Cable routing in wastewater lift station

Information

  • Patent Grant
  • 6772782
  • Patent Number
    6,772,782
  • Date Filed
    Monday, November 3, 2003
    21 years ago
  • Date Issued
    Tuesday, August 10, 2004
    20 years ago
Abstract
A modular well for a wastewater lift station includes multiple well sections. Each of the well sections has at least one mating feature allowing it to be joined to at least one other well section and to form a liquid tight seal. The well is formed by vertically mating the well sections together. One of the well sections has an inlet opening, and the same or a different well section has at least one outlet opening.
Description




BACKGROUND




Wastewater lift stations, which lift wastewater from one elevation to a higher elevation to facilitate moving downstream by gravity, are generally known.




In a typical lift station assembly, an in-ground well receives wastewater, such as sewage, through an inlet in a side wall of the well. The wastewater accumulates within the well until it reaches a predetermined level, at which point a submersible pump or other wastewater moving device in the well is automatically triggered to begin evacuating wastewater through an outlet in the side wall located at an elevation above the inlet.




The pump continues operating until the level of accumulated wastewater in the well decreases to a second predetermined level. The elevation of the outlet may be sufficient to allow the evacuated wastewater to flow by gravity, e.g., via a sewer main to a municipal wastewater treatment plant.




Conventionally, most wastewater lift stations have been custom designed and engineered for a particular facility, with the lift station requiring extensive fitting, fabrication and assembly on site. Custom designs and any extended on-site activity require additional time and personnel with substantial experience and/or special certifications, both of which increase costs.




Conventional lift stations not designed according to a modular approach frequently include components, whether specially fabricated or off-the-shelf products from suppliers, that have not been used or used together in a lift station. Attempts to assemble these components on-site often reveal incompatibility and performance problems. Even a minor on-site problem can cause unpredictable and costly delays. Incompatibility problems that are not discovered initially require expensive service visits and may result in costly system failures.




SUMMARY




A modular, integrated wastewater lift station has components which are pre-configured to reduce on-site installation time and to avoid potential component incompatibility problems. Certain components are available in a selected, but finite range of sizes to suit a great majority of different applications that may be commonly encountered.




The well is constructed from pre-formed well sections, and includes a bottom well section, one or more intermediate well sections, and a top well section. The depth of the well can be set as desired by selecting an appropriate number of intermediate well sections, which are positioned on top of each other and on top of the bottom well section that has been placed at an appropriate elevation (e.g., at the bottom of an excavated hole). The top well section is mated with the top of the uppermost intermediate well section and covers the well.




The well sections are pre-fabricated at the factory to include some components and have features for receiving other components. Some of these features may, e.g., help to avoid the need to align and drill holes on-site to attach components.




Installation is simplified, as little on-site fabrication or changes to the basic design of the lift station is required. Installation can be completed more quickly and with more assurance, since there is less chance of encountering a problem or failing to fully configure any of the components.











BRIEF DESCRIPTION OF FIGURES





FIG. 1

is a vertical cross section of a lift station assembly, showing a front side of one implementation for a typical installation in an excavated hole.





FIG. 2

is a partial oblique view showing a lower end of a top cover well section of the lift station assembly of FIG.


1


.





FIG. 3

is an oblique view showing the two pump positions in a bottom sump well section of the lift station assembly of FIG.


1


.





FIG. 4

is partial oblique view of a top portion of the lift station assembly of FIG.


1


.





FIG. 5

is a top perspective view showing a utility vault suited for use with the lift station assembly of FIG.


1


.











DETAILED DESCRIPTION




A modular lift station assembly includes a well that receives and stores wastewater, a wastewater moving device operable to evacuate the wastewater within the well and a wastewater moving device control circuit that provides control signals to the wastewater moving device. In addition to wastewater, the lift station assembly can be used to evacuate storm water or in other applications where a collected body of liquid needs to be elevated against the force of gravity.




The well comprises multiple mating sections, including at least a bottom sump section and a top cover section, together with one or more intermediate sections positionable between the sump section and the cover section. When assembled, the well sections are sealingly engaged with each other and form the well.




The well has an inlet through which wastewater is received and at least one outlet through which wastewater is evacuated. When the well sections are assembled, the outlet(s) is at an elevation above the inlet. The inlet and outlet(s) may be formed in the same well section, or in different well sections, depending upon the geometry of the particular application.




The wastewater moving device, which may be, e.g., at least one submersible pump positioned in the well, is controlled to operate and evacuate accumulated wastewater from within the well upwardly and out through the outlet(s). In typical installations, two submersible pumps are used for redundancy (i.e., in the event that one pump fails or requires maintenance) and for increased pumping capacity (i.e., both pumps can be operated simultaneously in the event of a heavy load), although a single pump could also be used.




A valve vault that houses preassembed valves and connecting pipe sections for placement downstream of and connection to the outlet(s) of the lift station may also be provided.




Well




In a specific implementation, as shown in

FIG. 1

, a lift station assembly


10


has a generally in-ground wet well


12


formed of multiple modular well sections


14


,


16


,


18


and


20


that have been assembled together end-to-end with a gasket


48


between each adjacent pair of well sections. As illustrated, each of the well sections


14


,


16


,


18


and


20


has a generally circular outer periphery, such that the assembled well


12


has a generally circular cylindrical outer surface


22


.




The well section


14


, referred to herein as the bottom sump well section, has an outer surface


24


and a lower end


23




a


that forms a base of the well


12


. As illustrated in

FIGS. 1 and 3

, an external edge


26


of the lower end


23




a


extends laterally outward beyond the outer surface


24


.




The lower end


23




a


may be square as shown or rectangular. Under some conditions, e.g., in soil saturated with groundwater as frequently found in coastal locations, significant uplifting forces (F


U


) urging the wet well


12


upward are experienced. One way to reduce this effect is to provide a substantial surface area adjacent the bottom of the wet well


12


and against which the same forces can act in the opposite (i.e., downward) direction to counteract the uplifting forces (as shown by the arrows F


D


). In other words, the forces F


D


on the upper side of the lower end


23




a


between the outer surface


24


and the external edge


26


are substantially the same in magnitude as the forces F


U


on bottom surface, but the forces F


D


act in the opposite direction and thus counteract at least a portion of the uplifting forces F


U


. Although a circular lower end could be used, a square or rectangular lower end provides more counteracting surface area than a circular lower end having approximately the same major dimension from the standpoint of required storage or transportation space.





FIGS. 1 and 3

show an inner surface


28


of the bottom sump section


14


that defines an interior or sump


30


having a generally level bottom surface


32


, a sloping first side surface


34


extending upward from the bottom surface


32


, a generally vertical second side surface


36


extending upward from the first side surface


34


and a sloping third side surface


38


extending from the second side surface


36


to an upper end


23




b


. As illustrated in

FIG. 1

, the sump


30


has an inverted, generally frustoconical shape.




As best illustrated in

FIGS. 1 and 3

, the upper end


23




b


of the bottom sump section


14


is formed with an engagement feature, e.g., a peripheral two-level rim


40


, configured to engage a corresponding feature on an adjacent well section when assembled. The two-level rim


40


has a generally flat outer rim


42




a


at a first level, a sloping connecting surface


42




b


extending upward from the outer rim


42




a


and a generally flat inner rim


42




c


extending from the connecting surface


42




b


that forms part of the upper end


23




b.






As illustrated in

FIG. 1

, the lower intermediate well section


16


is a hollow cylinder having a bottom end


44




a


formed with a two-level lip


46


shaped to engage the two-level rim


40


. The gasket


48


is positioned between the two-level rim


40


and the two-level lip


46


to provide a fluid tight seal between the bottom sump well section


14


and the lower intermediate well section


16


in the assembled well


12


.




The gasket


48


is preferably made of rubber, but may be made of any material that is capable of withstanding contact with gases, liquids, and solid material that may reside within the well


12


. Possible gasket materials include, but are not limited to, rubber, Neoprene™, Teflon™, and Kevlar™.




The two-level lip


46


has a generally flat outer lip


50




a


at the bottom end


44




a


, a sloping connecting surface


50




b


extending upward from the outer lip


50




a


and a generally flat inner lip


50




c


extending from the connecting surface


50




b


at a level above the outer lip


50




a


. The lip


46


is dimensioned such that the inner lip


50




c


, the gasket


48


and the inner rim


42




c


form a fluid tight seal when the lower intermediate well section


16


is rested upon the bottom sump well section


14


.




As shown in

FIG. 1

, upper ends


44




b


and


52




b


of the lower intermediate well section


16


and upper intermediate well section


18


, respectively, each have a two-level rim similar to the rim


40


. Similarly, lower ends


52




a


and


54




a


of the upper intermediate well section


18


and the well section


20


, respectively, each have a two-level lip similar to the lip


46


.




As shown in

FIG. 1

, the lower intermediate section


16


has a side wall


56


in which an inlet opening


58


has been formed. The inlet opening


58


may be approximately circular as shown, or may be formed in any other suitable shape, and there may be multiple openings. In the illustrated implementation, the inlet opening


58


is formed sufficiently large to allow a wastewater inlet pipe


60


to be inserted through the inlet opening into the interior of the well


12


. (In certain applications, more than one inlet opening


58


may be required.)




The upper intermediate well section


18


, which is also a hollow cylinder, has a side wall


62


in which two outlet openings


64


have been formed, one of which can be seen in FIG.


1


. The second opening is usually formed at the same height, but may be formed at a different height if required. As in the case of the inlet opening


58


, the outlet openings


64


may be circular as shown, or may be formed in any other suitable shape. In the illustrated implementation, the outlet openings


64


are formed sufficiently large to receive respective wastewater outlet pipes


66


.




The inlet opening


58


and the outlet openings


64


may be formed, e.g., by a boring operation in each respective well section after it has been formed and cured. These openings, as well as the valve vault openings described below, are typically formed to be slightly larger than the respective outer diameters of the pipes received therein, with the remaining space surrounding the pipes being filled by a pipe boot or similar arrangement (e.g., a KOR-N-SEAL, which is a surrounding rubber seal expandable by turning a screw) to create a watertight connection. A representative pipe boot


65


is shown filling the space between the outlet opening


64


shown in FIG.


1


and an outlet pipe


65


.




In the illustrated example, the well


12


includes two intermediate well sections


16


,


18


. In other applications, there may be only one or more than two intermediate well sections. Also, the inlet opening(s)


58


and the outlet opening(s)


64


may be formed in a single well section, or in separate well sections. Further, there may be intermediate well sections formed without any inlet or outlet openings.




The well section


20


, referred to herein as the top cover well section, serves to cover the well


12


. The top cover well section


20


, which is a generally disk-shaped solid, has an access opening


67


formed therein to provide access to the well


12


. As illustrated in

FIGS. 1 and 5

, the access opening


67


may be generally rectangular. Components used to cover the access opening are described below.




The top cover well section


20


is also pre-formed with a lateral passage


68


. As illustrated in

FIG. 1

, the passage


68


connects a side opening


70


positioned at an outer side surface


72


and a bottom opening


74


in the lower end


54




a


adjacent the access opening


67


.




The well sections


14


,


16


,


18


and


20


are typically pre-cast of 4000 psi concrete. In typical implementations, reinforced concrete is used. Traffic load codes may require the use of reinforced concrete for at least the top cover well section


20


. Typically, at least the bottom sump well section


14


has a self-cleaning insert. In the illustrated implementation, the bottom well section has been cast with the insert in place so that the insert forms an integral part of the inner surface


28


. Optionally, the intermediate well sections


16


and


18


may also be fitted with similar liners, especially for use in warm and/or marine climates.




Depending upon the desired diameter of the wet well


12


, some of the sections described above may be formed as multiple components. For example, to maintain the weight of each section below a desired threshold, e.g., due to handling or transportation concerns, the bottom sump section


14


may be formed as separate upper and lower components (not shown). In such implementations, the upper and lower components may be formed to create a watertight joint as described above for the section-to-section connections.




For modularity, the well sections


14


,


16


,


18


and


20


are made available in standard diameters, e.g., 60, 72 and 84 inches. Typically, the bottom sump section


14


is formed to have a height of about 36 inches, whereas the intermediate well sections


16


and


18


are formed to have a height of about 60 inches. For the 84 inche diameter implementation the bottom sump


14


may include separate bottom and top components (about 26.75 inches and about 16.375 inches in height, respetively), which are each lower in weight than a single bottom sump section of this size, thus facilitating formation, storage, transportation and installation.




According to ASTM C 478-97, up to five intermediate well sections can be “stacked,” thereby providing a well of 25+feet in depth.




Inlet, Pump and Outlet




In a typical installation, called a duplex arrangement, two pumps


78


(one being shown in

FIG. 1

) are positioned in the well


12


generally within the sump


30


.




Suitable types of pump are the C-Pump series or the N-Pump series from ITT Flygt (headquartered in Stockholm, Sweden) in 3 hp to 23 hp sizes. The N-Pump series pumps are submersible pumps with a special self-cleaning impeller suited for reliably moving wastewater that may contain fibrous material.




An outlet side of each pump


78


is connected to the respective outlet pipe


66


at its lower end, e.g., at an elbow


82


. As illustrated in

FIG. 1

, an inlet side


79


is positioned downwardly to draw wastewater into the pump


78


from below. From the elbow


82


, the outlet pipes


66


lead upward and out of the well


12


through the respective outlet openings


64


. Each elbow


82


is rigidly attached to an elbow bracket


83


attached to the sump


30


.




In

FIG. 3

, the relative side-by-side positions of the two pumps


78


in the duplex arrangement can be seen. As also shown in

FIG. 3

, the elbows


82


can be pre-attached to the brackets


83


, which are attached with fasteners pre-formed in the bottom surface


32


. By accurately locating the fasteners and brackets


83


upon formation of the bottom sump section, proper alignment of the pump and pump rail is facilitated.




One or both of the pumps


78


may have a coupler


84


that allows it to be automatically engaged with and sealed against the elbow


82


upon being lowered into place by an operator O using a winch


85


as shown in FIG.


1


. In the same way, the pump


78


can also be disengaged for servicing or replacement. As illustrated in

FIG. 1

, a guide rail


86


may be positioned vertically within the well


12


and slidingly engaged with the pump


78


to assist in raising and lowering it.




Adjacent the inlet opening


58


, a deflector


87


may be attached to an inner surface


89


of the well


12


to shield the pump


78


from the direct flow of wastewater entering through the inlet opening


58


. As illustrated in

FIG. 1

, the deflector


87


, which is generally flat and rectangular in shape, is attached with fasteners arranged in two spaced vertical rows along the inner surface


89


. When viewed from above, the deflector


87


resembles a chord of the generally circular inner periphery of the well


12


.




A “guillotine” panel


90


, which can be raised or lowered by the operator O using the cable


92


, is positioned between the deflector


87


and the inner surface


89


. When the panel


90


is raised (shown partially raised in FIG.


1


), the inlet opening


58


and inlet pipe


60


can be viewed through an inspection opening


88


formed in the deflector


87


.




The deflector


87


and the panel


90


may be made of a plastic such as HDPE. The deflector


87


and the panel


90


prevent the pump


78


from cavitation damage and reduce off-gassing.




Control of the Pump




As illustrated in

FIG. 1

, a level sensor


94


is positioned within the well to assist in controlling operation of the pump


78


. One suitable level sensor


94


is the Liquid Level Sensing Probe available from Multitrode of Australia. The level sensor


94


may have indicia to allow the operator to confirm the level of wastewater within the well


12


visually.




The sensor


94


has a sensor cable


95


through which AC power is provided to the sensor


94


and sensor output signals indicative of the sensed wastewater level are transmitted from the sensor


94


. The sensor cable


95


is connected to the pump


78


and, optionally, to a remote location, such as a control panel (not shown).




The pump


78


has a power cable


98


through which AC power is supplied to operate the pump


78


. The power cable


98


may also be routed through the disconnect box


96


as illustrated in FIG.


1


. Power may be supplied from any suitable source, including an on-site electric generator.




In automatic operation, when the wastewater within the well


12


reaches an upper limit U as sensed by the level sensor


94


, one or both of the pumps


78


are selectively triggered to begin operation and evacuate the wastewater. The pump


78


continues to operate until the wastewater decreases below a lower level L as sensed by the level sensor


94


, at which point the pump


78


is controlled to cease operation. The level sensor


94


may have indicia to allow the operator to visually check the level of wastewater within the well


12


.




Disconnect Box and Passageway




The passageway


68


in the top cover well section


20


serves to vent gases from the well


12


and as a channel through which the sensor cable


95


and/or the power cable


98


can be routed to an above ground location, e.g., a disconnect box


96


. Because the passageway


68


is pre-formed, no on-site fabrication time is required. Routing of the cables is simplified if sharp corners are avoided. Gases in the passageway


68


are vented through openings in a steel grate


102


in the upper end


54




b


of the top cover well section.




The disconnect box


96


can be positioned on a stand


97


to provide convenient above-ground access to the sensor and pump electrical connections. In typical implementations, the disconnect box


96


is at least about 2 feet above ground, which permits standard electrical connections to be used, as opposed to the special explosion-proof connections that must be used within the well. In typical installations, the electrical connections are configured as plug-type connections, such as the quick-disconnect couplings


103


, that can be connected and disconnected by hand, and without requiring personnel with a special certification (e.g., an electrician).




As shown in

FIG. 1

, the stand


97


can be secured with fasteners (e.g., stainless steel bolts) that are pre-set in the top cover well section


20


. The stand


97


is shaped to allow the sensor cable


95


and the power cable


98


to be routed through it, and thus provides an improved appearance and increased protection against weather and the elements.




When the couplings


103


are disconnected, the cables


95


and


98


can be easily withdrawn through the passageway


68


, which is formed without sharp corners. The disconnect box


96


is fitted with a weather-proof and locking cover.




In typical installations, the disconnect box has a connection to a conventional control panel (not shown) through which level sensor signals and pump signals are sent for monitoring and/or control. The pumps signals may include a moisture sensor signal and/or a heat signal.




Access Opening




As illustrated in

FIGS. 1 and 4

, the access opening


67


in the top cover well section is sized to receive a cover member or cover member assembly. In the illustrated implementation, the access opening


67


receives grates


101




a


,


101




b


and respective overlying solid covers


100




a


,


100




b


. The grates


100




a


,


100




b


and the covers


1




a


,


100




b


are each hingedly attached to a side of the access opening


67


.




As best shown in

FIG. 4

, the grates


100




a


,


100




b


and covers


100




a


,


100




b


are each sized to cover about half of the access opening


67


. In this way, with fall protection for the operator in mind, only as much of the access opening


67


as is required to conduct a given task is exposed. For example, removal of a pump may require opening both covers


100




a


,


100




b


but only one of the grates


101




a


,


101




b


, as shown in FIG.


4


. Thus, the operator can stand on the grate


101




b


and/or set the removed pump on this grate to allow it to drain. During normal operation, the covers


100




a


,


100




b


and the gates


101




a


,


101




b


remain closed to seal the well


12


.




The access opening


67


can also be pre-formed with a guide rail receiving channel


104


(e.g., a nut rail) for the guide rail


86


and cable hangers


106


. The channel


104


allows the positions of the guide rail


86


and cable hangers


106


to be changed easily, in aligning the guide rail.




Valve Vault




As shown in

FIG. 5

, a preassembled utility vault


110


conveniently accompanies the lift station


10


to connect each outlet pipe


66


with downstream pipes, e.g., leading to a sewer main. Because the contents of the vault


110


are pre-assembled, on site installation requires only that three pipes be joined to the vault


110


.




The valve vault


110


is configured for a lift station having a duplex pump arrangement and two outlet pipes


66


. At one end of the valve vault


110


, one of the outlet pipes


66


is joined to a pipe section


120


, and the other of the outlet pipes is joined to a pipe section


122


. A pipe section


124


, which protrudes from the opposite end of the valve fault


110


, is joined to a downstream delivery pipe, e.g., a forced main.




Each of the pipe sections


120


,


122


is connected to a plug valve


126


(allowing the respective pump to be isolated in the event of a problem or for maintenance) and a check valve


127


(preventing downstream back pressure from causing a reverse flow from entering the well


12


through the outlet pipe


66


) before being joined together at a T-fitting leading to the pipe section


124


.




The vault


110


has a precast concrete shell and is formed with openings


114


and


118


for the pipe sections


120


,


122


and


124


. In specific implementations, the pipe sections


120


,


122


,


124


can be formed of ductile iron in 4″ or 6″ diameters.




The valve vault


110


may be provided with access doors (not shown) to prevent unauthorized access and intrusion by the elements. A drain may also be provided in a lower surface of the valve vault


110


.




Installation




The well sections


14


,


16


,


18


and


20


may each have indicia (not shown), such as vertical line or a cast notch painted with a visible color, on its outer surface to allow it to be aligned with adjacent well sections during installation. In certain embodiments, top and bottom portions of adjacent well sections may be fitted with a tongue and groove respectively (not shown), or some other keying system provided to facilitate alignment.




In embodiments with the inlet opening


58


and the outlet opening


64


formed in different well sections, the well section with the outlet opening


64


can be rotated relative to the well section with the inlet opening


58


, e.g., if necessary to improve the alignment of the openings with their respective pipes. Such an adjustment would not be possible with a conventional one-piece well.




The well sections and other components are transported to the site, typically by a conventional truck in a single delivery. If a suitable hole for the well


12


has been excavated, assembly of the lift station


10


proceeds with lowering of the bottom sump well section


14


into place, followed by the successive alignment and placement of each required intermediate well section. The pipes are routed as required, and then the top cover well section is placed. Thereafter, the other components, including the pump, pump rail, pump and level sensor cables, etc., are configured. The completed lift station


10


is usually configured to have the upper end


54




b


at a level of about 12 in. above the surrounding ground.




Having illustrated and described the principles of the invention in exemplary embodiments, it should be apparent to those skilled in the art that the illustrative embodiments can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of the invention can be applied, it should be understood that the illustrative embodiments are intended to teach these principles and are not intended to be a limitation on the scope of the invention. We therefore claim as our invention all that comes within the scope and spirit of the following claims and their equivalents.



Claims
  • 1. A method of configuring electrical connections for a wastewater lift station, comprising:providing an electrically-powered apparatus that is positioned within the wastewater lift station at a level below ground level; providing at least one electrical cable connected at a first end to the apparatus, the cable having a second end fitted with a quick-disconnect coupling; passing the second end of the cable through a cable routing passage to a terminal location, the terminal location being positioned outside the wastewater lift station and at a level spaced above ground level and having a mating quick-disconnect coupling; and connecting the quick disconnect coupling to a mating quick disconnect coupling connector.
  • 2. A cover assembly for a wastewater lift station, comprising:a cover having first and second opposing major surfaces and at least one outer side surface, the cover having a lift station access opening defined therein and extending through the major surfaces; and a preformed channel defined in the cover and extending from an inner end at the first major surface to an outer end at the at least one outer side surface, the channel having at least one vent opening extending from the channel to the second major surface.
  • 3. The cover assembly of claim 2, further comprising an upright member through which a cable from the channel can be routed, the upright member having a lower end positionable in alignment with the outer end of the channel and an opposite upper end positionable at a level above the second major surface of the cover.
  • 4. The cover assembly of claim 3, wherein the upright member has an interior cable routing area through which the cable can be routed.
  • 5. The cover assembly of claim 4, wherein the upright member has a locking access portion that can be unlocked to provide access to the cable routing area.
  • 6. The cover assembly of claim 3, further comprising an operator access box adapted for mounting to an upper end of the upright member, the operator access box housing a connector for connecting the cable to a source of AC power.
  • 7. The cover assembly of claim 6, wherein the operator access box is mounted at least 18 inches above ground level.
  • 8. A cover assembly for a wastewater lift station, comprising:a cover having opposing major surfaces and at least one outer side surface, the cover having a lift station access opening defined therein and extending through the major surfaces; and a channel defined in the cover and extending from an inner end that opens to an interior of the lift station to an outer end adjacent the outer side surface that opens to an exterior of the lift station, the channel providing for venting of gases through openings in a grate in one of the major surfaces of the cover.
  • 9. The cover assembly of claim 8, wherein the grate has an outer end positioned adjacent the outer side surface of the cover.
  • 10. The cover assembly of claim 9, further comprising an upright member through which one or more cables from the channel can be routed, the upright member having a lower end positionable in alignment with the outer end of the channel and over the outer end of the grate, the upright member having an access door that can be opened to allow the grate to be removed.
  • 11. The cover assembly of claim 9, wherein the grate has an inner end opposite the outer end, and wherein the inner end is engageable with a groove formed in the adjacent one of the major surfaces to secure the grate.
  • 12. The cover assembly of claim 8, wherein the inner end of the channel is positioned adjacent the lift station access opening.
  • 13. A cable routing construction for a wastewater lift station, the construction comprising:a channel extending generally laterally through an upper region of the lift station and at least partially comprising a preformed insert, the channel having an inner end opening to an interior of the lift station and an outer end opening to an exterior of the lift station, the channel defining a passage dimensioned to receive a cable and allowing gases to be vented from the interior.
  • 14. The construction of claim 13, wherein the channel has a top portion with vent openings extending from the passage to the exterior of the lift station.
  • 15. The construction of claim 13, wherein the channel is preformed in a top section of the lift station.
  • 16. The construction of claim 15, wherein the inner end of the channel that opens to the interior of the lift station is positioned at the lower surface of the of the top section, the outer end of the channel that opens to the exterior of the lift station is positioned at an outer side surface of the top section, and the channel extends from the inner end, bends toward the outer side surface and extends generally laterally to the outer end.
  • 17. The construction of claim 13, wherein the channel is dimensioned to allow movement through the channel of the cable and a connector fitted to an end of the cable.
CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of prior copending U.S. patent application Ser. No. 09/951,662, filed on Sep. 10, 2001, now U.S. Pat. No. 6,644,342, which is incorporated herein by reference.

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Continuations (1)
Number Date Country
Parent 09/951662 Sep 2001 US
Child 10/700807 US