NZQA Expiring unit standard
25139 version 2
Page 1 of 4
Title
Demonstrate knowledge of pumps and motors, and their selection,
for irrigation systems
Level
5
Credits
Purpose
15
This unit standard is for people who design irrigation systems.
People credited with this unit standard are able to: demonstrate
knowledge of the characteristics of pumps and motors;
demonstrate knowledge of affinity laws, and their effect on
pump performance; calculate Net Positive Suction Head
(NPSH), describe factors causing cavitation, and check NPSH
available against NPSH required, in accordance with the
Irrigation Design Code of Practice; and describe the selection
criteria, and calculate capital and annualised operating costs,
for pump and motor combinations for irrigation systems.
Classification
Water Industry > Irrigation
Available grade
Achieved
Explanatory notes
1
Legislation, regulations, and guidelines relevant to this unit standard include but are
not limited to the Health Act 1956, Health and Safety in Employment Act 1992,
Building Act 2004, Resource Management Act 1991, national policy statements,
regional resource management plans, and local bylaws.
2
Reference
The INZ Irrigation Design Code of Practice and Irrigation Design Standards, referred
to as the Irrigation Design Code of Practice is available from Irrigation New Zealand,
http://www.irrigationnz.co.nz/media/CoP.pdf.
3
Credit for this unit standard does not qualify the candidate to work in a drainlaying
situation that comes under the drainlayers licence requirements issued under the
Plumber, Gasfitters, and Drainlayers Act 2006 and any subsequent amendments.
This unit standard is
expiring
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
25139 version 2
Page 2 of 4
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of the characteristics of pumps and motors.
Range
pumps – centrifugal, positive displacement;
motors – electric, internal combustion.
Evidence requirements
1.1
Pumps are described in terms of duties, suction limits, power, efficiency, and
performance.
1.2
Motors are described in terms of their power, efficiency, energy or fuel
consumption, control method, and speed.
Range
fixed speed, variable speed.
Outcome 2
Demonstrate knowledge of affinity laws, and their effect on pump performance.
Evidence requirements
2.1
The relationship between pressure, flow, power, speed, and impellor diameter is
described.
2.2
Pressure, flow, power, speed, and impellor diameter are described in terms of
their effect on pump performance and efficiency.
This unit standard is
Calculate Net Positive Suction Head (NPSH), describe factors causing cavitation, and
check NPSH available against NPSH
required, in accordance with the Irrigation Design
expiring
Code of Practice.
Outcome 3
Evidence requirements
3.1
NPSH is calculated.
Range
head, friction loss, atmospheric pressure, vapour pressure, safety
factor.
3.2
Factors causing cavitation are described.
3.3
The procedures for pump checking and adjustments to ensure that NPSH
available is greater than NPSH are described.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
25139 version 2
Page 3 of 4
Outcome 4
Describe the selection criteria, and calculate capital and annualised operating costs, for
pump and motor combinations for irrigation systems.
Range
direct drive diesel, surface electric, submersible.
Evidence requirements
4.1
The selection criteria for pump and motor combinations are described for a
range of operating conditions.
Range
4.2
flow head, efficiency, duty points, water quality, power, energy
source, variable speed.
The capital cost and annualised operating cost of pump and motor
combinations are calculated.
Replacement information
This unit standard and unit standards 25140, 25141,
25135, 20956 have been replaced by unit standard
28932
This unit standard is expiring. Assessment against the standard must take place by
the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
This
unit
standard
is2020
2
20
August 2015
31 December
Consent and Moderation Requirements
(CMR) reference
0179
expiring
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Registration
1
17 October 2008
31 December 2020
Review
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
25139 version 2
Page 4 of 4
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
This unit standard is
expiring
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016