All qualifications and unit standards registered on the National Qualifications
Framework are public property. Thus the only payment that can be made for
them is for service and reproduction. It is illegal to sell this material for profit. If
the material is reproduced or quoted, the South African Qualifications Authority
(SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY
Demonstrate understanding of the principles of fluid power
FIELD DESCRIPTION
Manufacturing, Engineering and Technology
SUBFIELD DESCRIPTION
Manufacturing and Assembly
NQF LEVEL
CREDITS
2
6
PURPOSE OF THIS UNIT STANDARD:
The skills, values and knowledge reflected in this unit standard are required by people in the field of
Fluid Power Engineering who are required to interpret schematics, fault find and maintain electrohydraulic systems. The learning outcomes in this unit standard also contribute to the exit level
outcomes required for the fluid power NQF Level 2 qualification.
Persons credited with this unit standard are able to:




Demonstrate understanding of basic physics.
Demonstrate understanding of fluids and fluid flow.
Demonstrate understanding of flow and pressure.
Demonstrate understanding of fluid power conversion to mechanical power.
RANGE STATEMENTS:
Specific range statements are provided in the body of the unit standard where they apply to
particular specific outcomes or assessment criteria.
LEARNING ASSUMED TO BE IN PLACE:
The credit calculation is based on the assumption that a person is already competent in terms of
the following outcomes when starting to learn toward this unit standard.
 Mathematics at NQF level 2
1
SPECIFIC OUTCOMES AND ASSESSMENT CRITERIA
Specific Outcome 1:
Demonstrate understanding of basic physics.
Assessment Criteria:
1.1
Physics terms are described with reference to international definitions.
Range : This will include energy, work done, force, pressure, power, velocity and
acceleration.
1.2
Symbols and SI units are explained in terms of basic measurement units.
Range : Symbols and SI units include distance, flow, force, mass, power, pressure,
speed, temperature, time, torque, volume, acceleration, angle and area.
1.3
Basic mathematical relationships between physics terms are explained with reference to
international standards.
1.4
Types of energy transfer are explained with reference to fluid power.
1.5
Energy transfer between air and fluid are explained in terms of advantages and
di sadvantages.
Specific Outcome 2:
Demonstrate understanding of fluids.
Assessment Criteria
2.1
Fluid power terms are described with reference to international definitions.
Range : This will include volume, flow, density, viscosity and viscosity index.
2.2
The effects of turbulent and laminar flow are explained with reference to pressure drops.
2.3
The effect of temperature on hydraulic fluid is explained with reference to viscosity.
2.4
The relationship between compressibility and pressure is explained with reference to
hydraulic fluid and air.
Specific Outcome 3:
Demonstrate understanding of fluid flow and pressure.
Assessment Criteria
3.1
E nergy conservation is explained with reference to Bernoulli’s principles.
3.2
The relationship between fluid flow, velocity and cross sectional area is explained with
reference to hydraulic fluid and air.
3.3
The relationship between pressure loss, fluid velocity and cross sectional area is explained
with reference to hydraulic fluid and air.
3.4
Fluid velocity in a given pipe is calculated and compared to recommended industry
2
standards.
Range :
Pipes include suction, pressure, return, and drain lines
Specific Outcome 4:
Demonstrate understanding of fluid power conversion to mechanical power.
Assessment Criteria
4.1
The relationship between fluid flow and linear velocity is explained with reference to a
hydraulic or pneumatic cylinder.
4.2
The relationship between pressure and force is explained with reference to a hydraulic or
pneumatic cylinder.
4.3
The relationship between fluid flow and angular velocity is explained with reference to a
hydraulic motor.
4.4
The relationship between pressure and torque is explained with reference to a hydraulic
motor.
ACCREDITATION AND MODERATION OPTIONS:
 Anyone assessing a learner against this unit standard must be registered as an assessor with
the relevant ETQA.
 Any institution offering learning that will enable achievement of this unit standard must be
accredited as a provider through the relevant ETQA by SAQA.
 Moderation of assessment will be overseen by the relevant ETQA according to the moderation
guidelines and the agreed ETQA procedures.
NOTES:
1.
CRITICAL CROSS -FIELD OUTCOMES:
The following critical cross-field outcomes are addressed in this unit standard:
1.1 Identify and solve problems and make decisions using critical and creative thinking.
Note: The ability of the candidate to identify difficulties and take appropriate action.
1.2 Work effectively with others as members of a team, group, organisation or community.
Note: This outcome is not met in this unit standard.
1.3 Organise and manage themselves and their activities responsibly and effectively.
Note: This outcome is not met in this unit standard.
1.4 Collect, analyse, organise and critically evaluate information.
Note: The ability of the candidate to gather relevant information relating to fluid power
principles.
3
Formatted: Bullets and
Numbering
1.5 Communicate effectively, using visual, mathematical and / or language skills in the
modes of oral and / or written presentations.
Note: This outcome is not met in this unit standard.
Formatted: Bullets and
Numbering
1.6 Use science and technology effectively and critically showing responsibility towards the
environment and health of others.
Note: The ability of the candidate to integrate physics principles in fluid power.
Formatted: Bullets and
Numbering
1.7 Demonstrate an understanding of the world as a set of related systems by recognising
that problem-solving contexts do not exist in isolation.
Note: The ability of the candidate to integrate physics principles in fluid power.
2.
EMBEDDED KNOWLEDGE:
Essential embedded knowledge will be assessed through assessment of the specific
outcomes in terms of the stipulated assessment criteria. Candidates are unlikely to achieve
all the specific outcomes, to the standards described in the assessment criteria, without
knowledge of the listed embedded knowledge. This means that for the most part, the
possession or lack of the knowledge can be directly inferred from the quality of the
candidate’s performance. Where direct assessment of knowledge is required, assessment
criteria have been included in the body of the unit standard.
The following embedded knowledge is addressed in an integrated way in the unit standard:
 Understanding and interpreting of physics terms.
 Understanding and interpreting of fluid flow dynamics.
 Manipulating basic mathematical relationships.
 Understanding the transfer of fluid power to mechanical power.
3.
TERMINOLOGY
The terminology used in this unit standard is consistent with generic engineering practices.
4.
NOTES TO ASSESSORS
Assessors should keep the following principles in mind when designing and conducting
assessments against this unit standard:
 Focus the assessment activities on gathering evidence in terms of the main outcome
expressed in the title to ensure assessment is integrated rather than fragmented.
Remember we want to declare the person competent in terms of the title. Where
assessment at title level is unmanageable, then focus assessment around each specific
outcome, or groups of specific outcomes.
 Make sure evidence is gathered across the entire range, wherever it applies.
Assessment activities should be as close to the real performance as possible, and
where simulations or role-plays are used, there should be supporting evidence to show
the candidate is able to perform in the real situation.
 Do not focus the assessment activities on each assessment criterion. Rather make sure
the assessment activities focus on outcomes and are sufficient to enable evidence to be
gathered around all the assessment criteria.
 The assessment criteria provide the specifications against which assessment
judgements should be made. In most cases, knowledge can be inferred from the quality
of the performances, but in other cases, knowledge and understanding will have to be
4
tested through questioning techniques. Where this is required, there will be assessment
criteria to specify the standard required.
 The task of the assessor is to gather sufficient evidence, of the prescribed type and
quality, as specified in this unit standard, that the candidate can achieve the outcomes
again and again and again. This means assessors will have to judge how many repeat
performances are required before they believe the performance is reproducible.
 All assessments should be conducted in line with the following well documented
principles of assessment: appropriateness, fairness, manageability, integration into work
or learning, validity, direct, authentic, sufficient, systematic, open and consistent
5