Patent Application
20120305085
The present invention generally relates to primers for floor drain systems.
Because of its shape, a drain trap retains a small amount of water after the fixture's use. This water in the trap creates a seal that prevents sewer gas from passing from the drain pipes back into the occupied space of the building. Maintaining the water seal is critical to trap operation and for ensuring building safety by preventing a back up into the building of sewer gas. Unfortunately, but because the water in a drain trap is exposed to the air, it is subject to evaporation over time in infrequently used floor drains, leading to the release of sewer gas into the environment. A trap primer (or trap seal primer) is a plumbing device or valve that adds water to traps. The trap primer mitigates this problem of evaporation by injecting water, either directly or indirectly, into the trap to maintain the water seal indefinitely.
Building codes require the use of trap primers. For example, Section 7.2.3 of the Ontario Building Code 1997 every trap is required to have a trap seal for some traps, especially for where experience has shown that there are isolated and/or infrequently used drains such as basement floor drains (which are only used when the basement is flooded). Where explosion hazards are high, specifying trap primers, whether required or not by code, is wise. Trap primers do require maintenance and replacement, so they should be installed in accessible locations.
There are many types of trap primers. The simplest, typically for a floor drain's trap, is simply a connection from a nearby sink's drain so that when the sink is used, some of the water flow is diverted into one or more traps. More common is a primer that is connected to the potable water supply and activates when pressure fluctuations are sensed, such as the flushing of a nearby water closet.
As illustrated in
Continuous flow trap seal primers are the original style of trap seal primers.
They are typically constructed of cast brass or bronze with a neoprene rubber poppet float on the inside that rises upward as water flows through the primer. When the poppet rises off of its seat, water flows from the primer, through the plumbing line connection, and into the floor drain trap. They are manufactured in either sweat, threaded or union connections and should be installed in a vertical position within the horizontal water supply line, at least ten inches above the floor drain trap that it serves. Continuous flow trap seal primers do not have any method of screening out line debris. This often results in their clogging and either flowing water continuously, or not at all. The volume of water that they discharge is directly related to the amount of water that continuously flows through them. For these reasons, pressure drop activated trap seal primers have become the selection of choice for specifiers.
Factors such as type of trap seal primer, installation considerations, and local code requirements must be taken into account when specifying trap seal primers. The A.S.S.E. (American Society of Sanitary Engineers) Standards are the recognized standard for trap primers in the USA and in Canada. The A.S.S.E. Standard is referenced in Plumbing Codes. The ASSE 1018 is the key standard relating to trap seal primers. It dictates a method of priming traps using a potable water supply to the trap primer device. It provides intermittent discharge to the trap in response to the flow or pressure changes in the supply line.
Pressure drop activated trap seal primers are typically manufactured out of brass. They are engineered with an inlet and an outlet connection. They have an interior cartridge that seals when the line pressure is in a static state. When the line pressure drops as little as three pounds per square inch, which can be caused by the flushing of a toilet, opening of a faucet, or any draw of water from the water supply line within a close distance to the primer, the interior cartridge will rise due to the pressure differential within the primer. A metered amount of water, typically about 0.75-1.75 ounces per activation is discharged under pressure into the plumbing line connected to the floor drain trap. Pressure drop activated trap seal primers are supplied with a fine mesh brass filter that will screen out debris to ensure that the cartridge is not clogged and that the water deliveries are uniform. The filter is easily accessible for quick cleaning or replacement. Pressure drop activated trap seal primers are relatively expensive and a separate primer must be installed at the water feed for each drain trap. There are some pressure drop seal primers which incorporate a manifold for connection of 4 or 6 supply lines to nearby drain traps, but manifold primers are only of modest benefit in larger installations which might have upwards of 12 drain sites. Multiple manifold primers would still be required to complete such a project. Considerable care must be taken when installing the pressure drop primers which have manifolds in order to make sure that the lines to the nearby are level with one another so that water will flow evenly into all supply lines and be carried to each of the traps.
Flush valve trap seal primers are installed below the flush valve and direct an amount of waste water discharged from the flush valve into a tube that connects to the floor drain to maintain the water seal. Their advantages are that the water used is already consumed by the flush valve operation, and this type of primer has no moving parts. Their disadvantage is that their location is determined by the location of the fixtures which may be too far away from the floor drains to be practical, unlike supply line mounted trap seal primers which can be more easily installed close to the drain to be primed. Many installations cannot use flush valve trap seal primers because the floor drain traps are too far away to be reached by the flush valve trap seal primer.
It is an object of the present invention to provide a drain trap primer system that can be installed in situations where the drain trap is located a significant distance from the water source.
It is another object of the present invention to provide a drain trap primer system which does not rely on gravity to carry water to a drain trap, and which need not be mounted above a drain trap.
It is a further object of the present invention to provide a drain trap primer system which is reliably provides water to multiple drain traps in a serviced area.
It is a further object of the present invention to provide a drain trap primer system which does not require the use of multiple primers to service multiple traps, and which can be installed to service traps which are not on the same level.
In accordance with the present invention, a drain trap primer system comprises a water supply line for fluid connection between a pressurized water source and a drain trap. A valve which is operable between an open position and a closed position is in fluid connection within the supply line. An actuation means is provided for switching the valve between the closed position and the open position, and a control mechanism signals the actuator to open and close the valve at selected time intervals.
A method of using a pressurized water source to prime a drain trap comprises the steps of connecting a solenoid valve into a water supply line; providing a timer to operate the solenoid valve; connecting the water supply line to a drain trap; and, connecting the water supply line to a pressurized water source.
A method of scheduling the priming a drain trap comprising the steps of storing a routine comprising a plurality of time intervals and a corresponding on or off signal for each time interval; executing the routine; determining a current time interval of the executing routine; determining the on or off signal corresponding to the current time interval of the executing routine and; and sending an on or off signal to one a solenoid valves in fluid connection in a line between a pressurized water source and one or more drain traps if the current signal corresponding to the current time interval comprises an on signal or an off signal.
The drain trap primer system of the present invention is shown in a schematic view in
A valve 18 which is operable between an open position and a closed position is installed in fluid connection within the supply line 12. An actuation means is provided for switching the valve 18 between the closed position which would prevent the flow of water, and the open position which permits the flow of water through the supply line 12 to the trap 16. A control mechanism is necessary for signaling the actuator to open and close the valve 18 at selected time intervals. There preferred manner of providing a valve and actuation means is to use a solenoid value. The control mechanism comprises a timer 20 and a signal relay 22. The timer 18 may be selected from the group consisting of mechanical timer, electromechanical timer, electronic timer, and digital timer. It is preferred to use a digital timer system which can be readily integrated with the solenoid valve 18 to efficiently and precisely control its opening and closing for brief periods of time to flush water into the drain trap(s) at desired intervals. Digital timer/solenoid valve combinations are known and used in the irrigation and greenhouse industries to provided timed watering cycles for plants. An example is the ORBITâ„¢ sprinkler timer available from Orbit Irrigation Products Inc. of North Salt Lake, Utah, USA. Such a digital timer and solenoid valve can advantageously be used in the present invention.
The solenoid valve 18 is connected in fluid connection within the water supply line 12. Although not necessary, a manual shutoff valve 22 may also be installed upstream of the solenoid valve so that the water supply to the solenoid valve can be turned off for servicing or troubleshooting purposes. The timer 20 is provided to operate the solenoid valve 18. Multiple solenoid valves 18 may be connected to a single timer 20. Each solenoid valve has two wires, one to be connected between the valves in common, and the other a station terminal on the timer. A second manual shutoff valve 24 may be installed in the supply line 12 downstream of the solenoid valve 18 to facilitate servicing. The water supply line is connected to the drain trap(s) to permit water to flow from the water supply line 12 in to the trap(s) when the solenoid valve is opened. The water supply line 12 is connected to the pressurized water source 14. The supply lines feeding water to the drain traps may feed from one another as shown in
In an alternate embodiment shown in
The flow of water to the drain traps 16 can be controlled to meet the particular needs for each drain trap in an installation. The primer system according to the present invention has the ability to have a maximum flow rate of incoming water pressure to match the building's supplied water pressure, for example (70 psi), with a timer activation pattern calculated to provide the desired supply of water to each trap. For example, one minute flow duration at 70 psi would supply a volume of 201 oz of water; whereas at a minimum pressure of 5 psi, the one minute flow would supply an 8 oz volume of water. The number of drain traps connected in a particular supply line, and the volume of water required by each drain would be used in setting a water supply schedule. The water supply schedule could be set to deliver water daily, weekly or at any other desired interval. In very hot locations where there is rapid evaporation of standing water, the water delivery interval could be shorter, the volume of water delivered in each supply occasion could be greater, or a combination of these parameters could be used. Adjustment could be made for cooler or moister environments with slower evaporation by increasing the interval of time between supply occasions and/or decreasing the volume of water supplied on a given occasion.
Even more finely adjusted control of the water delivery to drain traps is possible with the connection of one or more pressure throttles 26 into the subsidiary supply lines 13. A pressure throttle 26 connected into the subsidiary supply line will reduce the water pressure fed into that particular subsidiary supply line, which will result in a smaller volume of water flowing to the drain trap 16 which is fed by that subsidiary line, since it continues to receive water for a particular time interval, but at a lower pressure and flow rate. Pressure throttles 26 can be advantageously used in systems which connect many drain traps at varying distances from the water source and supply line 12. Greater pressure would be necessary to carry water to distance traps. The supply interval set at the controller would remain constant, but the use of a throttle to reduce pressure in subsidiary supply lines to nearby traps would prevent nearby traps from being over filled (resulting in waste), while still adequately supplying more distant traps through subsidiary supply lines set at higher water pressures. The use of throttles can also permit the use of a single trap priming system to efficiently supply drain traps in different environments (hot and dry vs. cool and damp). In this instance pressure would be throttled down in the subsidiary supply line(s) feeding traps in the cool and damp areas, in order to provide less water while still being connected to a system which is capable of concurrently maintaining water barriers in other environments which have greater evaporative demand.
In use, the drain trap primer system will carry out a method of scheduling the priming of a drain trap comprising the steps of storing a routine comprising a plurality of time intervals and a corresponding on or off signal for each time interval; executing the routine; determining a current time interval of the executing routine; determining the on or off signal corresponding to the current time interval of the executing routine and; and sending an on or off signal to a solenoid valve in fluid connection in a supply line between a pressurized water source and one or more drain traps if the current signal corresponding to the current time interval comprises an on signal or an off signal.
While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims.
