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Discflo (tm) Pump Gear Pump
Basic Impeller Mechanism Jet Pump (Wells)
Peristaltic Pump Piston Pump
Progressive Cavity Pump Radial Piston Pump
Screw Pump Simplex Pump
Swash Plate Piston Pump Turbine Pump
Vacuum Pump Vane Pump
Volute Pump Wobble Plate Piston Pump


Discflo  Pump    

The Discflo (tm) pump is manufactured by Discflo Corporation. It uses LAMINAR FLOW to achieve a low-maintenance pump which is virtually impervious to clogging, making it ideal for many wastewater industry applications.

Laminar Flow is a smooth, gentle flow, without abrupt changes in direction or pressure. By utilizing this flow, the pump surfaces ("rotary discs") are not damaged as much as with other pumps, because the liquid nearest them is flowing at nearly the same speed as the "rotary disc" surface itself.

The unique shape of this pump enables it to use laminar flow -- the pump is made of flat disks, or disks with small ridges on them. These disks produce a non-pulsating, smooth flow which reduces wear.

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Gear Pump

This is a type of Rotary Force Pump. Gear pumps are extremely simple and reliable.

Depending on the number of teeth, the "idler" gear might be driven directly by the "drive" gear. Generally with six or more teeth this is possible. In other cases an extra gear external to the pump drives the secondary gear at the same rate.

The teeth on Gear Pumps can be spur (straight), helical (slanted), herringbone, etc. There can be two, or more teeth on each gear -- twenty is not uncommon. The diameter of the gears and their thickness varies widely.

The many variations have different effects on the efficiency, strength, smoothness and other areas of operation.

This pump will pump in the reverse direction if you reverse the direction of rotation of the gears. Two pairs of valves can be added to make this a Reversing Gear Pump, which pumps in the same direction regardless of which direction the gears rotate.

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Impeller Mechanism

Probably this is the most versatile pump of all. Impeller mechanisms are the basis of thousands of types of pumps.

The number of blades can vary from 1 to 10 or more. They operate over a wide speed range -- from less than 30 to more than 3000 RPM.

Impeller pumps are excellent for moving impure liquids since they do not clog very easily. For very impure liquids such as sludge, a single blade is sometimes used.

Impeller pumps range in diameter from less than a quarter inch to 10 feet or more. Sometimes they have diffusers to increase efficiency.

Sometimes the output of one impeller is fed directly into another impeller to increase the head. As many as six or ten might be linked together, or connected in two facing sets to double the output and even the pressures on the shaft and pump casing.

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Jet Pump

A Jet Pump is a type of impeller-diffuser pump that is used to draw water from wells into residences. It can be used for both shallow (25 feet or less) and deep wells (up to about 200 feet.)

Above the surface would be a standard impeller-diffuser type pump. The output of the diffuser is split, and half to three-fourths of the water is sent back down the well through the Pressure Pipe.

At the end of the pressure pipe the water is accelerated through a cone-shaped nozzle at the end of the pressure pipe. Then the water goes through a Venturi in the Suction Pipe.

The Venturi has two parts: the Venturi Throat, which is the pinched section of the suction tube; and above that is the Venturi itself which is the part where the tube widens and connects to the suction pipe.

The Venturi speeds up the water causing a pressure drop which sucks in more water through the intake at the very base of the unit. The water goes up the Suction Pipe and through the impeller -- most of it for another trip around to the Venturi.

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Peristaltic Pump

One of the main advantages of the Peristaltic Pump is cleanliness. It also utilizes another advantage: Fragile blood cells are not damaged by this pump.

The flexible tube is connected on the inlet side to the patient's artery, and on the outlet side to the patient's vein.

In this example three rollers on rotating arms pinch the tube against an arc and move the fluid along. There are usually three or four sets of rollers.

Peristaltic pumps have a variety of medical applications. They can be used to add nutrients to blood, to force blood through filters to clean it, or to move blood through the body and lungs during open heart surgery.

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Piston Pump

The basic Piston Pump is very simple having just two valves and one stuffing box.

The reciprocating piston is driven back and forth by a rotating mechanism.

This piston pump uses suction to raise water into the chamber. The lower valve can be placed below water level.

The piston must be within about 25 feet of the water level, but the water can then be raised quite high.

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Progressive Cavity Pump

Progressive (or Progressing) Cavity pumps, is a type of Single Screw pump, are used for highly viscous liquids such as peanut butter or glue, and also for liquids with significant amounts of solids such as cement or sand slurry.

Fluid proceeds from the entrance, at the top on the right side, to the left. The rotor revolves inside the stator.

The stator is a twisted cavity with an oval-shaped cross-section. It is usually made of natural or synthetic rubber, steel, or plastic. The rotor is usually steel.

For a given diameter and shape of the rotor, doubling the number of stages (the length) will double the output pressure.

The area of the cross-section of the rotor determines the backpressure the pump must withstand.

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Radial Piston Pump

Radial Piston Pumps can produce a very smooth flow under extreme pressure. Generally they are variable-displacement pumps.

In variable models, flow rate changes when the shaft holding the rotating pistons is moved with relation to the casing (in different models either the shaft or the casing moves.) Output can also be varied by changing the rotation speed.

If the casing is moved to the left, the flow rate would decrease to zero. If it is moved even further to the left the flow would reverse.

Input is through the two black holes near the center below the "Pintle" . Output is through the top two black holes, above the Pintle.  Higher pressure areas are indicated with a lighter blue fluid color.

The pistons are usually forced out by springs. They are forced back in, expelling liquid, by the casing.

An odd number of pistons is always used to smooth the hydraulic balance. These pumps revolve at speeds up to about 1200 RPM.


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Screw Pump

The screw pump is a positive displacement pump which comes with two or three screws. (A single screw version is called a "progressing cavity" pump.)

The Quimby Screw Pump is a type of screw pump.

The pump forms hollow cavities which contain the fluid and move it along the screws. One screw is the drive screw and the other screw or screws is/are driven by the drive screw.

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Simplex Pump

The Simplex, or Single-Cylinder Double Acting, Pump was invented in 1840 by Henry R. Worthington.

A Simplex Pump is a reciprocating pump. This pump has a single liquid cylinder which forces liquid out through the top outlet on both the in and the out stroke (here up and down.)

This basic type of pump might be used for Air Pumps, Feed Pumps for the furnace, Fire, Bilge, and Fuel Oil Service. All might rely on this fundamental pump.

The DUPLEX PUMP is similar to the Simplex pump, having two pistons instead of one, providing smoother operation. From the outside, a simplex pump can take many forms but the basic concept

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Swash Plate Piston Pump

Swash plate pumps have a rotating cylinder containing pistons. A spring pushes the pistons against a stationary swash plate, which sits at an angle to the cylinder.

The pistons suck in fluid during half a revolution and push fluid out during the other half.

On edge of the Piston Pump, the far right is a dark stationary disk. It contains two semi-circular ports. 

These ports allow the pistons to draw in fluid as they move toward the swash plate (on the backside) and discharge it as they move away.

For a given speed swash plate pumps can be of fixed displacement like this one, or variable by having a variable swash plate angle. The greater the slant the further the pistons move and the more fluid they transfer.

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Turbine Pump

Turbine pumps typically have a high head and high discharge pressure for their size and speed. It is not uncommon for turbine pumps to produce heads over 1000 feet, at relatively low RPM compared with other pumps.

This high head from a single rotating impeller is caused by the unique operation of the pump.

As fluid goes from intake to discharge (in just under one revolution) it circulates around and around.  Each time it passes the turbine blades  it gains additional pressure.

For relatively low flow rates this pump is often more efficient than a comparably-sized centrifugal pump.

This pump is commonly used for clean fluids of low viscosity because of the close tolerances needed between the blades of the turbine and the casing.

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Vacuum Pumps

A vacuum pump removes air from a container to create a vacuum. Force pumps of many types are used for vacuum pumps including Rotary pumps and Piston pumps.

This vacuum pump is a piston pump. With each cycle it removes a smaller number of air molecules until it just keeps up with what is leaking in past the joints and valve seats.

The amount of vacuum at that point depends on the quality of the components -- how fast the valves close, how tight the seals are, etc.

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Vane Pump

A very common type of pump, this is one of many variations.

Power steering units often rely on a vane pump to obtain the pressure needed for the Power Cylinder.  Automatic transmissions often use them too.

The vanes are in slots in the rotor.  When the rotor spins, centrifugal force pushes the vanes out to touch the casing, where they trap and propel fluid. Sometimes springs also push the vanes outward.

When the vanes reach the return side they are pushed back into the rotor by the casing. Fluid escapes through a channel or groove cut into the casing, shown here on the lower right side in black.

On a vane pump there is considerable unbalanced force on the drive shaft, since the high-pressure, outlet area is all on one side. Vane pumps can be designed in balanced configurations where there are two inlet and two outlet ports, similar to balanced gear pumps.

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Volute Pump

A volute is a curved funnel increasing in area to the discharge port. It is often used with impeller pumps. As the area of the cross-section increases, the volute reduces the speed of the liquid and increases the pressure of the liquid.

One of the main purposes of a volute casing is to help balance the hydraulic pressure on the shaft of the pump. However, this occurs best at the manufacturer's recommended capacity. Running volute-style pumps at a lower capacity than the manufacturer recommends can put lateral stress on the shaft of the pump, increasing wear-and-tear on the seals and bearings, and on the shaft itself.

This cutaway of a 'high-end' magnetic drive pump shows the volute wrapping around the impeller at the top and bottom. The ring to the left of the upper part of the volute is for lifting the pump and is located at the balance point.

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Wobble Plate Piston Pump

This pump has pistons in a stationary block, and a rotating wobble plate. There might be 4, 5, or more pistons (usually an odd number are used).

Each piston has a valve within it and another valve behind it. Fluid comes in on the wobble plate side and exits under pressure in the back .

The pistons are pushed against the wobble plate with large springs. A pair of smaller springs force the valves (small metal balls) closed. The spring inside the piston is fairly weak, since only suction is used to force it open.

This type of pump can develop incredible pressure -- 10,000 P.S.I. or more. It is commonly used for low-volume applications. Hand-operated wobble pumps were used as emergency fuel pumps on some early aircraft.

Compare this pump, also known as a "wabble" plate pump, to the radial piston pump, swash plate pump, and bent axis pump.

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