Use Fluids in Engineering





This unit covers the competency to solve problems relating to water flow in open channels and/or pipes.


40 hours

Employability skills

The required outcomes described in this unit of competency contain applicable facets of Employability Skills.

The Employability Skills Summary of the qualification in which this unit of competency is packaged will assist in identifying Employability Skills requirements.

Pre/co-requisite units

Pre requisite – Use Basic Fluids in Engineering


This unit applies to technician level activities in a civil engineering environment.





Elements describe the outcomes of a unit of competency.


Performance Criteria specify the level of performance required to

demonstrate achievement of the Elements. Terms in italics are elaborated in the Range Statement.

1. Calibrate various weirs and notches.

1.1.     Differentiate between weirs and notches

1.2.     State formula for the theoretical discharge over various notches and weirs and use these to solve weir problems.

1.3.     Conduct laboratory work to determine coefficient of discharge and produce calibration curves for various

weirs and notches

2. Determine flow rates in an open channel

2.1      State Chezy and Manning formula.

2.2      Calculate flow rates in open channels.

2.3      Describe how gauging stations operate and how they are used in the management of water resources.

3. Solve stability problems for floating objects.

3.1      State Archimedes principle.

3.2      Determine the upthrust on a partly submerged body.

3.3      Determine if a partly submerged body is stable.

4. Determine the friction losses in a pipe network.

4.1      Determine the friction factor using a Moody diagram

4.2      Calculate the head loss due to friction using the Darcy – Weisbach equation.

4.3      Calculate the minor head loss in a pipeline.

4.4      Graphically represent the THL and the HGL at no flow and when flow takes place.

5. Determine forces on submerged plates

5.1      Determine the magnitude of the force acting on a submerged plate.

5.2      Determine the position of the force acting on a submerged plate.

5.3      Calculate the required mass of a counter weight attached to a flap type gate used to control flow in a


6. Select pumps for a given fluid system

6.1      Categorise pumps into displacement and rotodynamic.

6.2      Explain the method of operation of a reciprocating pump and a centrifugal pump.

6.3      Explain how cavitation is caused and how it can be prevented.

6.4      Identify elements of a pump performance curve




This describes the essential skills and knowledge and their level required to complete this unit.


Essential knowledge:

  • Formulae for discharge over weirs and
  • Chezy and Manning formulae for flow in an open channel
  • Archimedes principle
  • Centre of buoyancy and metacentric height
  • Formulae for minor losses in a pipe network – “k” factors
  • Darcy – Weisbach equation for friction loss in
  • Formulae for the magnitude and position of forces on submerged objects
  • Fluid mechanics principles relating to the operation of displacement pumps and rotodynamic pumps.


Essential skills:

Ability to:

  • Determine from a Moody diagram a value for the friction
  • Determine friction losses in a pipe network
  • Graph THL and HGL for a pipe network
  • Relate the THL and HGL to pipeline
  • Perform a test on a pump to determine its operating characteristics and hence produce a pump performance
  • Select a suitable pump to be included in a pipe
  • Calculate flow rates in either an open channel or a closed
  • Determine the stability of a floating





The Range Statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Add any essential operating conditions that may be present with training and assessment depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts.

various weirs and notches may include

·         Broad crested weirs

·         Rectangular and V notches

·         Combinations or rectangular and V notches

·         Suppressed and non suppressed weirs

minor head loss may include

·         Losses due to sudden expansion, sudden contraction, entry and exit.

·         Losses due to fittings like valves and bends

elements of a pump performance curve may include

·         Head

·         Discharge

·         Efficiency

·         Power

·         NPSHR

·         Impeller diameter





The evidence guide provides advice on assessment and must be read in conjunction with the Performance Criteria, Required Skills and Knowledge, the Range Statement and the Assessment Guidelines for this course.

Critical aspects of assessment and evidence required to demonstrate this competency unit:

·         Correct units must be used for all quantities.

·         Correctly determine flow rates through a fluid system.

·         Produce calibration graphs for notches to an appropriate industry standard.

·         Reports related to testing of pumps are documented in an appropriate industry format.

Access and equity considerations:

The assessment environment should not disadvantage the candidate.

Context of and specific resources for assessment:

This unit may be assessed on the job, off the job or a combination of both on and off the job. Where assessment occurs off the job, that is the candidate is not in productive work, then an appropriate simulation must be used where the range of conditions reflects realistic workplace situations. The competencies covered by this unit would be demonstrated by an individual working alone or as part of a team.

Method of assessment:

Assessors should gather a range of evidence that is valid, sufficient, current and authentic.

Evidence can be gathered through a variety of ways including direct observation, supervisor’s reports, project work, samples, questioning, workplace-supervised practicals, remote labs, simulations, video, assignments, quizzes, scenario participation, e-portfolios and other techniques as required.

Questioning should not require language, literacy and numeracy skills beyond those required in this unit.

The candidate must have access to all tools, equipment, materials and documentation required and must be permitted to refer to any relevant workplace procedures, product and manufacturing specifications, codes, standards, manuals and reference materials.


Software/Hardware Used