Pigging and inspection tools

Pigging in oil and gas means passing a device called a pig through a pipeline to clean it, move liquids or inspect its condition. The selected tool determines the task; a cleaning pig does not provide the measurements of an instrumented inspection tool.

Typical applications

Pipeline preparation and maintenance can involve removing construction debris, displacing water or clearing accumulated liquids. Integrity programmes use inspection tools to collect specified condition data. Each application needs a tool matched to the line and its operating conditions.

Types and configuration choices

Foam, cup and disc pigs can serve utility duties, while instrumented tools collect selected measurements. Pipeline bore, bends, restrictions and launch-and-receive arrangements affect suitability. Define the objective before selecting the tool or requesting a quotation.

What is the difference between cleaning, gauging and inspection pigs?

Cleaning pigs address deposits or unwanted material in the line. A gauging pig checks passage against a specified bore requirement; it is not a complete wall-condition survey. Instrumented inline inspection tools collect data for defined inspection objectives. The enquiry should identify the required result and evidence, rather than treating every pig as an inspection gauge.

For example, a request to clear accumulated liquids and a request to locate metal loss describe different jobs. Ask a proposal to identify the tool's function and deliverables explicitly. A successful cleaning run alone is not evidence that a pipeline has passed an integrity assessment.

Can every pipeline use the same pig?

No. Changes in internal diameter, tight bends and access limitations can prevent a conventional tool from passing through a line. Provide current pipeline drawings and identify known restrictions. Piggability and tool compatibility require review for the actual pipeline; nominal pipe diameter alone is insufficient.

What should a pigging equipment enquiry include?

Send Oillinko the task, pipeline geometry, medium and operating envelope, available launch-and-receive facilities and required deliverables. Separate tools-only supply from an executed service. For an inspection assignment, identify the detection objective, data-analysis scope and reporting responsibilities. Ask for assumptions and exclusions to be listed against the same enquiry so that quotations can be compared consistently.

Pipeline ID and length

Physical interfaces determine whether an item can be integrated into the installation. Drawings should identify the relevant dimensions, mating connections, access limits and drawing revision. Nominal sizes do not always describe actual clearances or connection geometry, so include the governing dimensional reference where available. For replacements, photographs can help identify the assembly, but an approved drawing or exact part reference is preferable for critical interfaces. Record any installation constraints that could affect assembly, maintenance access or the scope of associated fittings and supports.

Bends and restrictions

The specification should establish a clear baseline for technical review. Record the required characteristics using the current design documents and identify any mandatory limits. If an input is provisional, label it as an assumption so the reviewer can explain its effect on the proposed solution. For existing assets, compare the current duty with the original design basis. Changes in conditions, interfaces or project requirements can mean that a previously accepted configuration needs a fresh compatibility assessment before it is purchased or used again.

Medium and operating pressure

The properties of the handled or measured material affect compatibility and performance. A name such as oil, gas or water can cover very different compositions, temperatures and contamination levels. Use the available analysis or approved material specification to describe the actual duty. Identify expected variation and distinguish measured data from estimates. For replacements, record whether the medium or operating conditions have changed since the existing equipment was selected. These details help a reviewer assess a proposed material or configuration against the intended application.

Cleaning or inspection objective

The required evidence should relate to the actual purpose of the item or assignment. Identify the method, acceptance basis and documents required by the project, including the relevant edition or revision where specified. A certificate title alone may not establish that the required scope or measurement range is covered. Distinguish manufacturer records, calibration results, inspection reports and specialist qualifications. State whether witnessing or independent review is required, and make the responsibility for evaluating the results clear before comparing technical and commercial proposals.

How related requirements differ

Hot tapping and line stopping: Hot-tapping equipment supports an engineered connection to an existing pressurized line. Line-stopping equipment provides a specified temporary isolation arrangement. These are specialist pipeline-intervention functions governed by a project-specific design and work programme. Fittings, machines, cutters and isolation components must form a compatible system. State pipe data and the intervention objective; a catalogue listing is not an execution procedure.

Repair clamps and isolation plugs: Repair clamps enclose or reinforce a defined area of piping according to a selected repair design. Isolation plugs provide temporary isolation for specified systems. Their operating duties and qualification requirements differ. Diameter, wall thickness, material, pressure and medium are essential inputs. Permanent repair components and temporary isolation tools require separately documented responsibilities and acceptance requirements.

Leak detection and corrosion monitoring: Leak-detection systems identify signals associated with potential loss of containment, while corrosion monitoring tracks selected indicators of material degradation. The technologies produce different information for the asset-integrity programme. Sensors, probes, coupons and software-based systems have distinct interfaces. Specify measurement targets, communication requirements, installation conditions and interpretation or reporting scope.

Compare the complete supply scope

For pigging and inspection tools, compare the complete assembly and documented scope of supply. An offer for a component may exclude the drive, controls, fittings, accessories or inspection services needed for the installation. List exclusions and proposed alternatives so each quotation can be assessed against the same requirement. Manufacturing origin, delivery location and the supplier's business address are separate facts. If a particular origin is required, request confirmation for the actual offered item and the supporting documentation specified by your project.

Questions before requesting a quotation

What information should be available first? Start with the intended application and the current technical specification for pigging and inspection tools. In this category, the initial review includes pipeline id and length, bends and restrictions, medium and operating pressure, cleaning or inspection objective. Attach the relevant drawings or scope documents and identify any information still awaiting confirmation. This makes it possible to distinguish a preliminary enquiry from a fully defined purchasing or service requirement.

Can an alternative be accepted on size or price alone? A proposed alternative needs review against the required function, materials, interfaces and documented performance. Similar dimensions or a familiar brand name do not establish compatibility. State which requirements are mandatory and where an equivalent may be considered. Availability, lead time and supporting documents are confirmed for the actual offer rather than assumed from this catalogue.