What is the pump :
pumps are mechanical devices that impart energy to a fluid .They are not only very useful, but are excellent examples of hydrostatics. Irrigation Pumps lift water from one elevation to a higher level , overcome friction losses during conveyance , provide pressure for sprinkler operation , and inject chemicals into irrigation systems . Irrigation pumps use mechanical energy to increase the potential pressure and kinetic energy of the irrigation water .
- Centrifugal Pumps
Fluid Properties :
The properties of the fluids being pumped can significantly affect the choice of pump. Key
considerations include:
• Acidity/alkalinity (pH) and chemical composition.
Corrosive and acidic fluids can degrade pumps, and should be considered when selecting pump materials.
• Operating temperature.
Pump materials and expansion, mechanical seal components, and packing materials need to be considered with pumped fluids that are hotter than 200°F.
• Solids concentrations/particle sizes.
When pumping abrasive liquids such as industrial slurries, selecting a pump that will not clog or fail prematurely depends on particle size, hardness, and the volumetric percentage of solids.
• Specific gravity.
The fluid specific gravity is the ratio of the fluid density to that of water under specified conditions. Specific gravity affects the energy required to lift and move the fluid, and must be considered when determining pump power requirements.
• Vapor pressure.
A fluid’s vapor pressure is the force per unit area that a fluid exerts in an effort to change phase from a liquid to a vapor, and depends on the fluid’s chemical and physical properties. Proper consideration of the fluid’s vapor pressure will help to minimize the risk of cavitation.
• Viscosity.
The viscosity of a fluid is a measure of its resistance to motion. Since kinematic viscosity normally varies directly with temperature, the pumping system designer must know the viscosity of the fluid at the lowest anticipated pumping temperature. High viscosity fluids result in reduced centrifugal pump performance and increased power requirements. It is particularly important to consider pump suction-side line losses when pumping viscous fluids
Essential important definition
Fluid: Any substance that can be pumped such as oil, water, refrigerant, or even air.
Gasket: Flat material that is compressed between two flanges to form a seal.
Gland follower: A bushing used to compress the packing in the stuffing box and to control leakoff.
Gland sealing line: A line that directs sealing fluid to the stuffing box.
Horizontal pumps: Pumps in which the center line of the shaft is horizontal.
Impeller: The part of the pump that increases the speed of the fluid being handled.
Inboard: The end of the pump closest to the motor.
Inter-stage diaphragm: A barrier that separates stages of a multi-stage pump.
Key: A rectangular piece of metal that prevents the impeller from rotating on the shaft.
Keyway: The area on the shaft that accepts the key.
Kinetic energy: Energy associated with motion.
Lantern ring: A metal ring located between rings of packing that distributes gland sealing fluid.
Leak-off: Fluid that leaks from the stuffing box.
Mechanical seal: A mechanical device that seals the pump stuffing box.
Mixed flow pump: A pump that uses both axial-flow and radial-flow components in one impeller.
Multi-stage pumps: Pumps with more than one impeller.
Outboard: The end of the pump farthest from the motor.
Packing: Soft, pliable material that seals the stuffing box.
Positive displacement pumps: Pumps that move fluids by physically displacing the fluid inside the pump.
Radial bearings: Bearings that prevent shaft movement in any direction outward from the center line of the pump.
Radial flow: Flow at 90° to the center line of the shaft.
Retaining nut: A nut that keeps the parts in place
Rotor: The rotating parts, usually including the impeller, shaft, bearing housings, and all other parts included between the bearing housing and the impeller.
Score: To cause lines, grooves, or scratches.
Shaft: A cylindrical bar that transmits power from the driver to the pump impeller.
Shaft sleeve: A replaceable tubular covering on the shaft.
Shroud: The metal covering over the vanes of an impeller.
Slop drain: The drain from the area that collects leak-off from the stuffing box.
Slurry: A thick, viscous fluid, usually containing small particles.
Stages: Impellers in a multi-stage pump.
Stethoscope: A metal device that can amplify and pinpoint pump sounds.
Strainer: A device that retains solid pieces while letting liquids through.
Stuffing box: The area of the pump where the shaft penetrates the casing.
Suction: The place where fluid enters the pump.
Suction eye: The place where fluid enters the pump impeller.
Throat bushing: A bushing at the bottom of the stuffing box that prevents packing from being pushed out of the stuffing box into the suction eye of the impeller. Thrust: Force, usually along the center line of the pump.
Thrust bearings: Bearings that prevent shaft movement back and forth in the same direction as the center line of the shaft.
Troubleshooting: Locating a problem.
Vanes: The parts of the impeller that push and increase the speed of the fluid in the pump.
Vertical pumps: Pumps in which the center line of the shaft runs vertically.
Volute: The part of the pump that changes the speed of the fluid into pressure.
Wearing rings: Replaceable rings on the impeller or the casing that wear as the pump operates.
pumps are mechanical devices that impart energy to a fluid .They are not only very useful, but are excellent examples of hydrostatics. Irrigation Pumps lift water from one elevation to a higher level , overcome friction losses during conveyance , provide pressure for sprinkler operation , and inject chemicals into irrigation systems . Irrigation pumps use mechanical energy to increase the potential pressure and kinetic energy of the irrigation water .
Pumps may be classified into :
- Rotary Pumps
Which use gears , vanes , lobes or screw to trap and convey fluid from the inlet to outlet side of the pump
- Reciprocating Pumps
That use the back and forth motion of mechanical parts , such as piston or diaphragms to pressurize the fluid .
Rotary and reciprocating pumps often called positive displacement
pumps , are not used to pump irrigation water primarily because of their
relativity low discharge capacity and susceptibility to sediment laden
water . they are however used to inject chemicals into irrigation
systems
- Centrifugal Pumps
That use the centrifugal force imparted to the fluid by one or more rotating elements ( called impellers ) to increase the kinetic energy and pressure energy of the fluid .
centrifugal pumps use for both of irrigation and chemical injection
Fluid Properties :
The properties of the fluids being pumped can significantly affect the choice of pump. Key
considerations include:
• Acidity/alkalinity (pH) and chemical composition.
Corrosive and acidic fluids can degrade pumps, and should be considered when selecting pump materials.
• Operating temperature.
Pump materials and expansion, mechanical seal components, and packing materials need to be considered with pumped fluids that are hotter than 200°F.
• Solids concentrations/particle sizes.
When pumping abrasive liquids such as industrial slurries, selecting a pump that will not clog or fail prematurely depends on particle size, hardness, and the volumetric percentage of solids.
• Specific gravity.
The fluid specific gravity is the ratio of the fluid density to that of water under specified conditions. Specific gravity affects the energy required to lift and move the fluid, and must be considered when determining pump power requirements.
• Vapor pressure.
A fluid’s vapor pressure is the force per unit area that a fluid exerts in an effort to change phase from a liquid to a vapor, and depends on the fluid’s chemical and physical properties. Proper consideration of the fluid’s vapor pressure will help to minimize the risk of cavitation.
• Viscosity.
The viscosity of a fluid is a measure of its resistance to motion. Since kinematic viscosity normally varies directly with temperature, the pumping system designer must know the viscosity of the fluid at the lowest anticipated pumping temperature. High viscosity fluids result in reduced centrifugal pump performance and increased power requirements. It is particularly important to consider pump suction-side line losses when pumping viscous fluids
Essential important definition
Fluid: Any substance that can be pumped such as oil, water, refrigerant, or even air.
Gasket: Flat material that is compressed between two flanges to form a seal.
Gland follower: A bushing used to compress the packing in the stuffing box and to control leakoff.
Gland sealing line: A line that directs sealing fluid to the stuffing box.
Horizontal pumps: Pumps in which the center line of the shaft is horizontal.
Impeller: The part of the pump that increases the speed of the fluid being handled.
Inboard: The end of the pump closest to the motor.
Inter-stage diaphragm: A barrier that separates stages of a multi-stage pump.
Key: A rectangular piece of metal that prevents the impeller from rotating on the shaft.
Keyway: The area on the shaft that accepts the key.
Kinetic energy: Energy associated with motion.
Lantern ring: A metal ring located between rings of packing that distributes gland sealing fluid.
Leak-off: Fluid that leaks from the stuffing box.
Mechanical seal: A mechanical device that seals the pump stuffing box.
Mixed flow pump: A pump that uses both axial-flow and radial-flow components in one impeller.
Multi-stage pumps: Pumps with more than one impeller.
Outboard: The end of the pump farthest from the motor.
Packing: Soft, pliable material that seals the stuffing box.
Positive displacement pumps: Pumps that move fluids by physically displacing the fluid inside the pump.
Radial bearings: Bearings that prevent shaft movement in any direction outward from the center line of the pump.
Radial flow: Flow at 90° to the center line of the shaft.
Retaining nut: A nut that keeps the parts in place
Rotor: The rotating parts, usually including the impeller, shaft, bearing housings, and all other parts included between the bearing housing and the impeller.
Score: To cause lines, grooves, or scratches.
Shaft: A cylindrical bar that transmits power from the driver to the pump impeller.
Shaft sleeve: A replaceable tubular covering on the shaft.
Shroud: The metal covering over the vanes of an impeller.
Slop drain: The drain from the area that collects leak-off from the stuffing box.
Slurry: A thick, viscous fluid, usually containing small particles.
Stages: Impellers in a multi-stage pump.
Stethoscope: A metal device that can amplify and pinpoint pump sounds.
Strainer: A device that retains solid pieces while letting liquids through.
Stuffing box: The area of the pump where the shaft penetrates the casing.
Suction: The place where fluid enters the pump.
Suction eye: The place where fluid enters the pump impeller.
Throat bushing: A bushing at the bottom of the stuffing box that prevents packing from being pushed out of the stuffing box into the suction eye of the impeller. Thrust: Force, usually along the center line of the pump.
Thrust bearings: Bearings that prevent shaft movement back and forth in the same direction as the center line of the shaft.
Troubleshooting: Locating a problem.
Vanes: The parts of the impeller that push and increase the speed of the fluid in the pump.
Vertical pumps: Pumps in which the center line of the shaft runs vertically.
Volute: The part of the pump that changes the speed of the fluid into pressure.
Wearing rings: Replaceable rings on the impeller or the casing that wear as the pump operates.
I'm grateful for coming across this before I purchased a pump. I wasn't aware that the fluids being pumped could significantly affect what I should choose. I was told it doesn't really matter. http://www.tweedcoastpumps.com.au/
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