the check valves generally comprising spring-loaded stops, elastic diaphragms, or sheath valves. Check valves according to the invention are preferably installable in existing drain structures, and are easily removable.

Abstract: An improved floor drain for buildings, basements, exterior paved areas, and the like. The invention provides floor drain assemblies and floor drains providing improved drainage performance, particularly where drainage is an irregular occurrence, and having unprecedented simplicity and reliability. Floor drains according to the invention comprise side port drain valves adapted for disposition within floor drains, the drain valves generally comprising non-horizontal drain ports, one or more sealing surfaces disposed between the ports and a drain conduit, a stop adapted for sealing engagement of the sealing surface, and means to urge the stop into sealing engagement of the sealing surface. Floating, spring-loaded, or flexible elastic valves stops, among others, may be used; any of them may be tailored for opening under a selected hydrostatic pressure.

Abstract: An improved floor drain for buildings, basements, exterior paved areas, and the like. The invention provides floor drain assemblies and check valves providing improved drainage performance, particularly where drainage is an irregular occurrence, and having unprecedented simplicity and reliability. Floor drains according to the invention comprise check valves adapted for disposition within floor drains, the check valves generally comprising spring-loaded stops or elastic diaphragms, either of which may be tailored for opening under a selected hydrostatic pressure. Use of the check valves according to the invention permits drainage through the drain conduit while preventing back flow from the drain of undesirable or unwanted gasses. Check valves according to the invention are preferably installable in existing drain structures, and easily removable for maintenance or replacement.