Pipeline Integrity Management in Australia: What Operators Need to Know

1. What Is Pipeline Integrity Management?

Pipeline integrity management is the disciplined, systematic process of ensuring that a pipeline remains fit for purpose — safe, reliable, and compliant — throughout its operational life. It encompasses everything from the initial identification of threats during design through to monitoring, inspection, maintenance, and ultimately decommissioning.
For Australian pipeline operators, integrity management is not optional — it is a regulatory requirement. Gas and liquid petroleum pipelines operating under AS 2885 must have a documented and maintained Pipeline Integrity Management Plan (PIMP) that identifies all credible threats to the pipeline, assesses their risk, and specifies the inspection and maintenance activities required to manage those threats to an acceptable level.
Pigging is one of the primary tools of pipeline integrity management — both for maintenance (cleaning pigs that remove corrosion-promoting deposits and restore flow efficiency) and for inspection (intelligent inline inspection pigs that detect and map internal defects and anomalies). Understanding how pigging fits into the broader integrity management framework is essential for pipeline operators, asset managers, and maintenance engineers across Australia.

Australian pipeline network

Australia has more than 40,000 km of transmission pipelines transporting natural gas, crude oil, and refined products, plus extensive distribution networks in all major cities. Western Australia alone has over 15,000 km of gas transmission pipelines — the most extensive network of any Australian state — and a growing number of water transmission mains operated by Water Corporation WA and local water utilities. All of these pipelines require ongoing integrity management programs.

2. The Regulatory Framework in Australia

Australian pipeline integrity management is governed by a combination of national standards, state legislation, and industry codes. The key regulatory instruments are:

AS 2885 — Pipelines: Gas and Liquid Petroleum

AS 2885 is the primary Australian standard for the design, construction, operation, and maintenance of high-pressure gas and liquid petroleum pipelines. It is a suite of standards:

AS 2885.3 contains the specific requirements for Pipeline Integrity Management Plans, inspection programs, maintenance activities, and the documentation required for regulatory compliance. It is the standard that pipeline operators reference when planning their pigging programs.

State pipeline safety legislation

In addition to AS 2885, pipeline operators must comply with state pipeline safety legislation. In Western Australia, this is the Petroleum Pipelines Act 1969 and the Energy Safety Regulations. In Queensland, the Gas Supply Act 2003. In New South Wales, the Gas Supply Act 1996 and Pipeline Act 1967. In South Australia, the Petroleum and Geothermal Energy Act 2000. State safety regulators — including the Energy Safety Regulator in WA — oversee compliance with both state legislation and AS 2885 requirements.

Water pipeline standards

Water transmission mains and distribution pipelines are not governed by AS 2885 — they fall under state water authority standards and guidelines issued by the relevant water corporation (Water Corporation WA, Sydney Water, Melbourne Water, SA Water, etc.). These standards typically reference Australian Drinking Water Guidelines (ADWG) for water quality and specify inspection, flushing, and cleaning requirements for water mains.

★ Regulatory compliance note

Failure to maintain a current and compliant PIMP is an offence under AS 2885 and the relevant state pipeline safety legislation. In the event of a pipeline incident, a regulator’s first inquiry will be whether the operator had a current PIMP and whether the inspection and maintenance activities specified in it had been carried out. Royal Poly Products’ pigging records — pig run logs, receiver inspection reports, debris assessments — are designed to support PIMP documentation requirements.

3. What Is a Pipeline Integrity Management Plan (PIMP)?

A Pipeline Integrity Management Plan (PIMP) is the central document of an Australian pipeline operator’s integrity program. Required under AS 2885.3, a PIMP documents all threats to pipeline integrity, the risk assessment for each threat, and the specific inspection, monitoring, and maintenance activities the operator will carry out to manage those threats.
A PIMP must be reviewed and updated at regular intervals — typically every 5 years, or sooner if a significant change occurs (such as a pipeline modification, a change in operating conditions, or an integrity incident). The following table summarises the key elements of an AS 2885.3-compliant PIMP and how pigging relates to each element:

Every element of the PIMP has implications for the pigging program. The threat identification element determines where cleaning pigs are needed. The inspection element drives the ILI schedule and associated pre-ILI cleaning pig runs. The preventive measures element may include corrosion inhibitor gel pig programs. The records element requires documentation of all pig runs.

4. The Role of Pigging in Pipeline Integrity

Pipeline pigging plays three distinct roles in an integrity management program:

Maintenance pigging — preventing integrity threats

Regular cleaning pig runs remove internal corrosion products, wax, silt, scale, and biofilm from the pipeline bore. These deposits — if left unchecked — accelerate internal corrosion, reduce flow efficiency, and create the conditions for microbiologically influenced corrosion (MIC). A scheduled maintenance pigging program is one of the most cost-effective tools for preventing internal corrosion threats from developing.
In gas transmission pipelines, regular cleaning pig runs also remove liquid accumulation — water and hydrocarbon condensate — that collects at low points in the pipeline profile. Liquid accumulation causes severe localised corrosion at the 6 o’clock position of the pipe and is one of the leading causes of internal corrosion failures in Australian gas pipelines.

Pre-ILI preparation pigging — enabling inspection

Before an intelligent inline inspection pig (ILI tool or smart pig) is deployed, the pipeline must be cleaned to a standard that allows the inspection tool to travel safely and its sensors to function accurately. Debris, scale, wax, and internal deposits that remain on the pipe wall after inadequate cleaning interfere with the sensor signals, reduce data quality, and may damage the ILI tool.
Pre-ILI cleaning typically involves a sequence of progressively more aggressive foam pig runs — starting with medium density criss-cross pigs (MD-XX) and potentially escalating to silicon carbide or wire brush pigs — followed by a gauging pig run to confirm the bore is clear before the ILI tool is deployed. Royal Poly Products has supplied pre-ILI cleaning pigs for dozens of Australian pipeline integrity campaigns.

Post-inspection pigging — responding to findings

After an ILI campaign, the inspection data is analysed and anomalies are classified by severity. Where anomalies indicate accelerating internal corrosion, increased cleaning pig frequency may be specified as an immediate response — to remove the corrosion-promoting deposits that are driving the anomaly progression. In some cases, a corrosion inhibitor gel pig program is initiated to passivate the internal surface and reduce corrosion rates while longer-term remediation is planned.

★ Key point

The most common reason Australian pipeline operators call Royal Poly Products is pre-ILI cleaning. A pipeline that is not cleaned adequately before an ILI run will either fail the cleanliness check performed by the ILI vendor before tool deployment — causing costly mobilisation delays — or will produce poor-quality data that requires a re-run. The cost of a pre-ILI cleaning program is always a fraction of the cost of an aborted or repeated ILI campaign.

5. Inline Inspection (ILI) Technologies

Inline inspection tools — also called smart pigs or ILI tools — are the primary technology for detecting and mapping internal defects in Australian pipelines. The following table summarises the main ILI technologies used in Australia and their pre-cleaning requirements:

The choice of ILI technology is driven by the threats being assessed, the pipeline product (gas vs liquid), and the pipeline geometry. Most Australian gas pipeline ILI campaigns use MFL tools for general corrosion detection, with caliper/geometry tools typically run first to confirm bore clearance. For pipelines with a stress corrosion cracking risk, EMAT tools are increasingly used.

★ Royal Poly Products and ILI

Royal Poly Products does not manufacture ILI tools — these are supplied by specialist inspection contractors. However, Royal Poly Products provides the pre-ILI cleaning pig sequences and gauging pig services that prepare the pipeline for the ILI run. The company works with major ILI vendors and pipeline operators across Australia to ensure the pipeline is in the correct condition for tool deployment.

6. Pre-ILI Cleaning — Why It Matters

Pre-ILI cleaning is the pigging sequence performed on a pipeline before an ILI tool is deployed. It is one of the most important — and most frequently underestimated — activities in a pipeline integrity program. The consequences of inadequate pre-ILI cleaning are:

Tool damage and mobilisation cost

An ILI tool travelling through a pipeline with significant internal debris can be physically damaged — sensors abraded, brush contacts blocked, electronics contaminated. ILI tools are expensive — a single MFL tool run costs $200,000–$1,000,000 or more depending on pipeline diameter and length. A damaged tool may require withdrawal, repair or replacement, and remobilisation, multiplying the campaign cost.

Poor data quality

Even if the ILI tool is not physically damaged, debris on the pipe wall between the tool’s sensors and the pipe surface degrades signal quality. MFL tools require close magnetic contact with the pipe wall — a layer of scale, wax, or debris between the magnetiser and the pipe surface reduces the magnetic flux leakage signal and may mask genuine metal loss anomalies. The result is a data set with higher uncertainty, more calls for investigation, and potentially missed defects.

Tool stuck or stopped

A significant debris accumulation can cause an ILI tool to stall in the pipeline — particularly in small-diameter pipelines where the bore-to-tool clearance is tight. A stuck ILI tool is one of the most serious and costly incidents in pipeline operations — recovery may require excavation and pipeline section removal.

The standard pre-ILI cleaning sequence for an Australian gas pipeline typically involves:

★ILI vendor cleanliness specifications

Major ILI vendors (TDW, Baker Hughes, Rosen, Applus RTD) specify minimum cleanliness standards that must be met before their tools are deployed. These specifications typically reference API 1163 or similar standards and require the operator to demonstrate — through pig run records and receiver inspection reports — that the pipeline has been cleaned to the required standard. Royal Poly Products’ pig run documentation is designed to meet these vendor requirements.

7. Routine Maintenance Pigging Frequency

The frequency of routine maintenance pigging is specified in the operator’s PIMP and is based on the threat assessment for the pipeline. The following table provides typical maintenance pigging frequencies for common Australian pipeline types — these are indicative figures only and the actual frequency for any specific pipeline must be determined by the operator’s threat assessment:

These frequencies may be adjusted based on:

★ Documenting pigging frequency in your PIMP

The pigging frequency specified in your PIMP must be supported by the threat assessment. A frequency that is lower than the industry norm for your pipeline type requires specific justification in the PIMP — for example, demonstrated low internal corrosion rates from multiple ILI campaigns, low liquid content in a gas pipeline, or a specific inhibitor program that reduces corrosion rates. Royal Poly Products can advise on appropriate pigging frequencies for your pipeline type and condition.

8. Pipeline Integrity for Water Utilities

Water transmission mains and distribution pipelines in Australia face different integrity challenges from gas and oil pipelines, but pigging plays an equally important role in maintaining their integrity and service performance.

Internal corrosion in water mains

Cast iron and ductile iron water mains — which make up a large proportion of Australia’s urban water distribution networks — are subject to internal tuberculation: the build-up of iron corrosion products and mineral deposits on the pipe wall. Tuberculation reduces the effective bore diameter, increases head loss, and affects water quality. Regular foam pig cleaning removes tuberculation and restores hydraulic capacity.

Biofilm and microbiological issues

Water mains provide ideal conditions for biofilm formation — a thin layer of microorganisms that colonises the pipe wall and can degrade water quality, cause taste and odour issues, and in severe cases, contribute to microbiologically influenced corrosion. Regular cleaning pig runs disrupt and remove biofilm, and biocide gel pig sequences can deliver targeted treatment to the full bore surface.

Sedimentation in water transmission mains

Large-diameter water transmission mains — particularly those carrying raw or partially treated water — accumulate sediment at low points in the pipeline profile. This sediment reduces flow capacity and can cause turbidity events when hydraulic conditions change (such as during demand peaks or valve operations). Regular pigging removes accumulated sediment and maintains the transmission main’s design flow capacity.

Pre-commissioning and rehabilitation pigging

When existing water mains are rehabilitated — relined with cement mortar, epoxy, or PE — pigging is used before lining to clean the bore, and after lining to remove excess lining material and check the finished bore dimensions. Royal Poly Products’ foam pigs and disc pigs are used for water main rehabilitation pigging across Australian water utilities.

★ Potable water compliance

All foam pigs and pipeline gels used in potable water pipelines must be manufactured from materials that comply with relevant Australian drinking water standards and are certified for food-grade or drinking-water contact. Royal Poly Products can supply pigs and gels with the appropriate material certifications for potable water pipeline applications. Always specify the intended pipeline product when ordering pigs for water utility projects.

9. Common Integrity Management Mistakes

Treating PIMP preparation as a one-time exercise

A PIMP that is prepared for initial regulatory approval and then not updated is a compliance liability and an operational risk. Pipeline conditions change — operating pressure, product composition, corrosion rates, and external loading all evolve over time. A PIMP must be a living document, reviewed and updated at the intervals specified in AS 2885.3 and whenever a significant change occurs.

Underestimating pre-ILI cleaning requirements

The most common — and most costly — mistake in pipeline integrity programs. Operators who allocate insufficient time and budget for pre-ILI cleaning frequently encounter ILI tool deployment rejections or poor data quality that requires additional cleaning runs. Pre-ILI cleaning should be planned as a multi-run sequence, not a single pig run. Budget and schedule for 3–5 cleaning pig runs before the ILI tool is mobilised.

Not recording pig run data

Pig run data — launch time, signaler passage times, receiver arrival, pig condition, debris volume and type — is required under AS 2885.3 as part of the integrity program records. Operators who do not record this data cannot demonstrate to regulators that their pigging program has been carried out as specified in the PIMP. Establish a standard pig run data sheet and complete it for every pig run.

Reducing pigging frequency without justification

Reducing the cleaning pig frequency below the PIMP-specified interval to save cost is a common and dangerous practice. If an internal corrosion anomaly is subsequently found at an ILI inspection and the cleaning log shows pigs were not run at the specified frequency, the operator faces both a regulatory compliance issue and a potential liability question about whether more frequent cleaning would have prevented the anomaly from developing. Any change to PIMP-specified activities requires a formal risk assessment and PIMP update.