A foam pump for generating a foam including a foamable liquid and air has dual, coaxial air and liquid cylinders, each having a respective air and liquid piston which move together during a dispensing operation. In certain embodiments, the air and liquid cylinders are modular, separately formed components. In certain embodiments, a plurality of differently sized, liquid cylinders are provided, each with a corresponding liquid piston which is complementary in size thereto. Providing multiple differently sized liquid cylinder and piston components allows the pump to be configured to deliver a desired quantity of foamable liquid and/or a desired liquid-to-air ratio in the foam output of the pump. The differently sized liquid cylinder and piston components can be used interchangeably with a common air cup design and other common pump components, the modular construction allowing custom pump output configurations to be provided with minimal tooling investment per output size.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A pump for a striping machine includes dual check valves within its piston. At least one of the dual check valves is closed during an upstroke of the piston, thereby ensuring that the pump drives fluid during both its upstroke and its downstroke to maintain a desired ratio between a fluid output by the pump and a material solution output by another pump of the striping machine.

At least one rib 9c, 21c extending in a direction of connecting with a valve cartridge 30 is provided to the inner sides of each of a second connection port 9 of a pump head 5 and a third connection port 21 of a first connecting adapter 20A, and at least one slit 41 which extends in the connecting direction and into which the ribs 9c, 21c are loosely inserted is provided to the lower outer periphery of the valve cartridge 30. The relationship (id2b, id3b)>od1t>(id1, id4)>od2>(id2t, )>od1b is satisfied, where the inside diameter of a first connection port 8 is id1, the inside diameter of the second connection port 9 is id2b , the inscribed diameter at the top of the rib 9c of the second connection port 9 is id2t, the inside diameter of the third connection port 21 is id3b , the inscribed diameter at the top of the rib 21c of the third connection port 21 is id3, the inside diameter of a fourth connection port 23 is id4, the outside diameter of the upper outer periphery of the valve cartridge 30 is od1t, the outside diameter of the bottom of the slit 41 at the lower outer periphery is od1b , and the outside diameter of the upper outer periphery of the valve cartridge 30 is od2.

This valve seat is disposed below a valve ball, wherein the valve seat comprises an annular member in which a seating surface and a lower end surface of the valve ball are formed into a circular shape; a flow path is formed between the seating surface and the lower end surface, for communicating a transfer fluid including a gas and a liquid; and the flow path is formed in a predetermined shape in which a horizontal distance from the central axis which crosses the lower end surface at right angle to the inner circumferential surface of the flow path excluding the seating surface and the lower end surface is not constant over the entire circumference of the flow path.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A striper can apply a polymer-based marking material comprised of a mixture of a material solution and a catalyst. The material solution and catalyst are mixed according to a desired ratio. A first pump drives the material solution and a second pump is slaved to the first pump and drives the catalyst. The second pump includes dual check valves within its piston, thereby ensuring that the second pump drives fluid during both its upstroke and its downstroke to maintain the desired ratio.

A pulse-coupled pump includes a pump body, a low-pressure pump, a high-pressure pump, and a solenoid. The low-pressure pump comprises an armature, an armature sleeve and a rectifying valve. The high-pressure pump comprises a plunger, a sleeve, an inlet valve and a delivery valve. The high-pressure pump is coupled with the low-pressure pump through the armature. The armature, located in the armature sleeve, performs a reciprocating motion driven by magnetic field force of the solenoid, which drives the plunger pump and a forms two-way pulsating liquid. The two-way pulsating liquid can form a directional flow through a rectifying valve. The armature and the armature sleeve are made of magnetically permeable material. The armature sleeve has a non-magnetic gap. The front end of the armature is located near the magnetic gap. The inlet valve is located upstream of the directional liquid flow.

Method and apparatus overcoming gas-lock in reciprocating downhole pumps. On the downstroke of a plunger in a barrel, gassy fluid is compressed in the pump chamber between standing and travelling valves. Downhole plunger movement drags a sleeve over a mandrel for opening a chamber valve to a staging chamber located at a downhole end of the travelling valve for receiving at least a portion of the compressed and gassy fluid therein. On the upstroke, the chamber valve is dragged closed for sealably retaining the compressed gassy fluid therein while drawing an additional increment of fluid through the standing valve into the pump chamber. Continued downstroke and upstroke cycles increases pressure of the compressed gassy fluid in the pump chamber until it exceeds the hydrostatic head above the travelling valve for resumption of normal fluid pumping.

The present invention is a superimposed standing valve and related method of harvesting oil and gas using a conventional rod pump equipped with the superimposed standing valve. The superimposed standing valve includes a donut disposed between a top cylinder and a main standing valve such that the donut can slide along the top cylinder a fixed valve stroke. A plurality of openings are sealed and unsealed by the movement of the donut. The superimposed standing valve isolates the pump from the head pressure of the oil and gas inside of the tubing thereby enabling the standing valve of the pump to remain open on both the upstroke and the downstroke. As a result, the superimposed standing valve increases pump efficiency and reduces the risk of gas locking.