Hydraulic Structures: Tube Wells and Components

Job #01

• Objective: Study various components of tube wells and allied hydraulic structures.
• Theory: Tube wells are hydraulic structures below ground level for exploiting groundwater via pumping machinery. They include suction pipes (blind and filter foot valve), delivery pipes, engines, pumps, sumps, and discharge boxes. Field stations of the Department of Irrigation and Sindh Agriculture University (Tandojam) will be virtually visited.
• Blind/Plane Pipe: Converts impervious layers, facilitates upward vertical water movement from aquifers via pumping. Made of mild iron or PVC.
• Suction Well Pipe: Conducts water from underground reservoirs (aquifers) to the pump for lifting to the surface. Often called the tube well pipe.
• Screen/Filter: Special pipe section with holes. Helps prevent coarse sand and particles from entering the well while allowing water to pass through.
• Foot/Check Valve: Allows water flow in one direction. Prevents water loss from the suction pipe when the pump stops. Also known as foot valve.

Gate Valves

• Various types: Used in water conveyance and distribution systems.
• Purpose: Essential to shut off water flow during repairs.

Pumps

• Mechanical devices: Lift water from aquifers to usable levels.
• Conversion: Convert mechanical energy into hydraulic energy.
• Strong Vacuum: Create strong vacuum for effectively drawing water from deeper layers.
• High Velocity: Transport water through pipes and delivery channels.
• Pump types: In shallow tube wells, centrifugal pumps are common due to their cost effectiveness.

Engines/Motors

• Energy source: Provide energy requirements for pumps (HP) and revolutions per minute (RPM) tailored to pumping needs.

Delivery/Discharge Pipe

• Function: Carries pumped water either directly to the field or to a discharge box.
• Elevated placement: Elevated 5-6 feet above ground for proper water flow.
• Discharge Box: A hydraulic structure at ground level near the tube well for holding water and dispersing it into field or irrigation systems.

Pump/Engine House

• Construction: Brick construction on the ground surface for protection and security of equipment in tubewells, and size is relevant to the system.
• Size: 12ft x 10ft x 9ft for small operations, larger for greater space requirements.

Bends, Sockets and Flanges

• Connection parts: Connect different components (e.g., pipes) in tube well systems
• Connection function: Used in tubewell assemblies to connect various sections efficiently.

Job #02

• Objective: To determine discharge values of tube wells using a horizontal trajectory method.
• Needed Material: Tube well, angle iron, measuring scale.
• Theory: Calculating Discharge: Discharge calculation involves measurements made in the pipe using vertical and horizontal factors and determined by the flow rate and pipe diameter.
• Procedure(Full flow pipe): Measure horizontal(x) and vertical (y) positions taken across flow. Record the measurements. Determine the diameter of the pipe(D)
• Procedure(Partially filled pipe): Follow same process as the full flow pipe but note the measurements taken at various points along the pipe.

Volumetric Method

• Objective: Determine discharge via volumetric method.
• Necessary material: A tubewell, drum, stopwatch ,scale.
• Theory: Essential for water quality assessment for agricultural and domestic use.
• Procedure:Collect the water, measure the time taken, and use relevant formulas to determine discharge given collected volumes over a specific time.

This quiz explores the components and functioning of tube wells, focusing on their role in groundwater extraction. Learn about essential parts like suction pipes, delivery pipes, and various valves while virtually visiting key irrigation field stations. Test your understanding of hydraulic structures that support agricultural practices.