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Connect, test, and purge a service in a gas distribution network
Level
3
Credits
8
Purpose
People credited with this unit standard are able to: locate and identify
procedures, documentation, and equipment to connect, test, and purge a gas
service; prepare to connect, test, and purge a gas service; connect a gas
service to a gas main; carry out pneumatic pressure test on a gas service;
liven up and purge a gas service; reinstate site; and complete reporting and
documentation.
Subfield
Gas Industry
Domain
Gas Network Construction
Status
Registered
Status date
21 May 2010
Date version published
21 May 2010
Planned review date
31 December 2015
Entry information
Prerequisite: National Certificate in Gas Industry (Gas
Distribution) (Level 2) [Ref: 1020], or demonstrate
equivalent knowledge and skills.
Replacement information
This unit standard replaced unit standard 10973.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
NZ Motor Industry Training Organisation (Incorporated)
(MITO)
Accreditation and Moderation Action Plan (AMAP) reference
0114
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special notes
1
This unit standard is intended for, but is not limited to, workplace assessment. The
range statements relate to enterprise specific equipment, procedures, and
processes.
2
The current version of the following documents must be complied with:
Health and Safety in Employment Act 1992;
NZS 5258:2003 Gas distribution networks available at http://www.standards.co.nz.
 New Zealand Qualifications Authority 2016
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3
All work practices must comply with regulations and codes pertaining to the gas
industry. A full list of applicable regulations and codes is available from the NZ Motor
Industry Training Organisation (Incorporated) (MITO).
4
It is recommended that candidates are able to use a gas detector or have credit for
Unit 12507, Use gas leakage detection equipment on reticulated gas networks prior
to being assessed in this unit standard.
5
This unit standard relates to polyethylene pipe services and pneumatic pressure
testing in a gas distribution network.
6
Definition
Company procedures means the documented methods for performing work activities
and include health and safety, environmental, and quality management requirements.
They may refer to manuals, codes of practice, or policy statements.
Elements and performance criteria
Element 1
Locate and identify procedures, documentation, and equipment to connect, test, and purge
a gas service.
Performance criteria
1.1
Company procedures for testing and purging a gas service are located and
interpreted in relation to specified job requirements.
1.2
Job instructions are confirmed in accordance with company procedures.
Range
instructions include – site location, utility plans and/or mark-outs,
consents, easements.
1.3
Potential environmental and safety hazards are identified in accordance with
company procedures.
1.4
Methods of connecting polyethylene services to types of gas mains are
described in accordance with company procedures.
Range
1.5
methods may include but are not limited to – jointing, mechanical
couplings, steel welding;
drill and tap types may include but are not limited to –
polyethylene, cast iron, low pressure steel, medium pressure
steel, inserted main.
Methods of breaking into the casing pipe where there is an inserted gas main
are described in accordance with company procedures.
Range
may include but is not limited to – wheel cutters, window cutters,
cast iron cutters, exploratory drill hole.
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1.6
Pneumatic pressure testing and purging equipment, components, and materials
are identified and described in terms of type and function.
Range
equipment may include – gauge, compressor, test head, leak
detection equipment, purge stack, flare stack, gas detection
equipment, tools, fittings.
1.7
Equipment is described in terms of potential hazards of incorrect application
and operation, and the steps to avoid them are described in accordance with
company procedures.
1.8
Resource requirements are identified and sourced in accordance with company
procedures.
Range
plant, tools, materials, documentation, system components,
personnel, communication equipment.
Element 2
Prepare to connect, test, and purge a gas service.
Performance criteria
2.1
Safety and environmental hazards are identified, then isolated, removed, or
minimised, in accordance with company procedures.
Range
may include – signage, barriers, personal protective equipment,
safe access and egress, gas escape, fire, explosion, asphyxiation,
other utilities, temporary traffic control, environmental protection,
excavations.
2.2
Testing and purging equipment is prepared and positioned in accordance with
company procedures and manufacturer’s instructions.
2.3
Preparation ensures that pipe work and fittings are anchored in position, pipe
systems are isolated, air vents and drainage points are positioned according to
design and company requirements.
Element 3
Connect a gas service to a gas main.
Performance criteria
3.1
Type of gas main is prepared for connection in accordance with company
procedures.
Range
type may include but is not limited to – polyethylene, cast iron, low
pressure steel, medium pressure steel, inserted main.
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3.2
Gas service is connected in accordance with company procedures.
Range
3.3
may include but is not limited to – electrofusion jointing,
mechanical couplings, steel welding, drill and tap.
Where necessary, carrier pipe is protected from and sealed to casing pipe in
accordance with company procedures.
Range
anti-shear sleeve, sealing foam, denso/petrolatum tape,
polyvinylchloride tape.
Element 4
Carry out pneumatic pressure test on a gas service.
Performance criteria
4.1
Pneumatic test pressure is raised, and pressure level and security of pipe
system are monitored in accordance with company procedures.
4.2
Test equipment and pipe joints are tested for soundness in accordance with
company procedures.
4.3
Stabilisation period is timed in accordance with company procedures.
4.4
Atmospheric pressure reading is obtained in accordance with company
procedures.
4.5
Test period is timed, and pressure and time readings are recorded in
accordance with company procedures.
Range
initial readings, final readings.
4.6
Where test results show a pressure loss, leaks are traced and repaired, and retesting is completed in accordance with company procedures.
4.7
On completion of the test, pipe is depressurised in a controlled manner and test
equipment is disconnected in accordance with company and manufacturer's
recommendations.
4.8
Record of test is completed in accordance with company procedures.
Element 5
Liven up and purge a gas service.
Performance criteria
5.1
Gas service is livened up in accordance with company procedures.
Range
may include but is not limited to – puncture, tap, drill, squeeze off.
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5.2
Purging equipment is assembled and positioned in accordance with company
procedures.
Range
may include – purge stack, flare stack, continuity bond, gas
detector, fire extinguisher.
5.3
Equipment and pipe are pressurised and checked for soundness in accordance
with company procedures.
5.4
Leaks and damaged items are identified, are repaired or replaced, and are
reported in accordance with company procedures.
5.5
Purging is carried out in accordance with company procedures.
5.6
Unacceptable pressure conditions are identified and appropriate actions taken
in accordance with company procedures.
5.7
Specified gas concentration is achieved at all vent pipes in accordance with
company procedures.
5.8
Purging equipment is depressurised and disconnected in accordance with
company procedures.
Element 6
Reinstate site.
Performance criteria
6.1
Equipment and materials left temporarily on site are stored safely and securely,
or arrangements are made for their collection in accordance with company
procedures.
6.2
Tools, equipment, and materials are removed from site in accordance with job
requirements and company procedures.
6.3
Worksite is reinstated and made safe in accordance with company procedures.
Element 7
Complete reporting and documentation.
Performance criteria
7.1
Information is communicated to other parties, both internal and external, in
accordance with company procedures.
Range
may include but is not limited to – special conditions, completion
notice, additional work.
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7.2
Records and documents are completed and processed in accordance with
company procedures.
Range
may include but is not limited to – job card, test sheets.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP 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.
Comments on this unit standard
Please contact the NZ Motor Industry Training Organisation (Incorporated) (MITO)
info@mito.org.nz if you wish to suggest changes to the content of this unit standard.
 New Zealand Qualifications Authority 2016