FOR PUMP PERFORMANCE CHARACTERISTICS CONTROL

BACKGROUND OF THE INVENTION

1 . Field of the Invention

This application relates to a pump or rotary device; and more particularly to a discharge casing of a pump or rotary device.

2. Brief Description of Related Art

The current standard for venturi casings is to drill and ream a discharge passageway due to low specific speed pumps' sensitivity to passage quality. A higher quality passage can be created by machining rather than using an as-cast surface. It is also known to cross drill a bypass from the discharge to the casing annulus which provides an enhanced curved shape. The bypass also improves the curve stability as well.

However, classic venturi designs are difficult to manufacture due to long drilling with relatively small drill bits. This creates a lot of machining deviation that greatly effects pump performance and first pass yield. This machining deviation is largely due to the pump's design rather than manufacturing issues causing an additional rework to achieve a required performance. Traditional venturi designs also limit a casing to having one throat size without requiring a remachine or a new casing (if going to a smaller throat size). Traditional venturi throats will experience wear over time and cause the effective throat area to increase. Significant wear can lead to performance changes which can necessitate costly casing rework or replacement.

In view of this, there is a need in the industry for a better way to configure a discharge passageway with a Venturi implementation. SUMMARY OF THE INVENTION

In summary, the difficulties of manufacturing classic venturi designs are solved with a new and unique discharge casing insert according to the present invention, e.g., that allows for larger bores to be drilled into the discharge and utilizing a discharge casing insert to control the minimum throat area required for proper performance characteristics of the pump. The larger discharge bore reduces pipe losses and also minimizes potential manufacturing defects often associated with small bits at long drill depths. The design of the new and unique discharge casing insert keeps tighter tolerance portions contained within it and allows for looser tolerance in the casing machining processes. Since the new discharge casing insert may be interchangeable, it also allows for throat changes in the aftermarket by simply replacing the discharge casing insert being used with one of a different throat area, thus allowing customers to change pump performance characteristics in the field. The new discharge casing insert also allows for a customer to easily change the pump's performance in the case of a worn out throat area. Being interchangeable, the new discharge casing insert can also be made in different materials than the rest of the casing for improved material properties or wear resistance.

In effect, the new discharge casing insert according to the present invention works by containing the pump throat area within the discharge casing insert itself rather than the traditional drilled-style found in current venturi casings. By containing the throat in the insert, the new discharge casing insert greatly improves the manufacturability of the pump and gives more customer control over pump performance. By way of example, and consistent with that set forth above, the discharge case may be manufactured (i.e., drilled) with a larger-sized bore to receive the discharge casing insert that is configured to control the throat area for providing certain performance characteristics of the pump. In the aftermarket, the customer may remove the discharge casing insert and replace it with a different discharge casing insert that is received in the same larger bore, but has a different throat area to change the performance characteristics of the pump. In addition, the number of casing configurations is also reduced allowing for stocking of machined casings and the customizing of the discharge performance of a customer's order by only changing the geometry of the new discharge casing insert. This also gives a customer the option to re-rate their pump in the field by purchasing a new discharge casing insert, allowing their installations to be more dynamic. As the discharge casing wears with use, a standard drilled venturi casing would need to be replaced to restore lost performance, but the new discharge casing insert according to the present invention allows for easy performance restoration thus increasing the useful life of the casing.

The new discharge casing insert contains geometry which defines the throat area, or flow restriction point, of the pump. This geometry is inserted into the larger bore discharge drilling and acts as the choke point for the discharge of effluent from the pump.

By way of example, discharge casing inserts can either have built in sealing mechanisms to seal the casing or require additional hardware to seal them into the casing. Some embodiments disclosed herein provide a new discharge casing insert which contains a built in flange for assembly to the discharge casing, while other embodiments disclosed herein provide a new discharge casing insert which uses an external sealing and assembly feature to seal it within the discharge casing. The present invention is intended to cover the use of any discharge casing insert which may be placed in the discharge flow path to alter pump performance by means of obstruction in flow or reduced cross section.

By way of one example, the design of the new discharge casing insert may include, take the form of, or use a variable sized or shaped pin to restrict the flow and create the proper "throat area" and performance characteristics. The geometry of the new discharge casing insert may be round or have other geometry which effects pump performance.

Other discharge casing insert designs may include inserts having an angled inlet and exit geometry with a drilled throat geometry. This design may also contain a drill through to tap into the bypass drilling of the pump for improved performance in high recirculation conditions.

In effect, the new discharge casing insert provides a better way to configure a discharge passageway with a Venturi implementation, and is an important contribution to the state of the art and the pump or rotary device industry as a whole.

The Apparatus

According to some embodiments, the present invention may take the form of apparatus, e.g., including a pump or rotary device, featuring a discharge casing in combination with a new and unique discharge casing insert. The discharge casing may be configured with a discharge flow pathway for providing a flow of effluent being pumped and discharged, the discharge flow pathway having a discharge flow pathway wall, the discharge casing also configured with a discharge casing borehole that passes from an outer surface of the discharge casing through the discharge flow pathway wall. The discharge casing insert may include a discharge casing Venturi plug portion to be received in the discharge casing borehole and arranged in the discharge flow pathway, the discharge casing Venturi plug portion configured with a restricted discharge flow pathway for providing a partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged.

The apparatus may include one or more of the following features:

The discharge flow pathway has a cross-section, and the discharge casing Venturi plug portion may be configured with a corresponding discharge flow pathway, one part or section of which has a corresponding cross-section that is substantially the same as the cross-section of the discharge flow pathway, and another part or section of which has a reduced cross-section that is less than the cross-section of the discharge flow pathway.

Dowel Pin Arrangements

Some embodiments may include the discharge casing Venturi plug portion having a dowel pin configured therein, e.g., for providing the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged from the discharge casing.

By way of example, the discharge casing Venturi plug portion may be configured with a dowel pin bore; and the discharge casing Venturi plug portion may include a dowel pin configured to be received in the dowel pin bore, so as to configure the restricted discharge flow pathway to provide the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and

discharged.

The dowel pin may be arranged in the dowel pin bore, so as to restrict some part of section of the corresponding discharge flow pathway and provide the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged.

In some embodiments, the dowel pin may be configured as a rod (e.g., a solid rod) having a shaft with a reduced diameter that is less than the cross-section of the discharge flow pathway, so as to restrict some part or section of the corresponding discharge flow pathway and provide the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged.

In other embodiments, the dowel pin may be configured with an orifice having a reduced cross-section that is less than the cross-section of the discharge flow pathway, so as to restrict some part or section of the corresponding discharge flow pathway and provide the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged.

The discharge casing insert may include a set of dowel pins, where each dowel pin may be configured to be received in the dowel pin bore, and where each dowel pin may also be configured to provide a different-sized partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and

discharged, so that performance of the pump may be adjusted based upon the selection of which dowel pin is used from the set of dowel pins so as to provide a desired throat area.

In some embodiments, each dowel pin may be configured with a respective shaft having a different diameter, where a dowel pin having a larger diameter causes a larger partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged, and where a corresponding dowel pin having a smaller diameter causes a smaller partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. Alternatively, each dowel pin may be configured with a respective orifice having a respective diameter that causes a respective partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. By way of example, the set of dowel pins may include a first dowel pin having a first orifice with a first diameter that causes a first partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged, and may also include a second dowel pin having a second orifice with a second diameter that is different from the first diameter and that causes a different-sized partial obstruction than the first partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. In effect, the partial obstruction forms a restricted discharge flow pathway that may be configured with a geometry and/or variables shapes, e.g., that may include, but not be limited to, either a round geometry or shape, a triangular geometry or shape, a rectangular geometry or shape, a square geometry or shaped, or an oval geometry or shape.

Integrally Formed Inlet Arrangements

Some embodiment may include the discharge casing Venturi plug portion configured with an inlet/opening that may be drilled or integrally formed therein, e.g., for providing the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged from the discharge casing.

By way of example, the inlet/opening may be configured or formed having a reduced cross-section that is less than the cross-section of the discharge flow pathway, so as to restrict some part or section of the corresponding discharge flow pathway and provide the partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. The orifice may be configured, shaped or formed with an inlet portion having a reduced cross-section that is less than the cross-section of the discharge flow pathway, and an expanding conical portion having a cross-section that is less than, the same, or larger than the cross-section of the discharge flow pathway.

The orifice may also be configured, shaped or formed with an expanding portion that may have a larger cross-section than the cross-section of the discharge flow pathway, an inlet portion having a reduced cross-section that is less than the cross-section of the discharge flow pathway, and also an expanding conical portion having a cross-section that is less than, the same, or larger than the cross-section of the discharge flow pathway.

The apparatus may include a set of discharge casing inserts, where each discharge casing insert has a respective discharge casing Venturi plug portion configured to be received in the dowel pin bore, and where each discharge casing Venturi plug portion may also be configured to provide a different-sized partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged, so that performance of the pump may be adjusted based upon the selection of which discharge casing Venturi plug portion is used from the set so as to provide a desired throat area.

In some embodiments, each discharge casing Venturi plug portion may be configured with a respective orifice having a respective diameter that causes a respective partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. For example, the set of discharge casing inserts may include a first discharge casing Venturi plug portion configured with a first diameter orifice having a first diameter that causes a first partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged, and may also include a second discharge casing Venturi plug portion configured with a second orifice with a second diameter that is different from the first diameter and that causes a different-sized partial obstruction than the first partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged. Consistent with that set forth above, the partial obstruction forms a restricted discharge flow pathway that may be configured with a geometry and/or variables shapes, e.g., that may include, but not be limited to, either a round geometry or shape, a triangular geometry or shape, a rectangular geometry or shape, a square geometry or shaped, or an oval geometry or shape.

BRIEF DESCRIPTION OF THE DRAWING

The drawing, not necessarily drawn to scale, includes the following Figures: Figure 1 includes Figures 1 A and 1 B, where Figure 1 A is a diagram of a discharge casing having a discharge casing borehole, and Figure 1 B is a diagram of a discharge casing having a discharge casing insert arranged in the discharge casing borehole shown in Figure 1 A, according to some embodiments of the present invention.

Figure 2 includes Figures 2A, 2B, 2C and 2D, where Figure 2A is a diagram of a side view of a discharge casing insert looking through the discharge flow pathway of the discharge casing insert; Figure 2B is a cross-sectional view along lines A-A of the discharge casing insert shown in Figure 2A; Figure 2C is a diagram of a pin dowel that forms part of the discharge casing insert shown in Figures 2A and 2B; and Figure 2D is a diagram of a bottom view of the discharge casing insert shown in Figures 2A and 2B, according to some embodiments of the present invention. Figure 3 includes Figures 3A, 3B, 3C and 3D, where Figure 3A is a diagram of a side view of a discharge casing insert looking through the discharge flow pathway of the discharge casing insert; Figure 3B is a cross-sectional view along lines A-A of the discharge casing insert shown in Figure 3A; Figure 3C is a diagram of a pin dowel that forms part of the discharge casing insert shown in Figures 3A and 3B; and Figure 3D is a diagram of a top view of the discharge casing insert shown in Figures 3A and 3B.

Figure 4 includes Figures 4A, 4B and 4C, where Figure 4A is a diagram of a side view of a discharge casing insert; Figure 4B is a cross-sectional view along lines A-A of the discharge casing insert shown in Figure 4A; and Figure 4C is a diagram of a top view of the discharge casing insert shown in Figures 4A and 4B.

Figure 5 includes Figures 5A, 5B and 5C, where Figure 5A is a diagram of a side view of a discharge casing insert; Figure 5B is a cross-sectional view along lines A-A of the discharge casing insert shown in Figure 5A; and Figure 5C is a diagram of a top view of the discharge casing insert shown in Figures 5A and 5B.

Figure 6 includes Figures 6A and 6B, where Figure 6A is graph of a data comparison of sample test data for two venturi sizes, one for a Venturi insert casing, and the other for a standard drilled casing, based upon total head (Ft), flow (GPM) and efficiency (%); and where Figure 6B is also graph of a data comparison of sample test data for two venturi sizes, one for a Venturi insert casing, and the other for a standard drilled casing, based upon total head (Ft), flow (GPM) and efficiency (%) ^■

Not every reference numeral is included in every Figure, e.g., so as to reduce clutter in the drawing as a whole. DETAILED DESCRIPTION OF THE INVENTION

Figure 1 : The Basic Apparatus 10

According to some embodiments, the present invention may take the form of apparatus, e.g., including a pump or rotary device, having a discharge casing part shown in Figures 1 A and 1 B and generally indicated as 10, that features a discharge casing 12 in combination with a discharge casing insert 14 (see Figure 1 B, 2 and 3), 140 (see Figures 4 and 5). The discharge casing 12 may include a discharge casing annulus 12a. Figure 1 A shows the discharge casing 12 without the discharge casing insert 14, while Figure 1 B shows the discharge casing 12 with the discharge casing insert 14 configured therein.

The discharge casing 12 may be configured with a discharge flow pathway 12b for providing a flow of effluent being pumped and discharged. The discharge flow pathway 12b may have a discharge flow pathway wall 12c, and is shown with a discharge axis A. The discharge casing 12 may also be configured with a discharge casing insert borehole or orifice 12d that passes from an outer surface 12e of the discharge casing 12 through the discharge flow pathway wall 12c.

The discharge casing insert 14, 140 may include, or be configured with, a discharge casing Venturi plug portion generally indicated as 14a (see Figure 1 B, 2 and 3), 140a (Figures 4 and 5) to be received in the discharge casing insert borehole 12d and arranged at least in part in the discharge flow pathway 12b, e.g., consistent with that shown in Figure 1 B. The discharge casing Venturi plug portion 14a, 140a may be configured with a restricted discharge flow pathway, e.g., which is generally indicated as 14a' and 14a" (see Figures 2A, 3A, 3B), 140a' and 140a" (see Figures 4B and 5B), for providing a partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged from the discharge casing 14. Figure 1 B shows an embodiment of the present that is consistent with that shown in Figures 2 and 3, where the discharge casing Venturi plug portion 14a', 14a" includes a dowel pin 14b', 14b" configured therein, e.g., for providing the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged from the discharge casing 14. In Figure 1 B, the discharge casing Venturi plug portion 14a may be configured with a corresponding discharge flow pathway 14c (or 140c Figures 4 and 5), e.g., having a part or section with a cross-section that may be substantially the same as the cross-section of the discharge flow pathway 12b, and some part or section of the corresponding discharge flow pathway 14c configured with a reduced cross-section that is less than the cross-section of the discharge flow pathway 12b, as set forth herein. Consistent with that shown in Figures 2A and 3A, outer parts or sections of the corresponding discharge flow pathway 14c have the cross-section that is substantially the same as the cross-section of the discharge flow pathway 12b, and an intermediate or middle part or section of the corresponding discharge flow pathway 14c may be configured with the reduced cross-section that is less than the cross-section of the discharge flow pathway 12b, as set forth herein.

In comparison, Figures 4 and 5 show embodiments of the discharge casing Venturi plug portion 140a', 140a" having an inlet, opening or orifice configured or integrally formed therein, e.g., for providing the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged from the discharge casing. Consistent with that shown in Figures 4A, 4B and 5A, 5B, the discharge casing Venturi plug portion 140a', 140a" may be configured with one or more parts or sections of the corresponding discharge flow pathway 140c having a cross-section that is substantially the same as the cross-section of the discharge flow pathway 12b, and some part or section of the corresponding discharge flow pathway 140c configured with a reduced cross-section that is less than the cross- section of the discharge flow pathway 12b, as set forth herein.

By way of example, the discharge casing insert borehole or orifice 12d may be configured along the discharge flow pathway 12b in a position or location as shown in Figure 1 for receiving the discharge casing insert 14. However, the scope of the invention is intended to include, and embodiments are envisioned in which, the discharge casing insert borehole or orifice 12d and the discharge casing insert 14 being configured at a different position or location along the discharge flow pathway 12b. In effect, the scope of the invention is intended to include the discharge casing insert borehole or orifice 12d and the discharge casing insert 14 being positioned or located anywhere in or along the discharge flow pathway 12b within the spirit of the present invention. In other words, the scope of the invention is not intended to be limited to any particular position or location of the discharge casing insert borehole or orifice 12d and the discharge casing insert 14 in or along the discharge flow pathway 12b.

In Figures 1 A and 1 B, the discharge casing 12 is understood to include other parts and components, as a person skilled in the art would appreciate, e.g., that do not necessarily form part of the underlying invention and are not described in further detail.

Figures 2-3: Dowel Pin Arrangements

In Figures 2-3, the discharge casing insert 14 may include, or take the form of, the discharge casing Venturi plug portion 14a configured with a dowel pin bore 14d, e.g., that may be axially drilled into its far end, to receive the dowel pin 14b', 14b", so as to configure the restricted discharge flow pathway 14a' (Figure 2A), 14a" (Figure 3A) to provide the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. In Figures 2A, 3A and 3B, the arrows and reference labels 14a', 14a" point to the restricted discharge flow pathway, for providing the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged from the discharge casing.

In Figure 2, the dowel pin 14b' may be arranged in the dowel pin bore 14d, so as to restrict some part (e.g., an intermediate or middle part) of the corresponding discharge flow pathway 14c and provide the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. In some embodiments, the dowel pin 14b' may be configured as a rod (e.g., a solid rod) having a shaft with a reduced diameter that is less than the cross-section of the discharge flow pathway 12b, so as to restrict some part of the corresponding discharge flow pathway 14c and provide the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. (By way of example, embodiments are envisioned, wherein some portion of shaft may be configured with the reduced diameter, and other portions of the shaft may have a different diameter, e.g., a larger diameter.)

In Figure 3, alternatively the dowel pin 14b" may be configured or formed with an orifice (or opening) 14d' having a reduced cross-section that is less than the cross-section of the discharge flow pathway 12b, so as to restrict some part of the corresponding discharge flow pathway 14c and provide the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. The discharge casing insert 14 may include a set of dowel pins 14b', 14b", where each dowel pin may be configured to be received in the dowel pin bore 14d, and where each dowel pin may also be configured to provide a different-sized partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged, so that performance of the pump may be adjusted based upon the selection of which dowel pin is used from the set of dowel pins so as to provide a desired throat area.

In some embodiments, each dowel pin 14b' may be configured with a respective shaft having a different diameter, where a dowel pin having a larger diameter causes a larger partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged, and where a corresponding dowel pin having a smaller diameter causes a smaller partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged.

Alternatively, each dowel pin 14b" may be configured with a respective orifice having a respective diameter that causes a respective partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. By way of example, the set of dowel pins may include a first dowel pin having a first orifice with a first diameter that causes a first partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged, and may include a second dowel pin having a second orifice with a second diameter that is different from the first diameter and that causes a different- sized partial obstruction than the first partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. The scope of the invention is not intended to be limited to any particular diameter(s) of the shaft or the orifice of the dowel pin.

Figures 4-5: Integrally Formed Restricted Inlet/Opening Arrangements In Figures 4 and 5, the discharge casing insert 140 may include, or take the form of, the discharge casing Venturi plug portion 140a', 140a" configured with an inlet/opening 140d', 140d" that may be drilled or integrally formed therein, e.g., for providing the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged from the discharge casing.

By way of example, the inlet/opening 140d', 140d" may be configured or formed having a reduced cross-section that is less than the cross-section of the discharge flow pathway 12b, so as to restrict some part of the corresponding discharge flow pathway 14c and provide the partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged.

In Figure 4, the orifice 140d' may be configured, shaped or formed with an inlet portion 140d'(in) having a reduced cross-section that is less than the cross- section of the discharge flow pathway 12b, and with an expanding conical portion 140d'(out) having a cross-section that may be less than, substantially the same as, or larger than the cross-section of the discharge flow pathway 12b. Embodiments are also envisioned, and the scope of the invention is intended to include, the inlet portion 140d'(in) and the expanding conical portion 140d'(out), e.g. being reversed so the fluid flows in the opposite direction.

In Figure 5, the orifice 140d" may be configured, shaped or formed with a first expanding portion 140d"(in) that may have a cross-section that is the same or larger than the cross-section of the discharge flow pathway 12b, with an inlet portion 140d"(restricted) having a reduced cross-section that is less than the cross-section of the discharge flow pathway 12b, and also with a second expanding conical portion 140d"(out) having a cross-section that may be less than, substantially the same as, or larger than the cross-section of the discharge flow pathway 12b.

Consistent with that set forth above, the apparatus 10 may include a set of discharge casing inserts 140, each discharge casing insert 140 having a respective Venturi plug portion 140a', 140a", where each discharge casing Venturi plug portion 140a', 140a" may be configured to be received in the dowel pin bore 14d, and where each discharge casing Venturi plug portion 140a', 140a" may also be configured to provide a different-sized partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged, so that performance of the pump may be adjusted based upon the selection of which discharge casing Venturi plug portion 140a', 140a" is used from the set so as to provide a desired throat area.

In some embodiments, each discharge casing Venturi plug portion 140a', 140a" may be configured with a respective orifice having a respective different diameter that causes a respective partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. For example, the set of discharge casing inserts may include a first discharge casing Venturi plug portion 140a', 140a" having a first diameter orifice that causes a first partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged, and may also include a second discharge casing Venturi plug portion 140a', 140a" having a second orifice with a second diameter that is different from the first diameter and that causes a different-sized partial obstruction in the discharge flow pathway 12b and the flow of the effluent being pumped and discharged. The scope of the invention is not intended to be limited to the diameter of the orifice.

Other Features

The discharge casing insert 14, 140 may include a flange portion 14e, 140e for assembling the discharge casing insert 14, 140 to the discharge casing 12, including where the flange portion 14e, 140e is configured with multiple drilled openings 14e1 , 14e2, 14e3, 14e4, 14e5, 14e6, e.g., some of which may be configured to inserting or removing the discharge casing insert 14 to and from the discharge casing 12.

The discharge casing insert 14, 140 may be configured to be removable and replaceable. For example, the discharge casing insert borehole 14d may be configured with threads (not shown); and the discharge casing Venturi plug portion 14a, 140a may be configured with corresponding threads (not shown), so that the discharge casing insert 14, 140 can be screwed into, or screwed out from, the discharge casing 12 so as to be removable and replaceable as needed.

The discharge casing 12 may be configured with a recess 12f; and the discharge casing insert 14, 140 may include a sealing washer 14g configured to be received in the recess 12f of the discharge casing 12 to seal the discharge casing 12 when the discharge casing insert 14, 140 is screwed into the discharge casing 12.

The restricted discharge flow pathway 14a', 14a" may be configured with a geometry that may include, but is not limited to, either a round shape, a triangular shape, a rectangular shape, a square shaped, or an oval shape, which effects pump performance. The scope of the invention is not intended to be limited to shape of the restricted discharge flow pathway, and is intended to include other types or kinds of shapes that are now known or later developed in the future.

The apparatus 10 may include the pump. Possible Applications

Possible applications include at least the following:

Venturi-style pumps or pumps with relatively low specific needs, e.g., including pumps having Ns < or = 1 ,000 (US Units)

By way of example, pump types may include OH1 , OH2, OH3, OH4, OH6, BB1 , BB2 and BB3

The Scope of the Invention

It should be understood that, unless stated otherwise herein, any of the features, characteristics, alternatives or modifications described regarding a particular embodiment herein may also be applied, used, or incorporated with any other embodiment described herein. Also, the drawing herein is not drawn to scale.

Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein and thereto without departing from the spirit and scope of the present invention.