Diaphragm pump also known as the membrane pump is a pump which used a combination of reciprocating and a valve either a flapper valve or a ball valve to transfer liquids. However, this type of valve are more convenient to transfer viscous liquids and it is available in different models in electric, engine, manual, air operated or hydraulic configurations. (Wastecorp.com, 2018)
Figure SEQ Figure \* ARABIC 9: Schematic diagram of a diaphragm Figure SEQ Figure \* ARABIC 10: Diaphragm pump
pump (USA, 2014) (1/2&quo, n.d.)
This pump works with the air displacement principle and is connected to by a shaft in centre of the pump. It has two flexible diaphragms that move back and forth to allow fluids to move in and out through the pump and separated the air and the fluid (Verder Liquids, n.d.). The air in the diaphragm chamber is forced out when the diaphragm collapsed. After the diaphragm collapses, it extends to allow the fluid to flow to the diaphragm chamber through the intake line CITATION Min18 \l 2057 (Mineral Processing & Metallurgy, 2018).
Advantages Disadvantages
It is cheaper. The fluid should be clean and free of gas particles
It operates for long term. It can become inaccurate in its metering capability if the valves are blocked.
They are more energy efficient. Table SEQ Table \* ARABIC 4: CITATION Mat181 \l 2057 (Davey, 2018)Applications:
Gear pump
A gear pump is a positive displacement pump that is a constant amount of fluid is pumped at a constant for each revolution and uses the meshing of gears to allow the flow of fluid. However, there are two basic types of gear pump:
Internal pump
It is used to pump thick fluid such as asphalt and adhesive and has a viscosity of 1 cPs to 1,000,000 cPs.

Figure SEQ Figure \* ARABIC 11: Schematic diagram of an internal gear pump Figure SEQ Figure \* ARABIC 12: Internal gear pump
CITATION Int18 \l 2057 (Internal Gear Pumps, 2018) (Barad, 2017)
When the liquid enters the suction port between the exterior and interior gear, it flows through the pump between the gears. The crescent seal divides the liquid and acts as a rotating shaft between the suction and the discharge port. When the pump head is flooded, then liquid flows out of the discharge port and the intermeshing gears of the idler and rotor form locked pocket to assure that the volume is controlled. Then the idler and rotor are connected completely to form a seal which is equidistant from the suction and discharge ports which the allow the fluid to flow out of the pump.
Advantages Disadvantages
Excellent for the use of high viscosity fluids. The speed of flow should be moderated.
Non-pulsating discharge. It has medium pressure limitations.
There is constant discharge of fluid. Overhung load on rotating shaft.
Table SEQ Table \* ARABIC 5: CITATION Sud13 \l 2057 (S.V.R, 2013) CITATION Sud13 \l 2057 (S.V.R, 2013)Applications:
External pump
External gear pump is one which is used as lubricating pump in machine tools, fluid power transfer units and as oil pumps in engines and also it also uses two external spur gears. However, large capacity external pump uses helical or herring bone gears and operates at 640 rpm whereas the small capacity external pump operates between 1750 to 3450 rpm. This pump is used where there is the use of polymers, fuels, and chemical additives.
Figure SEQ Figure \* ARABIC 13: Schematic diagram of an external Figure SEQ Figure \* ARABIC 14: External gear pump
gear pump CITATION Ind18 \l 2057 (Industrial Hydraulics, 2018) CITATION And \l 2057 (Vacca, 2018)Mechanism
The external pump consists of two identical rotating gears one is the drive gear and the other is the slave gear. When liquid flows into the pump, it is trapped with the rotating gears. The liquid then flows in the pockets found between the gears and the casing. As the gears rotate, they allow the liquid to flow out of the pump.
Advantages Disadvantages
The fluid flows at a high rate. No solids are allowed to pass through the pump.
No overhung bearings. It has four bushing in the liquid area.
It doesn’t make too much noise when it operates. It has fixed end clearances.
Table SEQ Table \* ARABIC 6: CITATION Sud13 \l 2057 (S.V.R, 2013) CITATION Sud13 \l 2057 (S.V.R, 2013)Applications:
Peristaltic pump
Peristaltic pump is used for a variety of viscous fluids. In a peristaltic pump, the fluid flows through a flexible tube fitted inside a circle casing. This casing consists of a rotor attached to a number of rollers. However, peristaltic pump uses an alternating compression and relaxation system. CITATION Rin10 \l 2057 (Raj, 2010)35718751117600005461000
Figure SEQ Figure \* ARABIC 15: Schematic diagram of a peristaltic pumps Figure SEQ Figure \* ARABIC 16: Peristaltic pumps
CITATION Pum18 \l 2057 (Pumps and Pumping Equipments, 2018) CITATION Col18 \l 2057 (Cole-Parmer, 2018)
The pumps system in a peristaltic is known as peristalsis. The rollers are passed along a tube to creates a temporary seal between the suction and the discharge. When the fluid enters the tube, it is pushed away towards the outlet when the rollers attached to the central of the rotor rotates. The speed of rotation of the rollers controls the rate of flow of the fluid. If the speed of rotation increases, the rate of flow of the fluid increases also.
Advantages Disadvantages
It is cost effective. The tube should change often.
It is easy to maintain. The operator should have a good knowledge in peristaltic pumps.
It is easy to sterilize. Selection of tube is difficult.
Table SEQ Table \* ARABIC 7: CITATION Rin10 \l 2057 (Raj, 2010)Applications:
Case Study
This case study is about the type of pump used at my house.
As I have observed there is no pump connecting to the water pipes. However, there is an issue with the flow rate of the water. Since the house is a storey house and the water tank is on roof, it is difficult for the tank to fill quickly as the flow rate of the water is very low. Therefore, it will be easier if there would be a by connected to main water stream.
The recommended water pump is a pressure booster water pump. This is because a pressure booster water pump is connected directly to the main water stream of the house.
The pressure booster pump has a:
Pressure range between 80 to 315 Psi.
It can pull the fluid at a maximum length of 15 ft.
It can support water at a maximum temperature of 140°F.
Since it is a storey house, it is easier to use a pressure booster water pump since it the fluid can travail up to 15 ft at a high flow rate.

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