In this article, we will learn all about hand pump along with definition, parts, how it works, advantages, disadvantages, application, etc. Let’s explore!
What is Hand Pump? Definition
Hand Pump Basics
In simple terms, a Hand pump is a mechanical device or a pump that uses physical manpower to lift water from a well. These are the most basic sorts of pumps that have been in use throughout the years and are still in use in rural areas around the country.
- Hand pumps are regarded as a blessing to humanity because they are utilized to deliver a cost-effective water pumping solution to most isolated regions.
- Water hand pumps come in a variety of shapes and sizes, with most of them sharing a common design and operation.
In this article, we shall get to know the Hand Pump, its working, applications, advantages, disadvantages, and many more, so let’s begin!
What is a Hand Pump?
Hand pumps are manually driven water-lifting machines that can be used to extract water from surface water sources, groundwater sources, and reservoirs, or to pump water through distribution networks.
- Hand pumps are simple to set up and operate, and they’re capable of raising enough water for a small village from depths of up to 80 metres.
- They are extensively utilized in regions where access to power is limited, financial means for investment are limited, and home water consumption is not exorbitant.
- Hand pumps also reduce the risk of people, particularly children, falling into open wells, and also improve the sanitary conditions under which water is drawn off by eliminating the use of soiled buckets, hence decreasing diseases connected with contaminated water.
- A hand pump comes in a variety of forms, which vary based on the depth of the water that needs to be pumped to the ground surface but the working principle is the same.
- There are many various pump models available, including low-cost options that will fit most local conditions.
- Positive displacement pumps are the most commonly used type of hand pumps (such as plunger or piston pumps). However, community participation is required for operation and maintenance, especially if the pumps are regularly used.
Parts of Hand Pumps
A hand water pump is made up of several parts. The following are the main components of the hand pump:
Riser Main Pipe
The vertical pipe that pumps water from the water table to the pump head is known as the riser main pipe.
- It normally has a diameter of roughly 12 to 2 12 inches and is made up of steel pipe sections threaded together or PVC pipe sections that are usually sealed together to prevent leakage.
- The main riser of a closed-top pump cylinder has a smaller diameter than the pump cylinder, whereas the main riser of an open-top pump cylinder has the same diameter as the pump cylinder.
Pump Rod
A pump rod is a solid steel rod with a diameter of about 1⁄2 an inch that is used to link the piston mechanism in the pump cylinder to the pump handle.
The pump handle is responsible for moving the piston assembly and the pump rod either up or down.
Upper Cap
On a closed-top pump cylinder, the upper cap is utilized to seal the interior of the cylinder and to define the piston assembly’s limit of motion.
It’s worth noting that open-top pump cylinders aren’t seen with an upper cover.
Cylinder Barrel
The primary body of the pump cylinder is made up of the cylinder barrel. As the pump continues to run, the piston seals press up against the inside wall of the cylinder barrel to produce a seal that is responsible for creating a pressure difference between the cylinder’s top and bottom components.
Piston Assembly
A plunger is a colloquial name for a piston assembly, which is also known as the business end of a piston pump.
- It is discovered to have a housing made of brass, plastic, or stainless steel that houses the piston valve and piston seals.
- This is attached to the pump rod as well.
- The piston assembly that raises the water out of the well performs this function.
Piston Valve
The piston valve is a one-way valve contained within the piston assembly that permits water to flow upwards in the upper cylinder while closed on the up-stroke pushing water up to the riser main.
Piston Seals
The piston assembly is sealed against the inner walls of the pump cylinder with seals made of leather that have been bathed in oil or seals made of rubber.
- The border between the upper and lower cylinders is defined by the piston seals.
- There is a pressure difference across the piston seals whenever any part of the piston assembly is in motion.
- This pressure difference is what causes water to flow from the bottom of the cylinder to the top and into the riser main.
Foot Valve
The foot valve is a one-way valve positioned inside the lower cap, which is often identical to the piston valve. The foot valve is discovered, which allows water to flow upwardly into the lower cylinder on the up-stroke and stay there on the down-stroke.
Lower Cap
At the bottom of the pump cylinder, the lower cap seals the interior. It houses the foot valve and defines the piston assembly’s downward travel limit.
Tail Pipe
A tail-pipe is an extension of the pump cylinder that is sometimes used when the water level in the aquifer fluctuates or falls below the pump cylinder. By inserting a short length of riser main material into the lower water level, the pump’s operational depth is effectively increased.
Working Principle of Hand Pumps
Positive displacement hand pumps (reciprocating piston or plunger pump) are the most popular type of pump used today.
The hand pump has a straightforward operation and relies on the suction process as its primary mechanism which is explained as below;
- The handle, pump rod, piston, piston valve, suction lift, and water exit are the most critical parts of a hand pump.
- The handle is the most important part of the hand pump when it is in use. The pump can’t suck and extract water from the ground unless the handle is moved.
- To begin, the human raises and lowers the handle to suck and remove water from the ground depth. A piston rod or connecting rod links this handle to the pump piston. This piston moves in perfect agreement with the handle.
- As the handle is lifted, the connecting rod transfers its motion to the piston, which causes the piston to ascend as well. The outlet valve inside the pump shuts as the piston rises, whereas the inlet valve opens.
- Throughout the upward motion of the piston, the water pressure inside the pump cylinder begins to fall below that of the external water, causing a vacuum to form inside the cylinder. Water begins to enter the cylinder as the vacuum inside the pump cylinder builds up.
- The inlet valve shuts when the internal water pressure equals the external water pressure, preventing the cylinder fluid from escaping. The piston begins to move lower when the handle is moved down. The inlet valve remains closed throughout this downward motion, while the output valve opens.
- The water is drawn to the outside through an output valve by the downward action of the piston. The pattern continues as the handle moves upward again.
Types of Hand Pumps
There are many different types of hand pumps that are regularly used. The major ones with their advantages and disadvantages are as below:
Deep-well Hand Pump
- Deep-well Hand pumps are utilized in places where water must be pumped from a deep source. These pumps are employed at depths of up to 15 metres.
- To enable a human in operating this pump, deep well hand pumps comprise the weight of the water that should be lifted and is too high.
- In such circumstances, mechanical aids such as a lever or a flywheel are employed to facilitate the operation.
Pros:
- Mechanical accessories, such as hand wheels or levers, are included with these pumps, making pumping simple. The deep well hand pump is designed to last for a longer time and installation is not difficult.
- Without removing the riser pipe, the foot valve and piston can be readily removed.
- The subsurface sections of this pump are non-corrosive and can survive corrosive water conditions.
- Pumping water on demand does not necessitate the use of a power source or energy. Deep-well hand pumps are appropriate for shallow and deep wells.
Cons:
- To withstand the higher pressure associated with lifting larger water columns, deep well hand pumps must be built with stronger parts.
- In comparison to other types of hand pumps, a Deep-well hand pump requires more time to install, repair, and maintain.
- It takes a lot of force to pump water from a well also this pump’s spare parts are difficult to come by.
Direct Pump
- This type of pump uses the positive displacement principle and contains a pumping rod.
- The direct-acting pump’s pumping rod allows the operator to suck and pull water by moving it directly upward and downward. This hand pump’s only limitation is that it can only lift water up to 15 metres.
- The EMAS pump and the Canzee pump are two examples of direct-action pumps.
- They are simple to install and maintain, but they can only lift up to 15 metres.
Diaphragm Hand water Pump
- A positive displacement pump is also known as a diaphragm pump. The fluid is pumped by a diaphragm in this pump.
- Due to the missing pulling rod, diaphragm pumps have a poor pumping speed. They often include corrosion-resistant parts.
- The most significant disadvantage of a diaphragm pump is that it necessitates a specific tube length and a high-quality rubber membrane. The rubber membrane will ultimately leak, demanding its replacement. As a result of this, the pump expands, and membrane replacement takes a long time.
- Diaphragm pumps used in poor rural regions are frequently discarded when the diaphragm wears out. Moreover, the efficiency of these pumps is weak.
Pros:
- Diaphragm pump has parts that are resistant to corrosion. Its pumping speed is relatively slow. There is no requirement for electricity or any other form of energy.
Cons:
- The efficiency of a diaphragm pump is low. The membrane replacement is time-consuming and costly. The price of these pumps is quite considerable.
Progressive Hand water Pump
- Despite its tiny size, the progressive hand water pump is shown to be more efficient. A helical rotor is fitted inside a double-helical stator in the pumps. The cavity fills with water as soon as the rotor spins, and it is finally pumped out.
- Because of its tiny design, the usual gear mechanism system makes it practically impossible to repair or maintain by a local specialist.
- The pump’s cost is also increased by the fact that it has a standard mechanism.
- A rope and washer pump, as a simple example of a progressive cavity pump, could be one of them.
Pros:
- Progressive hand water pump rotates and flows backward. It also has a long life expectancy and is quite effective.
- Precise flow rate is provided.
- Flow in relation to the speed. Suction power is high. This pump also delivers a steady, low-pulsation flow.
Cons:
- These pumps are unable to function in a dry environment. They can only pump a small amount of water.
- The volumetric efficiency of the pump will be affected if the viscous liquid entering the pump moves too slowly.
- The impeller/stator fittings cause a high slippage ratio, which reduces pump efficiency.
Factors for considering Hand Pumps
The choice of a pump is influenced by a variety of factors, including technical criteria and price, as well as the economic environment (the ease with which spare parts can be obtained and the availability of people who can maintain or repair it), the social environment (public acceptance of the pumping system), and, last but not least, the ease and cost of maintenance.
As a result, certain data will need to be gathered beforehand, including:
- The pump’s intended usage (family, small community, village, and if it is intended for intense use or not)
- The well or borehole’s depth
- The delivery head
- The required pump flow rate
- The water table quality (clear or muddy, packed with sand or caustic waste)
- The community’s price range.
Obviously, price is a crucial consideration when selecting a pump (purchase and installation). It would be pointless to purchase an expensive pump for a shallow, low-cost well.
However, it is not wise to place too much emphasis on the cheapest pumps. Indeed, it appears to be far preferable to pay a little more for a pump that will last longer and be easier to fix and maintain in working order, as well as efficient after-sales servicing and maintenance.
Applications of Hand Pump
- These pumps are commonly used in rural areas because the majority of people in rural areas rely on groundwater for drinking.
- Agriculture is another application for the manual pump.
- It is used to move sludge and slurry.
- For the purpose of oil extraction (lubricating and non-lubricating)
- Paints, varnishes, and Adhesives
- Hand pumps are also useful for applying lotions, creams, and cosmetics.
Advantages of Hand Pump
The advantages of hand pumps are, as follows:
- Sources of power are independent (e.g. diesel, electricity)
- Sufficient output capacity to cover the domestic water needs of small rural groups or families
- The majority of simple hand pumps meet VLOM (Village Level Operation and Management of maintenance) pump requirements and may thus be maintained by adequately trained local caregivers (men or women).
- Hand Pumps make it easy to get drinking water if they are used to withdraw groundwater.
- The level of safety has improved as there is no direct access with buckets and ropes.
Drawbacks of hand Pumps
The disadvantages of hand pumps are, as follows:
- Proper and regular maintenance is essential.
- With increasing depth, the effort required to lift the water increases disproportionally.
- For large communities, the discharge capacity is insufficient.
Conclusion
Hand pumps have become an important part of life for people living in rural areas. For a long-lasting pump without any difficulty, regularly check the tightness of bolts, grease moving parts, and to prevent premature wear of existing shafts on several types of pumps due to the lack of self-lubricating bearings, regularly lubricate moving shafts, and replace the sealing rings on the models concerned to avoid a decrease in pump flow rate and frictional wear of the cylindrical seals.
This can lead to a trouble-free operation for longer days as expected, followed by basic service. Thus to conclude, hand pumps are an excellent solution to effectively and swiftly draw groundwater for various purposes if considered appropriately as per this blog for the exact purpose.
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