US20210148356A1

US20210148356A1 - Double-action pump cylinder

Info

Publication number: US20210148356A1
Application number: US17/100,079
Authority: US
Inventors: Stephen Paul Stewart
Original assignee: Allied H2o Inc
Current assignee: Allied H2o Inc
Priority date: 2019-11-20
Filing date: 2020-11-20
Publication date: 2021-05-20

Abstract

A pump apparatus for pumping fluid from a well has a cylinder having upper and lower ends with inlet ports, a hollow pump rod defining a plurality of pump rod entry ports, a travelling two-way valve separating a cylinder interior into variable volume upper and lower chambers and first and second one-way valves mounted to the cylinder to seal the inlet ports.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 62/938,044 filed Nov. 20, 2019, which is hereby incorporated by reference.

BACKGROUND

Millions of rural community members and smallholder farmers in sub-Saharan Africa and similar regions face a barrier to accessing sufficient quantities of water from high-yield boreholes. The majority of these boreholes, drilled primarily by government agencies or philanthropic organizations, have been installed with traditional single-action manual pumps which limits the flow rate to approximately four gallons per minute and blocks any alternative access to the water. The proposed cylinder provides a double-action design that can increase the flow rates of these boreholes resulting in shortened queues for drinking water and improved opportunities for irrigating gardens and watering livestock, minimizing the negative impact of dry seasons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an elevation drawing of a complete cylinder assembly.

FIG. 2 shows a half section view of a complete cylinder assembly inside a well casing.

FIG. 3 shows a top view of an upper one-way valve and stuffing box.

FIG. 4 is a section view of the upper one-way valve and stuffing box.

FIG. 5 shows a section view of a lower one-way valve body.

FIG. 6 shows a top view of a one-way seal plate.

FIG. 7 shows a top view of a lower one-way valve assembly.

FIG. 8 shows a section view of the lower one-way valve assembly.

FIG. 9 shows a top view of an inlet spacer.

FIG. 10 shows a section view of an inlet spacer.

FIG. 11 shows a top view of a middle seat.

FIG. 12 shows a full section view of a middle seat.

FIG. 13 shows a top view of a cup seal.

FIG. 14 shows a top view of a two-way seal plate.

FIG. 15 shows a top view of a two-way valve gasket.

FIG. 16 is a cross section showing the two-way valve shuttling as a pump rod descends.

FIG. 17 is a cross section showing the two-way valve shuttling as a pump rod ascends.

FIG. 18 is an elevation drawing of an alternative embodiment of a complete cylinder assembly.

FIG. 19 is a half section view of the alternative embodiment of FIG. 18.

DESCRIPTION OF AN EMBODIMENT

The current disclosure is directed to a pump apparatus with a below-waterline component that is innovative, cost effective, and highly efficient. The below waterline component is a double-action pump cylinder that will operate to a depth of at least 85 feet. The double-action pump cylinder increases the flow rate from the well by eliminating the unproductive portion of each stroke cycle. This is accomplished by terminating a hollow pump rod in a manner that captures a traveling, two-way valve capable of lifting water to the surface on both the up and down portion of each stroke cycle. The pump apparatus can be located inside a cased well and fitted to a mechanized pumpjack or a manually operated design. The double-action pump cylinder disclosed herein may be retrofitted to most international lift-style pump systems that rely on the reciprocation of a pump rod string.
The double-action pump cylinder utilizes an affordable and easily maintained valving system that reduces the number of opposing valves required from four to three while maintaining a full intake of external fluid on each direction of the stroke cycle. This double-action pump system utilizes one-way valves located at the upper and lower ends of the cylinder that operate in line with the pump rod reciprocation and are capable of delivering meaningful quantities of fluid even when located inside a cased well with a small inner diameter, for example a diameter as small as four inches. The double-action pump cylinder disclosed herein includes a valve assembly at the end of a pump rod. The valve assembly, which is a two-way valve, travels with the pump rod and actuates the opposing one-way valves when traveling up or down. The double-action pump cylinder can therefore significantly increase the flow rate over a traditional lift-pump cylinder of equal diameter and stroke length. There are a number of benefits provided by the double-action pump cylinder disclosed including:

- Increased flow rate reduces mechanized operating costs
- Increased flow rate impacts the total volume of water raised per day
- Low cost encourages dedicated below-ground components allowing for custom designed installations, time savings when not required at additional well locations, and protects the water quality of the aquifer
- Raises a specified amount of water (irrigation or drinking) in less time allowing an above-ground mechanical assembly to service multiple locations
- Ability of cylinder and pump rod components to retrofit prevalent international manual water pump installation (e.g., India Mark II and Afridev) increasing the gallon-per-minute yield and potentially resulting in increased number of beneficiaries and shorter wait times
- Provides opportunity to affordably maximize high-yield boreholes with options of larger diameter cylinders, longer stroke lengths, and increased cycle speed
- A common size of pipe, for example a common 1½″ pipe can be used to lower and position the cylinder assembly at the correct depth and support it during actuation and a common size pipe, for example a common ¾″ pipe can provide a robust connection from the surface to the cylinder's internal pump rod. The common 1½″ and ¾″ or other size pipes may be for example PVC pipes
- The cylinder can be easily disassembled by the end user for needed cleaning or replacing of seals

Referring now to the drawings, a pump apparatus 10 comprises a double action pump cylinder 12. Double action pump cylinder 12 may be disposed in a well 5 and utilized to pump fluid therefrom. Well 5 in the embodiment described is a cased well, but pump apparatus 10 may be used in an uncased well also. Double action pump cylinder 12 may be lowered in well 5 on a suspension pipe 16. Double action pump cylinder 12 comprises a cylinder 15 with a cylinder interior 17. Cylinder 15 has upper and lower ends 20 and 25, an upper valve assembly 30 and a lower valve assembly 35. Pump apparatus 10 may further comprise a suspension pipe 16 for lowering the cylinder 15 into the well 5. Upper and lower valve assemblies 30 and 35 are check valves and more particularly are one-way check valves. Pump apparatus 10 includes a pump rod 40 that extends into cylinder 15 through the upper end 15 thereof and is reciprocably disposed therein. A two-way valve 45 assembly is disposed about pump rod 40 and is movable therewith, and is also movable relative thereto. The two-way valve 45 divides cylinder 15 into upper and lower variable volume chambers as more completely described below.
Pump rod 40 is a hollow pump rod defining a pump rod interior 50, and defining a plurality of pump rod perforations, four pump rod entry ports 52 through a wall thereof. Fluid in cylinder 15 is communicated into pump rod interior 50 through pump rod entry ports 52 and is delivered to the surface therethrough. The embodiment shown has four pump rod entry ports 52 spaced equally about the pump rod, but more or less ports may be used. Shoulder 53 is defined on pump rod 40 at the transition to a necked down portion 55, in which pump rod entry ports 52 are defined. Pump rod 40 has upper end 54 which may be connected to a delivery pipe 57 to deliver fluid to the surface. A lower end 56 of pump rod 40 has a seal cap 58 connected thereto. Pump rod 40 thus terminates at travelling two-way valve 45. Seal cap 58 has an upper end 60 that will engage two-way valve 45 during the upward pull of the pump rod 40. During operation of the pump apparatus, pump rod 40 will be reciprocated in cylinder 15. Fluid will enter pump rod interior 50 through the pump rod entry ports 52 on both the upward and downward cycle of the pump rod 40 in cylinder 15.
First, or upper one-way valve 30 is connected an upper end 20 of cylinder 15 and is operable to seal the upper end 20 to prevent flow therethrough during the upward movement of two-way valve 45 and to permit flow therethrough during downward movement of two-way valve 45. Upper valve 30 defines a central opening 62 therethrough. Pump rod 40 passes through opening 62. One-way valve 30 comprises a valve body 64 and a one-way seal plate 66. Valve body 64 defines a plurality of upper inlet ports 68 therethrough at the upper end of cylinder 15. Valve body 64 in the embodiment described has three upper inlet ports. Fluid from well 5 will flow into cylinder 15 through upper inlet ports 68 during the down stroke cycle of the two-way valve 45. The embodiment described includes three upper inlet ports 68.
A stuffing box 70 extends from valve body 64 and is integrally connected thereto. Stuffing box 70 may be separately made and connected to valve body 64. An upper connector 72 connected to stuffing box 70 comprises a gland seal 74 and a threaded extension 76. Extension 76 may be connected to suspension pipe 16. Gland seal 74 is connected to stuffing box 70. Pump rod 40 is sealingly received in gland seal 74 and stuffing box 70 and is reciprocable therein.
Valve body 64 includes a plurality of standoffs 80 and in the embodiment described three valve standoffs 80. Valve standoffs 80 orient the one-way seal plate 66 and limit its vertical travel. One-way seal plate 66 has a scalloped design as shown in FIG. 6. Seal plate 66 defines a plurality of scallops 82 at its outer periphery, and specifically has three scallops 82. Seal plate 66 defines opening 84 therethrough to allow pump rod 40 to pass therethrough. A plurality of cutouts 86 provide clearance for valve standoffs 80. The scalloped design effectively seals each of the upper inlet ports 68, while providing reduced restriction to the flow of incoming water around its perimeter. Washers 88 held in place by fasteners 89 threaded into standoffs 80 limit the travel of one-way seal plate 66. One-way seal plate 66 closes upper inlet ports 68 on the upward cycle of pump rod 40 and two-way valve 45 to block flow therethrough, and moves downwardly to open upper inlet ports 68 on the downward cycle of pump rod 40 and two-way valve 45 to allow fluid from well 5 to pass through upper inlet ports 68 at upper end 20 of cylinder 15.
Lower one-way valve assembly 35 is similar to upper one-way valve assembly 30, but has no stuffing box connected thereto. One-way valve assembly 35 has a valve body 90 with a plurality of standoffs 92 and in the embodiment described three valve standoffs 92. One-way valve assembly 35 has a one-way seal plate 94. Valve standoffs 92 orient the one-way seal plate 94 and limit its vertical travel. One-way seal plate 94 has a scalloped design like that shown with respect to upper one-way valve 30 as shown in FIG. 6. As a result, the seal plate in FIG. 6 shows the numeric indicators for both of seal plates 66 and 94. Seal plate 94 defines a plurality of scallops 95 at its outer periphery, and specifically has three scallops 95. A plurality of cutouts 96 provide clearance for valve standoffs 92. The scalloped design effectively seals each of lower inlet ports 98 defined in valve body 90 at the lower end 25 of cylinder 15, but provides a reduced restriction to the flow of incoming water around its perimeter. Lower valve assembly 35 has three lower inlet ports defined in valve body 90. Washers 100 held in place by fasteners 102 threaded into standoffs 92 limit the travel of one-way seal plate 94. In FIG. 7, one of the standoffs 92 is shown without a fastener 102 and washer 100 so that the cutout 96 and standoff 92 may be seen, but it is understood that a third fastener and washer will be included. One-way seal plate 94 closes lower inlet ports 98 on the downward cycle of pump rod 40 and two-way valve 45 to block flow therethrough, and moves upwardly to open lower inlet ports 98 on the upward cycle pump rod 40 and two-way valve 45 and allow fluid from well 5 to pass through lower inlet ports 98 at lower end 25 of cylinder 15. The use of a neutral buoyancy material will be used to provide a rapid seal for one- way seal plates 66 and 94 and may be, for example, injection molded from polypropylene or polyethylene.
Thus, water, or other fluid from well 5 is directed into cylinder 15 and delivered upward in pump rod interior 50 through pump rod entry ports 52 during both the upward and downward movement of pump rod 40 and two-way travelling valve 45. The upper one-way valve assembly 30 and lower one-way valve assembly 35 are fixed to upper and lower ends 20 and 25 respectively of cylinder 15 by way of tie rods 104 passing through tie-rod tabs 106 and secured by lock nuts 108.
Two-way valve 45 divides cylinder interior 17 into upper and lower variable volume chambers 110 and 112. Two-way valve 45 comprises an upper seal 120, a lower seal 120 a and a two-way seal plate 124 positioned between the upper and lower seals 120 and 120 a. Two-way seal plate 124 has a central opening 125 therethrough. Pump rod 40 is movable such that the pump rod entry ports 52 are movable relative to the two-way seal plate 124. Pump rod entry ports 52 are positioned above the two-way seal plate 124 during upward movement of the travelling two-way valve 45 and below the two-way seal plate 124 during downward movement of the travelling two-way valve 45. Fluid from the lower variable chamber 112 is directed into the pump rod interior 50 through the pump rod entry ports 52 during downward movement of the two-way valve 45 and fluid from the upper variable chamber is directed into the pump rod interior 50 thorough the pump rod entry ports 52 during upward movement of the two-way valve 45.
The upper and lower seals 120 and 120 a may comprise identical cup seals with the lower cup seal simply being inverted. Cup seals 120 and 120 a may be for example standard cup leathers which provide a low cost, readily available, and proven method for an internal-cylinder seal. Additionally, cup leathers deliver a highly efficient means of conveying water with a low ratio of friction regardless of the travel speed of the valve assembly. This is especially beneficial in a solar-powered system to maximize yield during times of reduced energy input. Cup seals 120 and 120 a may be a part of upper and lower seal assemblies 122 and 122 a. Upper seal assembly 122 includes upper seal 120, inlet spacer 126 and middle seat 128. Inlet spacer 126 and middle seat 128, along with cup seal 120 are inverted to form the lower half of two-way valve 45 and are identified with the subscript a. Trapped between the two middle seats 128 and 128 a are two two- way valve gaskets 130 and 130 a located at two-way seal plate 124. Two- way valve gaskets 130 and 130 a have openings 131 and 131 a, and form a part of two-way seal plate 124. The half section view of the assembled components of two-way valve assembly 45 shows a design departure from traditional lift-pump valves in that there is no fixed connection to a solid pump rod. Rather, two-way valve assembly 45 is slidably connected to pump rod 40 so that it moves therewith but is also movable relative thereto.
The double-action pump cylinder thus incudes upper and lower sealing assemblies 122 and 122 a in the two-way valve 45 with a space therebetween. Inlet spacers 126 define a hydrodynamic entry profile 132 to facilitate the transfer of water through its center 134 from the cup seal 120 to an interior 136 of the two-way valve 45. An outer surface 138 of inlet spacer 126 supports and maintains the internal profile of cup seal 120. Middle seat 128 provides a center reservoir 140 where the transfer of water from the interior 136 of two-way valve 45 into pump rod interior 50 occurs. The external profile 142 of a first surface 144 of middle seat 128 provides a contoured support for the base of cup seal 120 on one side and a centering inset 146 on a second surface 148 for the two-way seal plate 124 on the other. Inlet spacers 126 and middle seats 128 may be injection molded from UHMW for durability and dimensional stability under water, but it is understood that other processes for the manufacture are possible, and other materials may be used.
Two-way seal plate 124 with two- way valve gaskets 130 and 130 a are centered and captured between middle seats 128 and 128 a. Opening 125 in the two-way seal plate 124 and the openings 131 in valve gaskets 131 and 131 a have internal diameters that are larger than an outside diameter of the machined neck 55 of pump rod 40 to avoid repeated contact while providing a centralizing stability to a fully lowered pump rod 40 during shipping, installation, and operation. Two-way seal plate 124 functions by being situated between two stationary limits 150 and 152 above and below pump rod entry ports 52. The upper limit 150 is defined on a seal ring 154 disposed about neck 55 below shoulder 53 and the lower limit is defined on seal cap 58. As pump rod 40 is raised and lowered, it shuttles the pump rod entry ports 52 above and below two-way seal plate 124 as two-way seal plate 124 engages stationary limits 150 and 152 to seal one of the opposing variable volume chambers 110 and 112. When seal plate 124 engages top limit 150 the lower chamber 112 is sealed and when seal plate 124 engages lower limit 152 upper chamber 110 is sealed. Stationary limits 150 and 152 limit the travel of two-way valve 45 relative to pump rod 40, such that pump rod entry ports are positioned in the interior 136 of two-way valve 45 to receive water or other fluid in cylinder 15.
The internal two-way valving transition is created by the position of pump rod 40 relative to the two stationary limits 150 and 152. FIG. 16 shows a down stroke with contact between the seal ring 154 and two-way valve gasket 130 on two-way seal plate 124 resulting in an open upper one-way valve 30 and a closed lower one-way valve 35. FIG. 17 shows the results of a small lift of the pump rod 40 as the seal cap 58 now engages the two-way valve gasket 130 a reversing the opposing one- way valves 30 and 35. This shuttling effect brings the traditional four-valve double-action pump systems to a three-valve system while maintaining the full intake of external fluid on each stroke. The volume of the variable upper and lower chambers 110 and 112 changes as the pump rod 40 reciprocates. On the downstroke, water, or other fluid from lower chamber 112 is pushed into pump rod entry ports 52. In the lowermost position of two-way valve 45 upper chamber 110 is filled with water. When the valve 45 is in its uppermost position, the lower chamber 112 fills with water. The upstroke will cause fluid in upper chamber 110 to be pushed into pump rod entry ports 40 and lower chamber 112 will be filled as one-way seal plate 90 a is lifted to open ports 98.
The operation of pump apparatus 10 is evident from the description and drawings. Pump apparatus 10 is lowered into well 5 to a desired depth. Once at the desired depth, pump rod 40 may be reciprocated in cylinder 15 manually, or with any type of mechanized pumpjack that will reciprocate pump rod 40. When pump rod 40 moves downwardly seal ring 154 will engage two-way seal plate 124 to push two-way valve assembly 45 downwardly with pump rod 40. Upper one-way seal plate 66 will move downwardly and fluid from well 5 will pass through upper end 20 of cylinder 15, and specifically through upper inlet ports 68 in valve body 64 into upper variable volume chamber 110. Lower one-way seal plate 94 will be pushed downwardly to cover lower inlet ports 98 in lower valve body 90 to prevent fluid from passing therethrough at lower end 25 of cylinder 15. Pump rod entry ports 52 will be positioned in interior 136 of two-way valve 45 below two-way seal plate 124 and fluid from lower variable chamber 112 will be urged into pump rod interior 50 through pump rod entry ports 52. Fluid is delivered upwardly through pump rod interior 50 to a delivery pipe 57 and ultimately to the surface.
The process is reversed on the upward movement of the pump rod 40. When pump rod 40 moves upwardly, pump rod 40 will move relative to two-way valve 45 until seal cap 58 engages two-way seal plate 124. Upon the engagement of seal cap 58 with two-way seal plate 124 two-way valve assembly 45 is pulled upwardly with pump rod 40. Upper one-way seal plate 66 will move upwardly to prevent flow of fluid from well 5 through upper end 20 of cylinder 15, and specifically to prevent communication of fluid from well 5 through upper inlet ports 68 in valve body 64. Lower one-way seal plate 94 will be pulled upwardly to uncover lower inlet ports 98 in lower valve body 90 to allow fluid to pass therethrough at lower end 25 of cylinder 15 into lower variable volume chamber 112. Pump rod entry ports 52 will be positioned in interior 136 of two-way valve 45 above two-way seal plate 124 and fluid from upper variable chamber 110 will be urged into pump rod interior 50 through pump rod entry ports 52. Fluid is delivered upwardly through pump rod interior 50 to delivery pipe 57 and ultimately to the surface.
An additional embodiment is shown in FIGS. 18 and 19. The pump apparatus 200 of FIG. 18 is similar in many ways to pump apparatus 10. Pump apparatus 200 has double action pump cylinder 202 with generally identical features to double action pump cylinder 12 with a few exceptions. Cylinder 204 has upper and lower portions 205 and 206 with a greater diameter 208 than a diameter 210 of a center portion 211. In addition, a two-way valve 212 does not include inlet spacers or middle seats. Instead, a two-way seal plate 214 has a profile to support upper and lower cup seals 216 and 218, which may be identical to cup seals 120 and 120 a respectively. The operation of the additional embodiment is identical to that described above.
Embodiments disclosed herein include:
Embodiment A: A pump apparatus for pumping fluid from a well that includes a cylinder having upper and lower ends suspended in the well, the upper and lower ends of the cylinder having inlet ports therethrough. A hollow pump rod defining a plurality of pump rod entry ports in a wall thereof communicated with a pump rod interior is reciprocably disposed in the cylinder. A two-way valve is disposed about the pump rod and movable therewith. The two-way valve separates a cylinder interior into variable volume upper and lower chambers. A first one-way valve is mounted to the cylinder above the two-way valve and is operable to seal the inlet ports in the upper end of the cylinder during upward movement of the two-way valve and to allow inflow of water into the upper chamber of the cylinder during downward movement of the two-way valve. A second one-way valve is mounted to the cylinder below the two-way valve and is operable to seal the inlet ports in the lower end of the cylinder during downward movement of the two-way valve and to allow inflow of water into the lower chamber of the cylinder during upward movement of the two-way valve.
Embodiment B: A pump apparatus for pumping fluid from a well includes a cylinder having upper and lower ends and defining a cylinder interior. A hollow pump rod is disposed in the cylinder. The hollow pump rod defines a pump rod interior and defines a plurality of pump rod entry ports communicating the cylinder interior with the pump rod interior. A first check valve at an upper end of the cylinder is configured to permit flow into the cylinder through the upper end thereof and to prevent flow from the cylinder to the well therethrough. A second check valve at the lower end of the cylinder is configured to permit flow into the cylinder through the lower end and to prevent flow from the cylinder to the well therethrough. A travelling valve is positioned between the upper and lower check valves and is movable with the pump rod. Water is directed into and delivered upward in the pump rod interior during both the upward and downward travel of the travelling valve.
Embodiment C. A pump apparatus includes a cylinder disposed in and communicated with a well having fluid therein. A hollow pump rod defines a pump rod interior and is reciprocably disposed in the cylinder. A travelling valve is positioned on the pump rod and is movable therewith and also movable relative thereto, the fluid in the cylinder being delivered into the interior of the pump rod as a result of the reciprocating of the pump rod in the cylinder.
Embodiments A, B and C may have one or more of the additional elements and/or features in any combination.
The pump rod being movable relative to the travelling valve.
The travelling valve comprising an upper cup seal, a lower cup seal, and a two-way seal plate positioned between the upper and lower cup seals.
The pump rod having entry ports that are movable relative to the two-way seal plate, the pump rod entry ports being positioned above the two-way seal plate during upward movement of the pump rod and below the two-way seal plate upon moving the pump rod downward in the cylinder.
Water from the upper variable chamber of the cylinder being directed into the pump rod interior through the pump rod entry ports during the upward movement of the two-way valve in the cylinder and water in the lower variable chamber of the cylinder being directed into the pump rod interior through the pump rod entry ports during the downward movement of the two-way valve.
The upper cup seal comprising an upward facing cup seal and the lower cup seal comprising a downward facing cup seal.
The lower cup seal comprising an inverted upper cup seal.
The upper end of the cylinder defining a plurality of upper inlet ports therethrough and the lower end of the cylinder defining a plurality of lower inlet ports therethrough.
The upper one-way valve configured to block flow into the cylinder through the upper inlet ports during upward movement of the travelling valve and to permit flow therethrough during downward movement of the travelling valve.
The lower one-way valve configured to block flow into the cylinder through the lower inlet ports during downward movement of the travelling valve and to permit flow therethrough during upward movement of the travelling valve.
The pump rod having a lower end terminating at the travelling valve.
An upper limit onto the pump rod and a lower limit on the pump rod, the upper and lower limits positioned to limit the travel of the pump rod relative to the travelling valve.
Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention.

Claims

What is claimed is:

1. A pump apparatus for pumping fluid from a well comprising:

a cylinder having upper and lower ends suspended in the well, the upper and lower ends of the cylinder having inlet ports therethrough;

a hollow pump rod reciprocably disposed in the cylinder, the pump rod defining a plurality of pump rod entry ports in a wall thereof communicated with a pump rod interior;

a travelling two-way valve disposed about the pump rod and movable therewith, the two-way valve separating a cylinder interior into variable volume upper and lower chambers;

a first one-way valve mounted to the cylinder's upper chamber and above the two-way valve and operable to allow the hollow pump rod to reciprocate through its center while allowing a seal to be maintained during increased cylinder pressure between the pump rod and stuffing box; and

a first one-way valve mounted to the cylinder above the two-way valve and operable to seal the inlet ports in the upper end of the cylinder during upward movement of the two-way valve and to allow inflow of water into the upper chamber of the cylinder during downward movement of the two-way valve; and

a second one-way valve mounted in the cylinder below the two-way valve, the second one-way valve operable to seal the inlet ports in the lower end of the cylinder during downward movement of the two-way valve and to allow inflow of water into the lower chamber of the cylinder during upward movement of the two-way valve.

2. The pump apparatus of claim 1, the pump rod being movable relative to the two-way valve in addition to being movable with the pump rod.

3. The pump apparatus of claim 1, the two-way valve comprising;

an upper cup seal;

a lower cup seal; and

a two-way seal plate positioned between the upper and lower cup seals.

4. The pump apparatus of claim 3, the pump rod entry ports movable relative to the two-way seal plate, the pump rod entry ports being positioned above the two-way seal plate during upward movement of the pump rod and below the two-way seal plate upon moving the pump rod downward in the cylinder, water from the upper chamber being directed into the pump rod interior through the pump rod entry ports during the upward movement of the two-way valve in the cylinder and water in the lower chamber being directed into the pump rod interior through the pump rod entry ports during the downward movement of the two-way valve.

5. The pump apparatus of claim 3, the lower cup seal comprising an inverted upper cup seal.

6. The pump apparatus of claim 3, the upper cup seal comprising an upward facing cup seal and the lower cup seal comprising a downward facing cup seal.

7. The pump apparatus of claim 1, fluid from the lower chamber being directed into the pump rod interior through the pump rod entry ports during downward movement of the two-way valve and fluid from the upper chamber being directed into the pump rod interior thorough the pump rod entry ports during upward movement of the two-way valve.

8. A pump apparatus for pumping fluid from a well comprising:

a cylinder having upper and lower ends and defining a cylinder interior;

a hollow pump rod disposed in the cylinder, the hollow pump rod defining a pump rod interior and defining a plurality of pump rod entry ports communicating the cylinder interior with the pump rod interior;

a first check valve at an upper end of the cylinder configured to permit flow into the cylinder from the well through the upper end thereof and to prevent flow from the cylinder to the well therethrough;

a second check valve at the lower end of the cylinder configured to permit flow into the cylinder from the well through the lower end and to prevent flow from the cylinder to the well therethrough; and

a travelling valve positioned between the upper and lower check valves and movable with the pump rod, water being directed into and delivered upward in the pump rod interior during both the upward and downward travel of the travelling valve.

9. The pump apparatus of claim 8, the travelling valve comprising:

an upper seal;

a lower seal; and

a two-way seal plate positioned between the upper and lower seal, the pump rod being movable relative to the two-way seal plate.

10. The pump apparatus of claim 9, the pump rod movable such that the pump rod entry ports are positioned above the two-way seal plate during upward movement of the travelling valve and below the two-way seal plate during downward movement of the two-way seal plate.

11. The pump apparatus of claim 8 further comprising:

the upper end of the cylinder defining a plurality of upper inlet ports therethrough, the first check valve configured to block flow into the cylinder through the upper inlet ports during upward movement of the travelling valve and to permit flow therethrough during downward movement of the travelling valve; and

the lower end of the cylinder defining a plurality of lower inlet ports therethrough, the second check valve configured to block flow into the cylinder through the lower inlet ports during downward movement of the travelling valve and to permit flow therethrough during upward movement of the travelling valve.

12. The pump apparatus of claim 8, the pump rod having a lower end terminating at the travelling valve.

13. The pump apparatus of claim 8, further comprising:

an upper limit on the pump rod; and

a lower limit on the pump rod, the upper and lower limits positioned to limit the travel of the pump rod relative to the travelling valve.

14. The pump apparatus of claim 13 the travelling valve comprising a two-way seal plate in an interior thereof, the pump rod extending through the two-way seal plate, wherein the upper and lower limits engage the two-way seal plate during movement of the pump rod to limit the travel of the pump rod relative to the travelling valve.

15. A pump apparatus comprising:

a cylinder disposed in and communicated with a well having fluid therein;

a hollow pump rod defining a pump rod interior reciprocably disposed in the cylinder;

a travelling valve positioned on the pump rod and movable therewith and also movable relative thereto; and

the fluid being delivered into the interior of the pump rod as a result of the reciprocating of the pump rod in the cylinder.

16. The pump apparatus of claim 15, further comprising:

a seal cap at a bottom end of the pump rod, the pump rod defining a plurality of entry ports communicated with the pump rod interior, the pump rod entry ports positioned in an interior of the travelling valve.

17. The pump apparatus of claim 16 the travelling valve comprising:

an upper seal;

a lower seal;

a two-way seal plate between the upper and lower seal plates, the pump rod sealingly received in an opening in the two-way seal plate.

18. The pump apparatus of claim 17, the upper and lower seals comprising generally identical opposite facing cup seals.

19. The pump apparatus of claim 15 further comprising:

a first check valve at an upper end of the cylinder positioned to allow flow into the cylinder only during downward movement of the pump rod; and

a second check valve at a lower end of the cylinder positioned to allow flow into the cylinder only during upward movement of the pump rod.

20. The pump apparatus of claim 15, the travelling valve dividing the cylinder into variable volume upper and lower chambers, fluid being directed into the pump rod interior from the upper chamber during upward movement of the pump rod and fluid being directed into the pump rod interior from the lower chamber during downward movement of the pump rod.