Abstract:
A tamper-resistant by-pass valve prevents an unauthorized user from tampering with the valve when it is in the closed position to block gas flow to a meter being replaced or repaired.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to by-pass valves for servicing a fluid line, and more particularly to a tamper-proof, by-pass valve for natural gas service. 
     Residential and commercial gas customers have a service stop valve for controlling gas flow to the customer. A supply conduit provides gas to the stop valve which when opened supplies gas to a meter. The gas passes to the customer from the meter through another conduit. It is sometimes necessary for the utility company to change and/or repair the meter and regulator. A by-pass valve and conduit are temporarily connected between the supply conduit and the customer connection to continue service to the customer during such a repair. 
     Prior art related to this type of service may be found in U.S. Pat. No. 6,283,153 issued Sep. 4, 2001, to Harlin J. Brisco et al. for “Flow Valve”; U.S. Pat. No. 3,187,570 issued Jun. 8, 1965, to Frank H. Mueller for “By-pass For Fluid Meter”. 
     A problem with prior art by-pass valves is that unauthorized personnel can tap into a by-pass port intended to be used as a temporary gas connection. The present invention solves this problem by providing a tamper-proof valve having two security arrangements for protecting the by-pass port. 
     Typically the by-pass valve is a ball valve having a valve stem with a rectangular operator for opening and closing the ball valve element. The preferred valve body has a by-pass port for connecting a temporary conduit to supply gas to the consumer when the ball valve element is closed. A locking wing is carried on the valve stem. When the valve handle is turned to its fully open position, the locking wing is disposed over the by-pass port, preventing an unauthorized user from using a tool to remove a security plug in the by-pass port. When the ball valve is closed, the locking wing is turned to another position permitting a by-pass hose to be connected to the by-pass port, and permitting a padlock or industry specific device to lock the valve in its closed position. 
     Another feature of the invention is that the by-pass port is at one end of an internal by-pass passage in the body of the valve. When the by-pass passage is open and the ball valve is closed, gas flows from the supply conduit through the by-pass port and the by-pass passage to the customer&#39;s supply conduit. A shutter valve is mounted in the valve body adjacent to the by-pass passage. A special tool is used to open the shutter valve, permitting gas flow through the by-pass passage. The shutter valve can be closed to block the by-pass passage, thus preventing unauthorized access to the gas flowing through the valve, by someone not having means for opening the shutter valve. 
     The security arrangements of the invention can be used on other types of valves, such as gate valves, butterfly valves and plug valves. 
     Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which: 
     FIG. 1 is a perspective view showing the preferred valve; 
     FIG. 2 is a top plan view of the preferred valve in the closed position; 
     FIG. 3 is a partially sectional view of the valve as seen along the lines  3 — 3  of FIG. 2; 
     FIG. 4 is a view similar to FIG. 2 but showing the locking wing in a position blocking access to the by-pass port; 
     FIG. 5 is a partially sectional view showing the by-pass passage and shutter valve in the open position; 
     FIG. 6 is a view similar to FIG. 5 but showing the shutter valve in the closed position; and 
     FIG. 7 is a view showing a typical gas delivery system with the by-pass valve in the by-pass condition. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, FIG. 1 illustrates a preferred tamper-proof bypass valve  10 , a locking device  12  for locking the valve in the closed position, and a tool  14  for removing a bypass plug  16  from body  18  of the valve. 
     Body  18  has a through passage  20  with an inlet opening  22  and an outlet opening  24 . The inlet and the outlet openings are threaded in the usual manner for connecting a conduit to the inlet opening and another conduit to the outlet opening. 
     Referring to FIGS. 1 and 7, by-pass valve  10  is connected in a service system, which includes a gas supply conduit  26 , a meter conduit  28 , a gas meter  30 , and a second by-pass valve  32  for supplying gas to a customer service line  34 . Arrows  36  illustrate gas flow through a bypass conduit  38  connected to valves  10  and  32  to isolate meter  30  for service or replacement. Valves  10  and  32  are similar. The gas flows from the inlet side of valve  10  to the outlet side of valve  32 . 
     Referring to FIGS. 2 and 3, valve body  18  has a ball valve chamber  40  between inlet opening  22  and outlet opening  24 . A conventional ball valve  42  is slidably, rotatably mounted in the valve chamber for motion between a closed position, illustrated in FIG. 3, blocking gas flow from inlet opening  22  to outlet opening  24 , and an open position, illustrated in FIG. 6, in which the gas flows through a ball valve opening  44  from the inlet opening to the outlet opening. O-rings  46  and  48  provide a seal between the valve and the valve chamber. 
     A handle  50  mounted on a valve stem  52  attached to the ball valve, provides means for turning the ball valve between the open and closed positions. The operator has a four-sided shape for receiving a wrench (not shown) for turning the valve. 
     Referring to FIGS. 5 and 6, the valve body has an internal bypass passage  52  fluidly connected to passage  20 . The by-pass passage extends laterally from passage  20 , and then upwardly at  54  to an internally threaded by-pass port  56  (which opens on the same side of the body as handle  50  is disposed). By-pass plug  16  threadably mounted in by-pass port  56 . 
     Referring to FIG. 1, by-pass plug  16  has a hexagonal opening  58  for receiving an Allen wrench. Other types of security devices could be employed as well as other types of openings, such as a special Torx opening. The Allen wrench is turned in the clockwise direction with the plug to insert the plug to the FIG. 6 position, flush with the top edge of by-pass port  56 . The Allen wrench is turned in the counter clockwise direction to remove plug  16  from the by-pass port, for connecting by-pass conduit  38 . 
     Handle  50  has a locking solid tab wing  62  on valve stem  52 , which rotates with the ball valve element between its open and closed positions. 
     A security shutter valve  64  is threadably mounted in a shutter valve opening  66  in a boss  68 . Opening  66  extends laterally from through passage  20 . The shutter valve is basically a solid plug having an internal tool-receiving opening  70 . An O-ring seal  72  provides a gas tight seal between the shutter valve opening and the shutter valve. Shutter valve opening  70  has a special female configuration for mating with a tool (not shown) having a complementary male configuration. A security cap  74  and a washer  76  are mounted on the end of the shutter valve opening. 
     The shutter valve is movable between a closed position blocking gas flow through by-pass passage  52 , as viewed in FIG. 6, and an open position permitting gas to flow from supply conduit  26 , into one end of the valve body and out through bypass port  56 . 
     Locking wing  62  in the position of FIG. 6, overlaps the by-pass port and blocks removal of bypass plug  16 . In this position of the locking wing, ball valve  42  is open, permitting gas to flow from supply line conduit  26  to the meter conduit  28 . To isolate meter  30 , the user turns the locking wing about 45° from its position as viewed in FIG. 4, in the clockwise direction. He removes by-pass plug  16  and installs one end of by-pass conduit  38  in by-pass port  56 . He then removes security cap  74 , and turns security shutter valve from the fully closed position, illustrated in FIG. 6, to the fully open position, illustrated in FIG.  5 . The user then turns valve handle  50  to the FIG. 2 position, to close ball valve  42  and isolate the meter for service or replacement. Gas flow is then from supply conduit  26  through the by-pass passage in valve  10  and out through by-pass conduit  38 . 
     The process is repeated for valve  32 . Note that the by-pass part of valve  32  is in the downstream side of the valve. The gas flows through the by-pass passage of valve  32  to the customer service line. 
     To place the meter back in service, the user slowly turns the handle/operator in the counter clockwise direction to fluidly connect supply conduit  26  to meter conduit  28 . He turns the shutter valve to its fully closed position, illustrated in FIG.  6 . He then installs security cap  74 , removes by-pass conduit  38  from the by-pass port and reinstalls plug  16 . He then completely opens the ball valve to its normal functioning position as shown is FIG.  4 . He reverses this process to isolate the meter. 
     When valve  10  is in its fully closed position, opening  92  in the locking wing overlaps a similar opening  94  in a wing  96  that is fixed with respect to the body. He inserts key-operated locking device  12  by passing shackle  98  through both openings  92  and  94 , and then locking the shackle with respect to the body of device  12 . 
     This procedure prevents tampering with the valve in its closed position. 
     In some cases, by-pass conduit  38  need not be used. In such a structure, valve  10  is closed, and a tank of gas, not shown, can be connected to the by-pass port of closed valve  32 , to isolate meter  30 , while continuing gas flow to the customer service conduit  34 .