Abstract: A plastic sewage holding tank in a boat, associated with a toilet, includes a vent check valve for providing vacuum relief. By mounting the vent check valve in the top of the tank, when the tank is being emptied by rapid pumpout implosion or other damage to the tank is prevented. The vent check valve may include a valve body with an interior surface mounting a quad sealing ring, with a valve element guided for reciprocal movement between a sealing position where an axially elongated substantially cylindrical peripheral surface of the valve element engages the quad ring, to an open position where the valve element is moved against spring bias away from the valve body. A spider, with a collar for guiding a shaft portion of the valve element, may mount a coil spring to provide a biasing action.

Abstract: Flexible PVC hose can be used with toilet systems in vehicles, such as boats, recreational vehicles, etc, or at pumpout stations. The hose includes about 40-55% by weight PVC resin, and at least 10% by weight of an EVA high molecular weight plasticizer. The hose also typically includes a low molecular weight plasticizer, stabilizer, lubricant, filler (such as 5-20% by weight dense filler like calcium carbonate), and pigment. The hose typically will not fail (that is will not transmit odor) for the life of the toilet system, or mechanical life of the hose.

Abstract: A vacuum toilet assembly including a vacuum toilet and a vacuum tank (e.g. a combined holding and vacuum tank) uses a simple air pump to remove air from the tank to create a partial vacuum. The air pump is capable of achieving about ten inches mercury of vacuum in an empty 9.5 gallon vacuum tank in roughly one minute, and can pump at least about one liter of liquid per minute. A combined sound muffler and odor filter and/or rat-tail check valve and noise reducer, is/are connected to the outlet from the air pump. The pump comprises a powered reciprocating diaphragm pump having a reciprocating diaphragm powered by an electric motor rotating an eccentric at about 2300 rpm, and oppositely directed first and second disk valves. The disk valves have elastomeric disk valve elements die-cut from flat sheets which cooperate with perforated concave surfaces in a dividing wall in the pump housing. The reciprocating diaphragm has a total stroke length of about 0.3-0.33 inches.

Abstract: A plastic sewage holding tank in a boat, associated with a toilet, includes a vent check valve assembly for providing vacuum relief. By mounting the vent check valve in the top of the tank, when the tank is being emptied by rapid pumpout implosion or other damage to the tank is prevented. The vent check valve assembly may include a valve body surface operatively connected to the tank and having a plurality of openings formed in it, and a flexible material diaphragm covering the openings adjacent the inside of the tank, and uncovering openings to allow air flow through the openings substantially only when a vacuum condition exists inside the tank. A plastic disk biases the diaphragm into its opening-covering position, but a partial vacuum of at least about 2-5 inches of water allows air to flow through the openings past the diaphragm.

Abstract: Flexible PVC hose can be used with toilet systems in vehicles, such as boats, recreational vehicles, etc, or at pumpout stations. The hose includes about 40-55% by weight PVC resin, and at least 10% by weight of an EVA high molecular weight plasticizer. The hose also typically includes a low molecular weight plasticizer, stabilizer, lubricant, filler (such as 5-20% by weight dense filler like calcium carbonate), and pigment. The hose typically will not fail (that is will not transmit odor) for the life of the toilet system, or mechanical life of the hose.

Abstract: A vacuum sewage handling assembly particularly for boats and recreational vehicles or caravans has a minimum of components because the conventional vacuum and holding tanks have been combined into a single substantially unreinforced, non-cylindrical, all plastic tank. The tank has a contoured, convoluted, discontinuous surface (e.g. formed by grooves, channels, and other discontinuities) so that it has no continuous flat surface area of more than about 80 square inches. The combined vacuum and holding tank may mount a vacuum pump, and optionally mounts a sewage discharge pump. The tank preferably has a generally parallelepiped configuration, and an interior volume of between about 45-65 liters, has a maximum vacuum level of about 26 cm of mercury, and is connected to other conventional portions of a vehicle toilet system, including outlets penetrating the exterior of the vehicle. The tank may have wheels and a handle.

Abstract: A marine tank (such as a toilet system holding tank, or bilge tank) pump out system includes a positive displacement pump connectable at the inlet to a marine tank to be pumped out and connectable at the outlet to a discharge tank or area. A pulsation dampener is connected between the pump outlet and the discharge tank or area, preferably directly to the pump so that a pump check valve is within the pulsation dampener. The pulsation dampener has an open chamber extending upwardly from the pump outlet into which pumped fluent material may flow, and has no moving parts (such as a diaphragm). Typically two different outlets from the dampener are provided for versatility and connecting up to discharge tanks or areas, one of the outlets filled with a plug. The dampener may comprise either a substantially L-shaped or C-shaped (when viewed from the dampener inlet) casing, which nests with the pump motor.

Abstract: A discharge hose adapter adapts a standard marine thru hull fitting to a standard sanitation hose enabling discharge of a boat holding tank into a dump station. The adapter preferably includes a first component and a second component. The first end of the first component is frictionally engageable with the standard marine thru hull fitting, a first end of the second component is engageable with the second end of the first component, and a second end of the second component is engageable with the sanitation hose. The first component is preferably PVC injection molded plastic, and the second component is preferably compression molded rubber derived from vinyl monomers.

Abstract: A sewage handling assembly particularly for boats and recreational vehicles with a minimum of components. The waste discharge of a toilet is connected to an inlet for a combined vacuum and holding tank which mounts a vacuum pump, and optionally mounts a sewage discharge pump. A sewage discharge conduit, which may be connected to the optional sewage discharge pump, is connected to a first outlet from the tank, in turn connected to a dip tube terminating in an open end just above the tank bottom. A second outlet from the tank is connected to the vacuum pump (in turn connected to a gas conduit with an end termination penetrating an exterior partition of the boat or RV), and an upwardly extending gas tube inside the tank, having an opening near the interior top of the tank, is connected to the second outlet. The tank is controlled so that a gas volume of about 2 and 1/2-4 gallons is always maintained in the tank, with a vacuum level of between about 8-10 inches of mercury.

Abstract: A particular vacuum tank construction is provided for a vacuum toilet assembly which mounts a vacuum pump, has great versatility and accessibility, and ensures optimized washing effect of water and waste into the vacuum tank. A tank inlet is located at the opposite end of the tank from a sump formed in the tank bottom, and an inlet fitting at the inlet is rotatable at least about 180.degree. about a vertical axis. Connected to a tank outlet is a dip tube assembly including a substantially rigid dip tube which has an oval shaped end termination opening which is above, but spaced from, the sump and positioned so that objects of a size that would harm the vacuum pump connected to the tank outlet cannot enter the dip tube. The tank is of plastic having a nominal wall thickness of about 5/16th inch, and no flat surface area is greater than about 80 square inches. The inlet is connected to a vacuum toilet, and the vacuum pump outlet is connected to a waste (holding) tank.