NZQA Expiring unit standard
25140 version 2
Page 1 of 4
Title
Determine irrigation system hydraulic gradeline, surge implications,
and performance, and describe speciality valves
Level
5
Purpose
Credits
15
This unit standard is for people who design irrigation systems.
People credited with this unit standard are able to: calculate the
hydraulic gradeline for a pipeline system; carry out surge
analysis for an irrigation pipeline system; perform an irrigation
system performance analysis; and describe the operation and
function of speciality valves, determine their requirement in
irrigation pipeline systems, and their influence on hydraulic
gradeline.
Classification
Water Industry > Irrigation
Available grade
Achieved
Explanatory notes
1
Legislation relevant to this unit standard includes but is not limited to the Health and
Safety in Employment Act 1992.
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
4
This unit standard is
Assessment
expiring
Calculations used for assessment
against element 1 should be used for element 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.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
25140 version 2
Page 2 of 4
Outcomes and evidence requirements
Outcome 1
Calculate the hydraulic gradeline for a pipeline system.
Evidence requirements
1.1
Pressure change resulting from elevation, and flow in pipes in the pipeline
system, are calculated.
Range
1.2
Pressure loss across components is determined.
Range
1.3
friction loss, turbulent flow, laminar flow, uniform flow, uniformly
decreasing flow, non-uniformly decreasing flow, looped networks,
roughness.
K-factor, equivalent pipe lengths, interpretation of manufacturer’s
data;
components include but are not limited to – fittings, valves, filters,
injectors.
Hydraulic gradeline is plotted and interpreted, and maximum and minimum
pressure is determined.
Range
ground profile, pressure profile, outlet pressure requirement.
Outcome 2
Carry out surge analysis for an irrigation pipeline system.
This unit standard is
Velocity and magnitude of pressure wave are determined for the irrigation
system.
expiring
Evidence requirements
2.1
Range
2.2
The implications of surge are described in terms of the irrigation pipeline
system.
Range
2.3
water velocity, water pressure, rate of valve closure, pump
shutdown and start, pipeline types.
component risk, system risk.
Mitigation measures are described for identified risks.
Outcome 3
Perform an irrigation system performance analysis.
Evidence requirements
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
3.1
25140 version 2
Page 3 of 4
System performance is plotted against the pump performance curve.
Range
effect of change of flow on pressure, duty changes.
Outcome 4
Describe the operation and function of speciality valves, and determine their requirement
in irrigation pipeline systems and their influence on hydraulic gradeline.
Range
valves include but are not limited to – air relief, vacuum relief, combination,
pressure relief, pressure regulating, pressure sustaining, backflow prevention.
Evidence requirements
4.1
Valves are described in terms of their operation, influence on hydraulic
gradeline, and function in pipeline systems.
4.2
The irrigation pipeline system is analysed for the requirement for valves.
Replacement information
This unit standard and unit standards 25139, 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
Registration
Review
This
unit standard
is
1
17 October 2008
31 December 2020
2
20 August 2015
expiring 31 December 2020
Consent and Moderation Requirements (CMR) reference
0179
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
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.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
25140 version 2
Page 4 of 4
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
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