Pumping system

Abstract

A pumping system for a wet well of a sewage system is disclosed which includes a submersible pump unit which can be lowered into and hoisted from an operating position in the well. The pump unit carries a detachable coupling by which the unit is coupled to a discharge conduit structure through which liquid is expelled from the wet well. The coupling includes interengaging parts which are detachable from the pump unit and the conduit structure for replacement. The coupling also carries an easily replaceable resilient lip seal element which engages the discharge conduit to prevent leakage between the pump unit and the discharge conduit.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to pumping systems and more particularly relates to pumping systems in which a pump unit is connected to a discharge conduit structure at a relatively inaccessible location by a coupling arrangement which enables the pump unit to be connected to and sealed with the discharge conduit structure.

2. The Prior Art

A number of prior art pump units have included submersible electric drive motors and are employed in excavations, wet wells in sewage systems, or similar relatively inaccessible locations where the pump unit is submerged in liquid and connected to a stationary pump liquid discharge receiving conduit structure. When sufficient liquid accumulated at the pump location, the pump unit was operated to pump liquid from the location via the discharge conduit structure.

A submersible pump unit normally included a pump housing having a tubular discharge section which was constructed to mate with an association discharge conduit. These constructions enabled a pump unit to be lowered to a submerged location, engaged with and supported by the discharge conduit, and operated from a remote electrical power supply to pump liquid from the location. When pump unit maintenance or repair was required, the pump unit was hoisted out of the liquid to a location where it was accessible to a serviceman.

A coupling arrangement formed by cooperating parts of the pump unit and the discharge conduit was usually employed to detachably secure the pump unit to the conduit structure without requiring a maintenance man to enter the liquid at the pump location. In some prior art proposals, the pump units were lowered along vertical guides which directed the coupling parts into engagement. The pump unit was usually lowered in a slightly tipped orientation to facilitate engagement of the coupling parts. As lowering continued, the pump unit tipped back to its operating orientation since at least part of the weight of the pump was supported by the discharge conduit via the coupling. When the pump unit was hoisted from its location it was tipped again to enable disengagement of the coupling parts.

In some other proposals when the pump was lowered it was wedged into engagement with the discharge conduit. The weight of the pump maintained the components tightly engaged when the pump was properly positioned. Hoisting the pump generally resulted in easy disengagement of the components.

These systems relied on the pump weight to provide sealing engagement between the pump units and the conduit structure. The establishment and maintenance of an effective seal at the juncture of the pump housing discharge section and the discharge conduit structure has been a long standing problem in the art. A number of prior art systems have employed metal-to-metal face seals. In these systems the pump housing discharge section terminated in a radical flange having an annular seal face. A flange on the conduit structure was provided with a mating annular seal face. The weight of the pump unit was used to force the sealing faces into engagement to prevent high pressure discharge liquid from leaking between the faces. In order to assure an effective seal, the sealing faces had to be highly finished surfaces and it was essential that the surfaces be accurately aligned.

There were a number of drawbacks to these proposals. The metal seal faces were susceptible to degradation and when this occurred, were quite difficult to repair. The liquids in which the pumps were submerged often contained suspended abrasive particles and the liquids themselves could be quite corrosive. Either or both of these factors contributed to seal failures since the sealing surfaces were exposed to the liquid and subject to corrosion and abrasion. When the seal failed, the seal faces had to be refinished necessitating removal of the pump unit and part of the discharge conduit from the system.

In order to avoid this problem, a proposal was made to position an O-ring type seal in a ring groove in the conduit flange. The O-ring seal had to be installed below the liquid level, was difficult to maintain in proper position during installation of the associated pump unit, and was likewise difficult to inspect and replace when it became worn.

Furthermore, the O-ring seals were circumferentially expanded by pumped liquid pressure and this caused seal wear as the seal slid along the associated sealing surfaces. To minimize abrasion of the O-rings, the associated flange surfaces were provided with relatively smooth finishes. Moreover, in some installations when the pump was not operating and was slightly misaligned with the discharge conduit, the relaxed O-ring became disengaged from its associated flange seal face. This allowed suspended matter in the liquid to become lodged between the O-ring and the seal face causing the seal to malfunction. The metal-to-metal seals suffered from the same problem.

The couplings were frequently formed by interengaging parts on the pump discharge and conduit flanges. This required the flanges to be provided with machined surfaces which were difficult to form during fabrication of the components. In order to maximize the durability of the couplings the pump housing and conduit were sometimes formed by high strength, corrosion resistant materials. Nevertheless, these parts were subject to eventual corrosion and wearing.

Motor driven pumps of the character referred to applied relatively large momentary starting torques to the couplings and seals while during operation of the pumps the couplings and seals were often subjected to vibratory forces. The application of these kinds of forces resulted in fretting wear and corrosion of the coupling parts which in turn caused progressively worsening misalignment which contributed to reduced seal life and efficiency.

Wearing and corrosion of the couplings eventually required replacement and/or repair of the pump housings and the associated discharge conduit sections. This was an expensive and time consuming procedure.

SUMMARY OF THE INVENTION

The present invention provides a new and improved pumping system wherein a pump unit and stationary discharge conduit structure are detachably coupled together to provide an efficient, long-lived seal between the pump unit and the discharge conduit, in which fretting wear and corrosion of the coupling parts is minimized and wherein repair and replacement of coupling and seal parts which do eventually become worn can be easily accomplished without requiring removal of piping from the discharge conduit structure.

In an illustrated embodiment of the invention, a pump unit is submerged in a wet well of a sewage system and is detachably connected to a stationary discharge conduit structure in the well. The pump unit is hoisted from and lowered into the well along fixed guide rails which guide the pump unit toward and away from the discharge conduit structure.

The pump unit includes a housing having a liquid inlet, a tubular discharge section, and a pumping device for drawing liquid from the well through the inlet and discharging the liquid through the discharge section. The pump is operated by a submersible electric motor integral with the housing.

One important feature of the invention resides in the construction of a coupling which is detachably connected to the pump housing discharge section and couples the pump unit to a flange of the discharge conduit structure. The new coupling provides an improved seal with the conduit flange to prevent leakage of liquid being pumped from the well through the conduit structure.

The coupling includes a coupling body which is detachably connected to the pump housing discharge section. The coupling body has a central flow opening aligned with the pump housing discharge opening so that liquid from the pump discharge section flow through the coupling body to the discharge conduit. A hook structure formed by a pair of widely spaced hook members which are integral with the coupling body projects above the coupling body towards the discharge conduit structure.

As the pump unit is lowered into its operating position in the well, the hook members engage a pump supporting element on the discharge conduit at locations above and on opposite sides of the conduit flange. The hook members couple the pump unit to the conduit with the weight of the pump unit at least partially borne by the hooks. The wide spacing of the hooks minimizes the torsional stresses applied to the hooks, the pump supporting element, and the seal when the pump motor is started or stopped.

The components of the coupling can be replaced separately from the pump unit and the discharge conduit when the coupling becomes worn or corroded. The pump supporting element is preferably constructed from a high strength corrosion resistant member which is separable from the discharge conduit. In the preferred embodiment of the invention the element is formed by a cylindrical rod which can be detached from the discharge conduit for replacement should it become worn or corroded. If the hooks become worn or corroded, the coupling body is removed from the pump unit and replaced. The coupling can thus be completely replaced without requiring additional machining of the pump unit and the associated discharge conduit section.

Another important feature of the invention is the provision of a circumferentially extending lip seal member carried by the coupling body for sealingly engaging the discharge conduit flange. The seal member has a body portion which is nested in and conforms to a dovetail groove which extends circumferentially about the discharge opening in the coupling body. A resiliently deformable circumferential sealing lip projects from the seal body portion away from the coupling body. The sealing lip is curved slightly inwardly towards the coupling body flow opening at its terminus. When the pump unit is coupled to the conduit structure the weight of the pump unit compresses the seal lip against the adjacent face of the discharge conduit flange. The lip is resiliently deflected towards the coupling body flow opening and hence when the pump operates, the discharge liquid pressure increases the sealing pressure applied by the seal lip to the conduit flange. Moreover, when pump operating vibrations occur which tend to change the alignment between the coupling body and the conduit flange, the seal lip tends to "roll" on the conduit flange which minimizes abrasion of the seal lip. This interaction between the seal lip and the conduit flange permits use of conduit flanges having "as cast" face finishes. Grinding or polishing is not required during fabrication.

The extent of projection of the lip from the coupling body assures that a seal is maintained with the conduit flange in all but the worst cases of misalignment of the pump unit and discharge conduit structure. When the pump is not operating the seal lip remains resiliently deflected by and engaged with the conduit flange so that foreign matter in the liquid cannot become lodged between the seal lip and the conduit flange.

Any time the pump unit is removed from the well, the coupling hooks and the seal can be inspected and, if damaged or worn, they can readily be replaced without requiring the pump housing discharge section to be repaired or machined. If the seal is worn it is easily removed from its supporting groove and replaced. The new seal is positively positioned in the groove and is not dislodged when the pump unit is repositioned for operation.

Other features and advantages of the invention will become apparent from the following detailed description of a preferred embodiment made with reference to the accompanying drawings which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of part of a pumping system embodying the invention with parts shown in alternate positions;

FIG. 2 is a top plan view of part of the system shown in FIG. 1 seen approximately from the plane indicated by the line 2--2 of FIG. 1;

FIG. 3 is a fragmentary side elevational view of part of the pumping system of FIG. 1 with portions shown in cross section;

FIG. 4 is a view seen approximately from the plane indicated by the line 4--4 of FIG. 3;

FIG. 5 is an enlarged elevational view of part of the apparatus of FIG. 2 seen approximately from the plane indicated by the line 5--5 of FIG. 2; and,

FIG. 6 is a side elevational view of the part shown in FIG. 5 seen approximately from the plane indicated by the line 6--6 of FIG. 5 with portions broken away and shown in cross section.

DESCRIPTION OF A PREFERRED EMBODIMENT

A pumping system 10 embodying the present invention is illustrated in FIG. 1 employed in a wet well 12 of a sewage system. The pumping system 10 includes a submersible pump unit 14, a pump discharge conduit structure 16, and a coupling 18 by which the pump unit 14 and conduit structure are detachably connected together in the wet well.

The wet well is formed by a liquid impervious tank 20 which is buried in the ground. A mounting plate 22 is attached to the base of the tank and the conduit structure is connected to the mounting plate. A pair of parallel guide rods 24, 26 are connected to the mounting plate 22 and extend upwardly through the well to an overhead access opening or manhole, not shown, at the top of the well. The pump unit can be removed from and replaced in the well via the manhole by raising and lowering the pump unit along the guide rails 24, 26.

The pump unit 14 is in its operating position when coupled to the discharge conduit structure as illustrated by broken lines in FIG. 1. The wet well accumulates liquid until a predetermined level is reached. The pump is then operated to pump liquid from the well via the conduit structure. When the liquid reaches a given low level the pump is stopped and the liquid permitted to accumulate again. Consequently the pump is normally at least partly submerged in the liquid when in its operating position. When pump maintenance is required, the pump is hoisted from the well to a location at which the pump is conveniently accessible to a maintenance man.

The discharge conduit structure 16 is built into the well 12 and comprises an anchor section 30 attached to the mounting plate 22 for partially supporting the pump unit and pipe section 32a-32e. As illustrated in FIGS. 1, 3 and 4, as the anchor section 30 is formed by a cast support body 34 having a lower base plate 36 connected to the mounting plate 22 and a pump discharge receiving elbow 38 which is integrally formed with the body 36 at its upper end. The discharge elbow 38 includes a vertically extending inlet flange 40 which faces the pump unit 14 and a generally horizontally extending circular outlet flange 42 to which the pipe section 32a is attached. The pipe sections 32a-32c extend upwardly from the elbow in the well while the pipe section 32e, only part of which is illustrated, extends horizontally from the well through an opening in the side wall. The pipe sections 32c and 32e are connected by a 90.degree. elbow section 32d at a location spaced substantially above the bottom of the well.

The inlet flange 40 of the discharge elbow 38 includes a generally circularly curved lower flange portion 44 and a thickened flange portion 46 which extends transversely across the upper side of flange portion 44. The flange 40 defines a planar front sealing face 48 which is engaged by the coupling 18 when the pump unit is in its operating position to prevent leakage of pump discharge liquid along the sealing face 48.

The Pump Unit.

Referring to FIGS. 1 and 2, the pump unit 14 is preferably an electric motor driven centrifugal pump which includes a cast, generally cylindrical pump housing 50 having a generally circular base 52 defining an inlet port 54, and a tubular projecting discharge section 55 which terminates in a mounting flange 56 surrounding a discharge port 58. A rotatable impeller 60 is disposed within the pump housing 50 for drawing liquid from the well via the inlet port 54 and discharging the liquid into the discharge conduit structure 16 via the discharge port 58. The impeller 60 is driven by a submersible electric impeller driving motor assembly 62 which is attached to the upper side of the housing 50. The drive motor is connected to the impeller by a vertically extending drive shaft, which is not illustrated, and the electric motor itself is energizable from a remote electrical power supply via a power cable 63 which extends upwardly through the wet well. Operation of the motor assembly 62 can be controlled in any suitable or conventional manner, for example by a liquid level sensing control, not illustrated.

The pump unit 14 requires inspection and maintenance from time to time and when maintenance is required the pump unit is hoisted from its operating position to a location where the pump unit is accessible to the maintenance man without requiring the maintenance man to enter the well. After maintenance is completed the pump unit 14 is again lowered into well to its operating position. The pump is moved into and from the well along the guide rods 24, 26. Vertical guide plates 64, 66 are connected to diametrically opposed sides of the pump housing 50 and each guide plate carries pairs of laterally projecting guide fingers 68, 70 at its upper and lower ends, respectively. The guide fingers are spaced apart a sufficient distance so that the associated guide rod extends loosely between the guide fingers of each pair. The guide finger spacing enables the pump unit 14 to tip slightly relative to the guide rods as the pump is raised from or lowered into the well.

In the preferred and illustrated embodiment of the invention a hoisting cable 72 is attached to the pump unit 14 by a cable eye 74 which is fixed to the motor assembly 62 at a location beyond the pump unit center of gravity from the anchor section 30. The upper end of the cable is connected to a winch or other suitable lifting mechanism. When the pump unit is suspended by the cable 72 it tips slightly to the orientation which is shown in full lines in FIG. 1 due to the location of the cable eye 74. Tipping of the pump unit when suspended by the cable facilitates engagement and disengagement of the coupling 18.

The Coupling

The coupling 18 interconnects the pump unit 14 to the discharge elbow 38 as the pump unit is lowered to its operating position and also provides a highly efficient seal with the discharge elbow seal face 48. Referring now to FIGS. 3-6 the coupling 18 comprises a coupling body 80 which is connected to the pump discharge flange 56, hook structure 82 integral with and projecting from the coupling body towards the discharge elbow 38, a pump supporting element 84 connected to the discharge elbow 38 for coupling engagement by the hook structure as the pump unit is lowered, and a seal construction 86 for preventing leakage of pumped liquid between the coupling body 80 and the discharge elbow seal face 48.

The coupling body 80 is formed by a generally "D" shaped planar plate-like member consisting of a high strength corrosion resistant material and is detachably connected to the pump discharge flange 56 by screws 90 which extend through openings in the pump discharge flange and into tapped holes 92 in the body 80. A secondary sealing gasket 94 is compressed between the body 80 and the sealing flange 56 when the screws 90 are tightened. The coupling body 80 defines a central flow opening 96 aligned with and having the same diametrical size and shape as the pump discharge port 58. Thus when the body 80 is connected to the pump discharge flange 56 liquid from the pump discharge port 58 flows unrestrictedly through the coupling body 80 and is prevented from leaking along the face of the flange 56 by the gasket 94.

Referring now to FIGS. 3, 5 and 6, the hook structure 82 is formed by a pair of widely spaced parallel hook members 100, 102 which are integral with the coupling body 80. The hook members project from opposite sides of the body 80 and extend upwardly and away from the body towards the discharge elbow flange 40. The hook members define downwardly facing circularly curved bight surfaces 104 having their centers of curvature located on a common horizontal axis. The downwardly projecting hook tip portion 106 of each hook member includes a bearing face 108 extending tangentially from the bight surface 104 generally parallel to the plane of the body 80. A cam surface 110 extends tangentially from the bight surface 104 toward the body 80 at a small angle with respect to the plane of the body 80 to provide for guiding the pump supporting element 84 onto the bight surface 104 when the pump unit is being coupled to the discharge elbow.

The hooks 100, 102 engage and seat on the pump supporting element 84 so that the pump unit can pivot relative to the discharge elbow 38 into its operating position. The pump supporting element 84 is preferably formed by a cylindrical rod which is disposed in a conforming horizontal bore hole 114 extending through the elbow flange portion 46 generally parallel to the plane of the seal face 48. The rod 84 is constructed of a high strength corrosion resistant material and is positioned and maintained in the bore hole 114 by a set screw 116 (see FIGS. 3 and 4).

Opposite end portions 118 of the rod 84 extend laterally beyond the discharge elbow flange 40 and these end portions are engaged by the respective hook members 100, 102. The rod has the same radius of curvature as the hook bight surfaces 104 so that the rod seats against the bight surfaces 104 when the pump unit and discharge elbow are coupled, yet the pump unit can pivot relative to the rod while the hook members and supporting rod remain in coupling engagement.

The wide spacing of the hook members 100, 102 tends to reduce the level of stresses imposed on the coupling due to motor starting torque loadings and vibratory forces which arise during operation of the pump. The reduction of these stresses results in reduced fretting wear of the engaged coupling parts and tends to increase the effective life of both the engaged coupling parts and the seal construction.

As the pump unit 14 is lowered to its operating position from the position illusutrated in full lines in FIG. 1, the hook members 100, 102 engage the respective end portions 118 of the rod 84 along the cam surface portions 110. The end portions of the rod are thus guided to the bight surfaces 104. The cam surface portions 110 also draw the uppermost portion of the coupling body toward the flange seal face 48 to assure engagement of the uppermost part of the seal construction 86 with the face 48. As the pump unit continues to be lowered, the pump unit and coupling body 80 rotate relative to the rod 84 to move the coupling body 80 into confronting relationship with the discharge elbow seal face 48. The weight of the pump unit 14, acting about the axis of the rod 84, urges the seal construction 86 into sealing engagement with the seal face 48. The hook faces 108 prevent the pump unit 14 from moving away from the face 48 when the pump is in its operating position.

The anchor section 30, via the coupling 18, supports at least part of the weight of the pump unit 14 and utilizes the weight of the pump to establish a positive seal between the discharge elbow flange 40 and the coupling body 80. In some installations, the pump unit 14 can weigh more than 1,000 pounds and in such installations, in order to reduce the stress applied to the coupling 18 and the anchor unit 38, a projecting leg (indicated by the reference character 120 in FIG. 1) is provided on the pump housing 50 for engagement with the base plate 22 when the pump is at its desired operating position. Smaller pumping units can be supported entirely by the coupling 18 and the anchor unit 30 and such units need not be provided with a support leg.

The seal construction 86 is best shown in FIGS. 3 and 6 and includes a generally annular resilient, soft rubber or plastic seal member 130 extending about the flow opening 96 in the coupling body 80 and bearing against the sealing face 48 on the discharge elbow flange 40. The seal member 130 includes an annular body portion 132 which is nested in and conformed to a circular, generally undercut or dovetail groove 134 formed in the coupling body 80 about the flow opening. A resiliently deformable annular lip portion 136 extends from the groove 134 towards the face 48. The lip portion curves radially inwardly proceeding towards its projecting edge 138 when in its relaxed condition (as illustrated in FIG. 6).

As the coupling body 80 pivots with the pump unit 14 towards the seal face 48, the lip portion 136 of the seal member is engaged by the seal face 48 and is both compressed and resiliently deflected radially inwardly to its configuration illustrated in FIG. 3. With the lip portion resiliently deformed in this fashion the pressure of the pumped discharge liquid passing from the pump discharge port 58 through the discharge elbow 36 acts on the lip portion to urge it into tighter sealing engagement with the flange seal face 48. When the pump is not operating the lip portion remains tightly engaged with the face 48 due to the resiliency of the lip portion.

The construction of the seal member 130 and the groove 134 are such that abrasion of the seal member is minimized. As the seal lip portion is pivoted into engagement with the seal face 48 it is deformed by more or less "rolling" engagement with the seal face 48. When the pump is operated, the pressure of pumped discharge liquid passing from the discharge port 58 through the elbow 38 acts to radially expand the seal element, but the radially outer side of the groove 134 tends to support the sealing lip against radially outward sliding or extrusion along the seal face 48. Moreover, when pump operating vibrations are transmitted to the seal member the lip portion has sufficient resiliency, even when compressed to the condition illustrated in FIG. 3, to resiliently flex with the vibrations so that the contacting surfaces of the flange 48 and the seal lip portion do not slide relative to each other appreciably. The amount of sliding of the seal element relative to the seal face 48 is thus minimized and abrasion of the seal member 130 is substantially avoided.

It has been found that a seal member constructed in accordance with the present invention can be utilized over long periods against a sealing flange face 48 having an "as cast" surface finish without noticeable abrasion of the seal member. This eliminates the necessity of grinding or polishing the seal face 48 during fabrication of the elbow 38.

Because the seal body 132 is conformed with the groove 134 the seal member is positively supported by the coupling body 80. Hence the seal element can be inspected for damage each time the pump unit 14 is removed from a well 12 without requiring the maintenance man to enter the well in order to inspect the seal. If the seal element becomes worn it is readily replaced and is positively positioned during installation of the pump unit.

Parts of the coupling 18 will inevitably become worn or corroded after the pump unit 14 has been in service for a period of time. When this occurs the alignment between the coupling body 80 and the discharge elbow 38 will be adversely effected in that the coupling body 80 may tend to move away from the seal face 48, particularly adjacent the hook structure. When this occurs the seal between the flange face 48 and the seal member 130 is maintained intact because the tip portion 136 tends to return toward its relaxed condition thus remaining resiliently engaged against the seal face 48. The sealing relationship is lost only in cases of severe wearing and misalignment of the coupling and discharge conduit.

When wearing or corrosion of the hook members 100, 102 or the rod 84 becomes pronounced, the entire coupling 18, or parts of it, can be replaced without requiring machining of the pump housing 50 or the anchor section 30. The coupling is replaced merely by unscrewing the coupling body 80 from the pump discharge flange 56 and replacing it. This is accomplished without requiring a maintenance man to enter the well. The rod 84 is replaceable by loosening the set screw 116 and replacing the rod. This does require a maintenance man to enter the well but does not require removal or loosening of any of the pipe sections in the discharge conduit structure.

Another advantage of the coupling 18 resides in the fact that the coupling itself can be formed of high strength corrosion resistant materials while the pump housing 50 and anchor section 30 can be cast materials which do not have or require all of the characteristics of the coupling material. Use of the coupling 18 thus effectively increases the useful life of the anchor section and pump housing while enabling their fabrication from readily available cast materials which need not be extensively machined to permit coupling and sealing functions.

While a single embodiment of the invention has been illustrated and described, the invention is not to be considered limited to the precise construction shown. Various adaptations, modifications and uses of the invention may occur to those having ordinary skill in the art to which the invention pertains and it is the intention to cover all such adaptations, modifications and uses which come within the spirit and scope of the appended claims.

Claims

We claim:

1. A pumping system comprising:

a. a submersible pump having an inlet and an outlet,

b. discharge conduit structure having a seal face,

c. a coupling body having first and second end faces and a flow passage ported on said faces,

d. means detachably connecting said coupling body to said pump so that said first end face is sealed against said pump with said flow passage communicating with said outlet,

e. guide means mounting said pump for vertical movement between an operating position in which said flow passage communicates with said discharge conduit structure and another position in which said pump is vertically spaced above said discharge conduit structure,

f. resilient seal means mounted on said second end face of said coupling body around said flow passage,

g. said pump being arranged on said guide means so that said second face of said coupling body is tilted down and away with respect to said seal face of said discharge conduit structure during movement of said pump along said guide means and so that said pump is rotatable to bring said seal means into sealing engagement with said seal face in said operating position,

h. hook structure on said coupling body extending toward said discharge conduit structure, and

i. hook supporting means carried by said discharge conduit structure in position to be engaged by said hook structure when said pump is lowered to said operating position, whereby said pump is clamped to said discharge conduit structure.

2. A pumping system as claimed in claim 1 in which said hook structure comprises a pair of laterally spaced hooks, each having a bearing surface substantially parallel to said second end face of said coupling body and engageable with hook supporting means to hold said second end face against said seal face of said discharge conduit structure.

3. A pumping system as claimed in claim 1 in which said hook supporting means comprises a rod.

4. The system as claimed in claim 1 wherein said conduit structure includes a flange defining said seal face, said supporting means includes portions extending generally parallel to the plane of said seal face and projecting from said conduit structure on opposite sides of said flange, said hook structure comprises first and second hook elements projecting from said coupling body, said hook elements each defining a bight engageable with a respective portion of said hook supporting means.

5. A pumping system as claimed in claim 1 in which said second end face of said coupling body includes a groove extending around the port of said flow passage and in which said resilient seal means comprises a seal element seated in said groove, said seal element having a resiliently deflectible sealing lip projecting from said second end face toward said seal face.

6. The system claimed in claim 5, wherein said groove has a generally dovetail shaped cross section and said seal element has a body section nesting in and conforming to said groove.

7. A pumping system comprising:

a. a pump having an inlet and an outlet,

b. a discharge conduit member having a terminating flange which defines a seal face,

c. rod means releasably secured to said conduit member, said rod means having laterally projecting portions beyond said terminating flange,

d. a coupling body having a pair of end faces and a flow passage ported on said faces,

e. means releasably securing said coupling body to said pump so that one end face is sealed to said pump and the other end face is positioned to mate with said seal face,

f. said other end face including a groove around the port of said flow passage,

g. a resilient seal element seated in said groove, said element having a resiliently deflectible sealing lip projecting from said other end face and engageable with said seal face,

h. fixed vertical guide means mounting said pump for movement between an operating position in which said other end face is sealed against said seal face with said flow passage in communication with said discharge conduit member and another position in which said pump is spaced above said conduit member,

i. said pump being arranged on said guide means so that said other end face of said coupling body is tilted down and away with respect to said seal face of said discharge conduit member during movement of said pump along said guide means and so that said pump is rotatable to bring said seal element into sealing engagement with said seal face in said operating position, and

j. a pair of laterally spaced hooks on said coupling body projecting toward said conduit member and engageable with projecting portions of said rod means in said operating position to clamp said pump to said discharge conduit member.

8. A pumping system as claimed in claim 7 in which said pump is mounted so that its center of gravity is aligned with said guide members, and hoisting means connected to said pump at a location offset from said center of gravity.

9. A pumping system as claimed in claim 7 in which said resiliently deflectible sealing lip projects away from said coupling body and circumferentially inwardly with respect to said flow passage, and in which said groove has a generally dovetail cross-section, said seal element having a body portion nested in and conforming to said groove.

10. The pumping system as claimed in claim 7 wherein each of said hooks comprises a bight surface for engaging said rod means, a cam surface merging with said bight surface and facing away from said coupling body, and a third surface facing said coupling body and merging with said bight surface, said cam surface being effective to guide said rod means to said bight surface during coupling and enable said seal element to engage said seal face of discharge conduit member, said third hook surface being parallel to said other end face of said coupling body and bearing on said rod means after coupling to prevent said pump from moving away from said discharge conduit member.