An apparatus to allow or stop an air flow into an enclosed environment or piping system comprises (a) a housing, (b) a first valve seat, (c) a first sealing member, (d) a second valve seat, (e) a second sealing member, (f) at least one locking mechanism configured to limit a movement of the first sealing member and/or the second sealing member; wherein the first sealing member moves away from the first valve seat when the second pressure is greater than the first pressure in a predetermined pressure difference; wherein the second sealing member moves away from the first valve seat when the third pressure is greater than the second pressure in a predetermined pressure difference; wherein the first pressure communicates with a system pressure in the piping system; and wherein the third pressure communicates with an ambient air pressure.

The present disclosure provides a return gas prevention device for a drainage pipe, belonging to the technical field of drainage pipes. The device realizes two functions of water seal and a check valve simultaneously, as well as prevents gas channeling in a drainage process.

Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly comprising a housing, a first valve comprising a first valve sealing member and a first valve seat, and a second valve comprising a second valve sealing member and a second valve seat, and a pipe, an inlet, an outlet, a first zone, a second zone, a third zone, the first and second valve sealing member is closed by gravity and open based upon the pressure differential between the first zone, second zone and third zone.

A drain pipe connector adapted to be disposed between a drain portal of a plumbing fixture and a sewage pipe. The drain pipe connector includes a first unidirectional valve adapted to be in fluid communication with the drain portal, and a drain trap in connected to the first unidirectional valve and adapted to be connected to the sewage pipe. The first unidirectional valve has a closed operative orientation, in which the first unidirectional valve forms a seal between the drain portal and the drain trap, and an open operative orientation which enables flow of fluid from the drain portal, via the first unidirectional valve, into the drain trap. The first unidirectional valve is normally closed, and when liquid drains into the first unidirectional valve, pressure applied by the liquid transitions the first unidirectional valve from the closed operative orientation to the open operative orientation, thereby enabling the liquid to flow into the drain trap.

An apparatus to allow or stop an air flow into an enclosed environment or piping system comprises (a) a housing, (b) a first valve seat, (c) a first sealing member, (d) a second valve seat, (e) a second sealing member, (f) at least one locking mechanism configured to limit a movement of the first sealing member and/or the second sealing member; wherein the first sealing member moves away from the first valve seat when the second pressure is greater than the first pressure in a predetermined pressure difference; wherein the second sealing member moves away from the first valve seat when the third pressure is greater than the second pressure in a predetermined pressure difference; wherein the first pressure communicates with a system pressure in the piping system; and wherein the third pressure communicates with an ambient air pressure.

A water drain management apparatus used in clinical facility (43) or other facility includes a manifold plumbing fitting (32, 272, 384). The fitting includes a plurality of drain outlet connections for water discharge devices (40, 42, 222, 226, 230, 234). Such water discharge devices may include devices such as autoclaves, sterilizers, cleaners, washers, filters, humidifiers, condensing devices and other devices used in the facility. A plurality of drain fitting openings in the body of the fitting are connectable to respective water discharge devices, and openings that are not utilized are closable with plugs. Some manifold fittings (272, 344, 384, 482) include an air gap opening (288, 360, 392, 530). These configurations provide an air gap that prevents contamination due to back flow of water within the fitting reaching water discharge devices or the body inlet of the manifold fitting.

A water drain management apparatus used in clinical facility (43) or other facility includes a manifold plumbing fitting (32, 272, 384). The fitting includes a plurality of drain outlet connections for water discharge devices (40, 42, 222, 226, 230, 234). Such water discharge devices may include devices such as autoclaves, sterilizers, cleaners, washers, filters, humidifiers, condensing devices and other devices used in the facility. A plurality of drain fitting openings in the body of the fitting are connectable to respective water discharge devices, and openings that are not utilized are closable with plugs. Some manifold fittings (272, 344, 384, 482) include an air gap opening (288, 360, 392, 530). These configurations provide an air gap that prevents contamination due to back flow of water within the fitting reaching water discharge devices or the body inlet of the manifold fitting.

A positive air pressure attenuation device (1) comprising:—a housing (3) with an inner central portion (6) forming a channel (7); and an elastic flexible inflatable reservoir (8) associated to the inner central portion (6), whereby the inner central portion (6) has a wall portion (60) with a plurality of openings (61) forming passages between the channel (7) and the reservoir chamber (8A).

Embodiments of a valve assembly and a plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly for use with an enclosed environment includes a housing having an interior volume, an inlet disposed at a first end of the housing and fluidly coupled to an environment surrounding the housing, and an outlet disposed at a second end of the housing opposite the first end and fluidly coupled to the enclosed environment; a first valve having a first valve seat and a first sealing member at least partially extending through a first opening in the first valve seat in a closed position; and a second valve disposed beneath the first valve and having a second valve seat and a second sealing member at least partially extending through a second opening in the second valve seat in a closed position.

The present disclosure provides a return gas prevention device for a drainage pipe, belonging to the technical field of drainage pipes. The device realizes two functions of water seal and a check valve simultaneously, as well as prevents gas channeling in a drainage process.