About Reciprocating Pump
It is often used where a relatively small amount of liquid is handled and where the delivery pressure is high. In reciprocating pumps, the chamber that traps the liquid is a stationary cylinder consisting of a piston or plunger.
Types Reciprocating Pump
Simple hand-operated reciprocating pump
Simple hand operated revolving pump. The simplest example is the bicycle pump, which is used everywhere to inflate bicycle tires and various types of sports balls. The name "bicycle pump" is not really the most accurate term because it produces more compression than volume displacement.
Power-operated deep well reciprocating pump
Single-acting reciprocating pump
Consisting of a piston, in which only one side is projected to displace fluid. The simplest example would be a syringe.
Double-acting reciprocating pump
Attach with both sides of the piston, each stroke of the piston completes both suction and removal at the same time. Thus it requires two inflow pipes and two outflow pipes.
Triple-acting reciprocating pump
Many reciprocating types of pumps are simplex (one), duplex (two) or triplex (three) cylinders. Duplex pumps are commonly used where two pumps can be used alternately. Such pumps are commonly used in oil-line pumping, mine de-watering and transfer of chemical and petroleum products, but have many more applications. A triple pump consists of three plungers, intended to reduce the vibrations of a single revolving pump. The Quintuplex pump is designed with a gear case that assists in a high-pressure task. Common applications of which are in cement sludge, sand-filled liquids, crude oil, acids, clays and other oil-filled liquids. Famous manufacturers for this type of pumps are National, Gardner Denver, FMC, SPM, Oilwell, Kerr, Union, Gaso, AMSCO, Aplex and Wheatley.
Reciprocating Pump Part
The main components of reciprocating pump are as follows:
- Suction Pipe
- Suction Valve
- Delivery Pipe
- Delivery Valve
- Piston and Piston Rod
- Crank and Connecting Rod
- Air Vessel
The suction pipe connects the source of the liquid to the cylinder of the reciprocating pump. The liquid from the source to the cylinder is sucked by this pipe.
The suction valve is a non-return valve which means that only one directional flow is possible in this type of valve. This suction pipe is placed between the inlet and the cylinder. It is opened during suction of the liquid and closed during discharge.
The distribution pipe connects the pump's cylinder to the outlet source. Through this pipe the liquid is transported to the desired outlet location.
The delivery valve is also a non-return valve placed between the cylinder and the delivery pipe outlet. It is in closed position during suction and open position during discharge of liquid.
A hollow cylinder made of steel alloy or cast iron. The piston and piston rod are arranged inside this cylinder. The suction and release of liquid are in it, so the valves along with the suction and delivery pipes are also attached to this cylinder.
Piston and Piston Rod
The piston is a solid-type cylinder part that moves back and forth inside a hollow cylinder to suction and distribute the liquid. The piston rod helps the piston in its linear motion.
Crank and Connecting Rod
The crank is a solid circular disk that is connected to a power source such as motor, engine, etc. for its rotation. The connecting rod connects the crank to the piston as a result the rotational speed of the crank is converted to the linear motion of the piston.
A strainer is provided at the end of the suction pipe to prevent the entry of solids from the water source into the cylinder.
Air vessels are connected to both suction and delivery pipes to eliminate the frictional head and to give uniform discharge rate.
Working of Reciprocating Pump
Action 1: The rider or piston is pulled back. The action increases the volume of the cavity. When the volume of the cavity expands, fluid is drawn through the inlet to fill the expansion cavity.
Action 2: The piston has reached it's maximum displacement. Since it is not moving in or out of the cavity, fluid is not flowing from the inlet or outlet.
Action 3:After it reaches its maximum position, it is then pushed back into the cavity. During this process, the piston applies sufficient pressure to the fluid to overcome the pressure at the outlet of the pump. This pressure difference pushes the fluid from inside the cavity through the outlet of the pump.
Action 4: The piston reaches its maximum expansion in the cavity. Here the volume of the cavity is minimum and no fluid is flowing from the inlet or outlet. The next action repeats the process, again the action starts at 1.
Function of Reciprocating Pump
Brake Horsepower (BHP)how much actual power is required on the input shaft to achieve the desired pressure and flow.
CapacityIt can be defined as the total volume of liquid / flow delivered per unit of time.
SlipsSlip is the capacity loss as a fraction or percentage of the suction capacity.
Mechanical efficiencyIts work at full load pressure and speed ranges from 90% to 95% depending on size, speed and construction.
Pressureprimarily, the suction and discharge pressures in a pump.
DisplacementAlso known as GPM, this is the calculated capacity of the pump with no slip loss.