Abstract:
A pipe fitting is connected in a conduit from a source of fluid under pressure. The pipe fitting comprises a tubular body defining an elongate interior chamber open at both an upstream end and a downstream end. The wall of the body defines a plurality of radial passages opening into the interior chamber and extending through the wall at an acute angle relative to the longitudinal axis of the body. The passages open to the atmosphere through the wall axially spaced upstream from the passage openings into the interior. Fluid flows through the body from the upstream end to the downstream end without escaping through the passages. When fluid flow is blocked downstream of the body, backflow of fluid is directed radially outwardly and angularly upstream through the passages to the atmosphere.

Description:
BACKGROUND 
       [0001]    This application relates generally to a pipe fitting, and more particularly to a pipe fitting for use in a discharge or drainage system from a source of fluid, such as a water heater. 
         [0002]    A conventional residential water heater typically comprises a water tank that is electrically heated or heated using natural gas. For safety reasons, the water heater must be vented to release fluid if the temperature or pressure within the tank becomes too high. This is accomplished using a temperature or pressure relief valve that exits to the exterior of the tank. The relief valve is configured to be attached to a conventional standpipe for carrying away the discharged fluid. For example, as schematically shown in  FIG. 1 , a drainage system  50  comprising the standpipe is used in conjunction with the relief valve for conducting the fluid from the water heater  52  via a conduit or discharge pipe  54  to outside of a building  56 . In a high temperature or high pressure situation, fluid is vented from the relief valve and flows through the discharge pipe. 
         [0003]    A disadvantage to the arrangement described above is that the outlet of the drainage system is exposed to the environment. There are circumstances when the outlet of the discharge pipe becomes plugged by dirt or other contaminants, or the discharge pipe opening may be frozen closed. This prevents an exit path for the fluid conveyed through the discharge pipe. As a result, there is no temperature or pressure relief vent for the water heater. 
         [0004]    The International Code Council (“ICC”) plumbing code requires that fluid discharge must be provided through an air gap in the same room as the water heater either onto the floor, into an indirect waste receptacle, or outdoors. In many applications, this requirement is met with the standpipe interposed between the relief valve and the outlet of the discharge pipe for safe release of fluid when the drainage system is blocked. In one configuration for accomplishing the required air gap, a pipe leading from the relief valve is inserted into a discharge pipe of larger diameter. For example, an end of a ¾ inch pipe leading from the relief valve may be inserted into a 1½ inch pipe leading to outside of the building. Another arrangement includes using a 1½ to 1¼ inch reducing coupling upside down and running 1¼ inch pipe to outside. Both arrangements provide an air gap that complies with ICC plumbing code requirements. However, neither provides a secure connection, including a mechanical break in continuity potentially allowing for relative movement, and both result in fluid being expelled in the interior of the building. 
         [0005]    For the foregoing reasons, there is a need for a more secure pipe fitting for use in a discharge system form a source of fluid that meets plumbing code requirements. Ideally, the new pipe fitting will convey fluid away from the source of fluid in temperature and pressure relief situations. 
       SUMMARY 
       [0006]    A pipe fitting is provided for connection in a conduit from a source of fluid under pressure. The pipe fitting comprises a tubular body defining an elongate interior chamber open at both an upstream end and a downstream end. The wall of the body defines a plurality of radial passages opening into the interior chamber and extending through the wall at an acute angle relative to the longitudinal axis of the body. The passages open to the atmosphere through the wall such that the passage openings into the interior are axially spaced downstream from the passage openings to the atmosphere. Means are provided for connecting the ends of the body in the conduit for providing a fluid flow path through the body substantially coextensive and coaxial with the conduit. Fluid flowing through the body from the upstream end to the downstream end passes along the flow path without escaping through the passages. When fluid flow is blocked downstream of the body, backflow of fluid is directed radially outwardly and angularly upstream through the passages to the atmosphere. 
         [0007]    A fluid discharge system is also provided, comprising a fluid heating appliance including a fluid reservoir and a valve adapted to be connected to an outlet of the appliance for selectively discharging fluid in response to temperature or pressure conditions upstream of the valve. A tubular fitting defines an elongate interior chamber having an inlet at an upstream end and an outlet at a downstream end. The upstream end of the fitting is secured to a downstream end of the valve and the downstream end of the fitting is secured to an upstream end of a discharge conduit for providing a flow path through the chamber substantially coextensive and coaxial with the discharge conduit. The wall of the fitting defines a plurality of radial passages opening into the interior chamber in fluid communication with the flow path and extending through the wall at an acute angle relative to the longitudinal axis of the fitting upstream of the flow path and opening to the atmosphere such that the openings into the flow path are downstream from the openings to the atmosphere. Fluid discharged from the valve passes through the fitting from the inlet to the outlet along the flow path without escaping through the passages. When the discharge conduit downstream form the fitting is blocked from fluid flow, backflow of fluid is directed radially outwardly and angularly upstream through the passages to the atmosphere. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a more complete understanding of the pipe fitting, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings: 
           [0009]      FIG. 1  is schematic view of a building including a water heater with a discharge pipe to the exterior of the building. 
           [0010]      FIG. 2  is a perspective view of a pipe fitting for use in the discharge pipe as shown in  FIG. 1 . 
           [0011]      FIG. 3  is an elevation view of the pipe fitting as shown in  FIG. 2 . 
           [0012]      FIG. 4  is a top end view of the pipe fitting as shown in  FIG. 3 . 
           [0013]      FIG. 5  is a bottom end view of the pipe fitting as shown in  FIG. 3 . 
           [0014]      FIG. 6  is perspective view of the pipe fitting as shown in  FIG. 2  connected in a discharge system to a pressure relief valve in fluid communication with a water heater. 
           [0015]      FIG. 7  is a longitudinal cross-section view of the connected pipe as shown in  FIG. 6 . 
       
    
    
     DESCRIPTION 
       [0016]    Certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGs. Indeed, the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise. 
         [0017]    It is understood that, although a pipe fitting will be described in detail herein with reference to an exemplary embodiment of the pipe fitting for use with a water heater, the pipe fitting may be applied to, and find utility in, other pressure and temperature relief applications from a fluid source. Pressure relief valves for expelling fluid are used in a wide variety of devices and appliances such as, for example, water conditioners, water filters, washing machines, ice making machines, commercial dishwashers and the like, which operate with fluid under legated temperature or pressure conditions. Thus, the pipe fitting has general applicability in any configuration wherein improvements in fluid discharge are desired. 
         [0018]    Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, an embodiment of a pipe fitting is shown in  FIGS. 2-5  for connection in a discharge pipe from a source of fluid, and generally designated at  10 . The pipe fitting  10  comprises a cylindrical tubular body  12  having a longitudinal axis. The pipe fitting  10  is preferably formed from metal, but can be made of plastic, particularly where it may be necessary to bond it to plastic drain pipe. 
         [0019]    The body  12  has an upstream end  14  and a downstream end  16  and the interior of the body defines an axial bore  18  for fluid flow. The upstream end  14  is provided with a male externally threaded portion  20  and the downstream end  16  is provided with a female internally threaded portion  22 . As described in more detail below, the male threads  20  are adapted to threadably connect to the female threads of a conventional union fitting carried by a downstream portion of a discharge pipe, and the internally threaded downstream end of the body is adapted to threadably connect to the male threads provided on the upstream portion of the discharge pipe. In another embodiment, both ends  14 ,  16  of the body  12  of the pipe fitting  10  may be similarly threaded. In addition, the body  12  may have suitable wrench flats (not shown) disposed about the circumference of the body to receive a wrench to rotate the pipe fitting  10 , or resist rotation of the pipe fitting, as needed for enabling tightening and removal of screwed couplings or pipe fittings to either end  14 ,  16  of the body  12 . 
         [0020]    Although the embodiments of the pipe fitting  10  shown in the drawings are configured for threaded connection with adjacent portions of a discharge pipe having threaded fittings, the pipe fitting  10  may also be adapted for connection to unthreaded pipe couplings. For example, for discharge pipes comprising plastic pipe, conventional connecting plastic sleeves (not shown), smeared or coated internally with adhesive, can be slipped over the ends of the body  12  and the adjacent plastic discharge pipe. Another means for coupling the pipe fitting  10  in a discharge pipe may be particularly adapted for flexible tubing. In this arrangement, the upstream end  14  of the body  12  is attached to an internally threaded cylindrical tubing adapter (not shown) using an appropriate fitting. As is known in the art, an unthreaded exterior portion of the adapter is characterized by bayonet type ridges for retaining such portion within the interior of the upstream end  14  of the body  12 . A conventional hose clamp (not shown) is employed to prevent separation of the components. A similar arrangement is used to secure connection of the downstream end  16  of the body  12  to a similar tubing adapter, except that the adapter is characterized by male threads for threadably mounting the adapter to the female threads  22  of the downstream end  16  of the body  12 . It is understood that the embodiments of the end couplings or end fittings described herein for connecting the pipe fitting  10  in a discharge pipe are merely exemplary. The pipe fitting  10  may comprise various end coupling or fitting arrangements known to those skilled in the art whereby the pipe fitting  10  can be readily connected by threaded attachment, by adhesive connection for plastic pipe, by compression fittings for flexible tubing, and the like. 
         [0021]    Intermediate the ends of the body  12  is an exterior annular shoulder  24  which projects angularly outwardly in the downstream direction. A plurality of circumferentially disposed, radially directed ports  26  are formed in the body  12  of the pipe fitting  10  downstream of the shoulder  24 . The ports  24  open into the axial bore  18  and extend to the exterior of the body  12  for providing fluid communication between the bore  18  and the atmosphere. In one embodiment, eight ports  26  are equally spaced about 45° apart around the periphery of the pipe fitting  10 . The walls of the body  12  defining the ports  26  are angled in the downstream direction defining an acute angle with the upstream longitudinal axis of the body  12 . The angled ports minimize escape via the ports  26  of fluid normally flowing downstream through the bore  18 , taking advantage of the kinetic energy of the fluid flow. As described below, the ports  26  function when the discharge pipe is blocked to provide backflow passages for discharging fluid in a plurality of centrifugal radial directions. In one embodiment, the sum of the cross-sectional area of all of the ports is substantially equal to the cross-sectional area of the bore  18 . 
         [0022]    In one embodiment, the pipe fitting  10  is adapted for mounting directly into a discharge system of a conventional water heater  30 . As shown in  FIGS. 6 and 7 , the male threads  20  of the upstream end  14  of the body  12  are threadably connected to a female threaded downstream opening of a relief valve  32  for establishing a threaded connection between the pipe fitting  10  and the relief valve  32 . The internally threaded downstream end  16  of the body  12  is threadably connected to male threads provided on the upstream end of the standpipe  34  of a discharge pipe. Teflon tape  36  may be disposed on the male threads  20  of the body  12  to provide a fluid tight connection. When connected, a continuous axial opening ( FIG. 7 ) is formed from the relief valve  32  and through the bore  18  of the body  12  of the pipe fitting  10 . The axial opening has a diameter substantially the same as the internal diameter of the standpipe so as to provide a smooth flow path. Moreover, the outside diameter of the discharge pipe is also the same. 
         [0023]    In the application shown in the FIGs., the pipe fitting  10  is disposed vertically. It is understood that the pipe fitting  10  is also operable in other orientations, including horizontal and various angular orientations between vertical and horizontal. The vertical orientation is a typical application, but an angular mounting of the pipe fitting  10  may be preferred for applications involving space constraints. 
         [0024]    In operation, the relief valve  32  is adapted to open upon attainment of a predetermined pressure or temperature within the interior of the water heater  30 . When the relief valve  32  is open, fluid, in this case hot water or steam, is permitted to flow through the pipe fitting  10  in the downstream direction and into the standpipe  34  as illustrated by an arrow  38  in  FIG. 7 . If the discharge pipe is not blocked, the pipe fitting  10  provides a smooth flow path for the fluid through the pipe fitting. Because the walls of the body  12  defining the ports  26  are angled downstream, fluid does not exit the pipe fitting  10  through the ports  26  under normal fluid discharge conditions. Thus, high pressure and high temperature in the water heater  30  are avoided. 
         [0025]    Should the discharge pipe be clogged such that fluid exiting the water heater  30  through the relief valve  32  cannot advance, the fluid will back up in an upstream direction into the pipe fitting  10 . The backed up fluid under pressure will escape the pipe fitting  10  through the ports  26 . As illustrated by the arrows  40  in  FIG. 7 , this condition results in an angularly outward discharge of fluid through the ports  26  to the atmosphere. 
         [0026]    Thus, there has been described embodiments for a pipe fitting  10  which can be used in a fluid discharge system in conjunction with a relief valve  32  for protection against high pressure and temperature conditions in which fluid under pressure must be vented to the atmosphere. The pipe fitting  10  is operable to prevent fluid from escaping through the ports  26  during normal fluid discharge conditions. The pipe fitting  10  is configured for easy attachment to conventional pipe, and can readily accommodate various conventional plastic, copper, brass or steel adapter fittings typically provided as off-the-shelf items for installing the fluid discharge system. The embodiments of the pipe fitting  10  described herein provide a rigid discharge pipe connection that ensures a safe and professional installation. Users are provided with a necessary plumbing connection to satisfy plumbing codes, and which will obviate the practice of the installer creating a custom on-site connection with air gap that is less reliable. The pipe fitting  10  is readily adaptable for use or re-use in retrofit situations in order to bring existing discharge pipes, such as for water heaters, up to code. 
         [0027]    Although the present invention has been shown and described in considerable detail with respect to only a particular exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiment since various modifications, omissions and additions may be made to the disclosed embodiment without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, the pipe fitting may be used in any water heating appliance or other source of fluid under elevated pressure or temperature conditions. Accordingly, we intend to cover all such modifications, omission, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.