Pipeline Pre-Commissioning & Cleaning SWMS
Pipeline pre-commissioning — flooding, cleaning pig runs, dewatering, drying with desiccant or vacuum. Confined-space risk where tie-in points open. Stored-energy from compressed-air drying.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Pipeline pre-commissioning involves flooding, cleaning pig runs, dewatering and drying via desiccant or vacuum methods. Tie-in openings create confined space exposure while compressed-air drying introduces stored pneumatic energy. WHS Regulation 2025 mandates documented SWMS before commencing this high-risk construction work on pressurised pipelines.
Hazards identified
3 hazards covered, sorted by priority.
Catastrophic rupture, pig ejection, fatal projectile impact
Asphyxiation from oxygen displacement or residual hydrocarbons
Environmental harm, slip injuries, chemical exposure
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Establish exclusion zones per AS/NZS 2885.5 with calculated stored-energy radii before pigging or pressure release.
- 2Issue confined space permits, gas-test atmospheres continuously, and station trained standby attendant at every tie-in.
- 3Isolate, lock-out and depressurise per LOTO procedure; verify zero energy before any tie-in break-in.
Applicable Codes of Practice
Mandatory commissioning, testing and stored-energy controls
Tie-in entries meet confined space definition
High-Risk Construction Work triggered
Pre-commissioning directly involves pressurising and depressurising gas pipeline systems.
Cleaning and dewatering hydrocarbon or chemical product pipelines during commissioning phase.
SWMS mandatory before work starts; PCBU faces prosecution if absent.
Who this is for
- →Pipeline pre-commissioning crews performing flooding, cleaning, dewatering, and drying of completed lines.
- →SME pipeline contractors delivering cleaning-pig and drying scopes before commissioning.
- →Mid-tier pipeline contractors managing pre-commissioning and stored-energy operations.
- →Pipeline operators and principal contractors requiring a defensible pre-commissioning SWMS.
- →EHS and process-safety compliance leads responsible for stored-energy, confined-space, and compressed-air-drying controls.
What you receive
- ✓Editable DOCX SWMS customisable to project and pipeline specification
- ✓State-specific WHS legislation schedule (NSW, VIC, QLD, WA, SA, TAS, NT, ACT)
- ✓Pipeline pre-commissioning hazard register with risk matrix
- ✓Worker sign-on register for SWMS consultation evidence
Worked example
A pipeline contractor pre-commissions a completed section of gas transmission pipeline in regional Queensland, running cleaning pigs, dewatering after the hydrotest, and drying the line with compressed air and desiccant before it is handed over for commissioning. The pre-commissioning runs over two weeks. Before work, the contractor reviews the SWMS against the line: the cleaning-pig runs and the propelling-medium pressure are set, the dewatering and the disposal of the test and flush water are planned, and the stored energy of the compressed-air drying and the tie-in points that open as confined spaces are identified. The dominant hazards are the stored energy in the line during pig runs and compressed-air drying, the confined-space risk where tie-in points are opened, the handling and disposal of the dewatering and flush water, and the pig launching and receiving, so the SWMS specifies stored-energy management with exclusion zones during pressurised pig runs and compressed-air drying, confined-space entry to AS 2865 where tie-in points are opened, controlled handling and disposal of the dewatering and flush water, and a defined pig launching and receiving sequence with the barrels depressurised before opening. Personnel are kept clear of the line ends during the high-energy phases. The cleaning, dewatering, and drying are completed and the line dried to specification. The stored-energy, confined-space, and water-disposal records are documented, and the pre-commissioning is completed without a stored-energy release reaching personnel or a confined-space incident, with the records retained for the operator.
Related legislation
- WHS Act 2011 s.19 — primary duty of care
- WHS Regulation 2025 Part 6.4 — high risk construction work
- Pipelines Act (state-specific) — licensed pipeline operations
Frequently asked questions
Why is compressed-air drying a stored-energy hazard?
Drying the line with compressed air pressurises the pipeline with a compressible medium, which stores significant energy that can release violently if a component fails or a barrel is opened under pressure, so the SWMS specifies stored-energy management with exclusion zones during compressed-air drying and personnel kept clear of the line ends. Compressed gas stores more recoverable energy than water for the same pressure. Because a release during air drying is a high-energy event, the exclusion and crew-positioning controls are critical during that phase.
When does pre-commissioning involve confined-space work?
Where tie-in points or fittings are opened to insert or recover pigs or to connect sections, the opened pipeline or pit can be a confined space under AS 2865, with a restricted atmosphere, so the SWMS specifies confined-space entry to AS 2865 where tie-in points are opened, with atmospheric testing and the entry controls. The confined-space controls apply at those access points. Opening a pipeline section without confined-space controls where entry is required would expose workers to an uncontrolled atmosphere.
Why is pre-commissioning high-risk construction work?
It involves the stored energy of pressurised pig runs and compressed-air drying, confined-space entry at tie-in points, and the handling of dewatering and flush water, with several elements engaging the high-risk categories for pressurised systems and confined spaces. A stored-energy release or a confined-space atmosphere incident presents a serious hazard. A SWMS is required, with stored-energy management, confined-space controls, water handling, and a defined pig sequence as central elements.
How is the dewatering and flush water managed?
After the hydrotest and flushing, the line holds water that must be removed and disposed of, and the water can carry constituents from the line and the test, so the SWMS specifies controlled handling and disposal of the dewatering and flush water to the relevant requirements. The water is not discharged uncontrolled. Because the flush water can be an environmental issue and the volumes are significant, the SWMS includes the water handling and disposal alongside the stored-energy and confined-space controls.
How is this different from the hydrostatic-testing SWMS?
Hydrostatic testing pressurises the line with water to verify its integrity, where the dominant hazard is the stored energy of the test and the exclusion zones from the failure-consequence assessment. Pre-commissioning is the subsequent cleaning, dewatering, and drying to prepare the line for service, where the hazards shift to the pig runs, the compressed-air drying stored energy, confined-space tie-ins, and water disposal. The SWMS reflects the pre-commissioning activities, which follow and differ from the integrity test.