A subsea PIG detector confirms one event: a PIG passed a known installation point. Its value in subsea PIG detection is a defensible checkpoint that can be related to the run record, rather than a continuous map of position or a judgement on whether the whole run met its objectives.
For pipeline run confirmation, time and place have to remain together. A timestamp without a durable point reference cannot be compared confidently with launch records or downstream observations. A detector tag without a reconciled time basis is equally difficult to use at handover.
Use the passage event as a checkpoint
The useful record is concise: run identity, detector reference and the passage indication. If the receiving control or logging system supplies a time, retain that timestamp and its time basis as a separate integration fact. The current subsea product evidence proves point-of-installation passage monitoring, not an onboard timestamp feature. A recorded passage at checkpoint B remains different from a conclusion that the PIG completed the run.
Think of a detector as a gate on a route. Crossing the gate confirms movement through that boundary, but it cannot describe every metre before or after it. Keeping that distinction clear prevents a precise instrument event from being stretched into an unsupported account of PIG location, speed or condition.
Build a sequence on one time basis
Before comparing an indication with an expected window, check that the detector, launch record and control record use compatible clocks and conventions. A real difference can matter. An unreconciled clock can also create a false difference that sends the review in the wrong direction.
Where several instrumented points are available, the record becomes a sequence: a PIG was indicated at point A and later at point B. The elapsed interval can then be compared with the run context, provided both references and timestamps are comparable. The interval remains an interval, not a trace of what happened between the two points.
Keep the event review disciplined
- Match the indication to the run identity and the named detector point.
- Confirm the timestamp basis before comparing records.
- Put the event beside the relevant upstream or downstream checkpoint.
- Record any remaining question without attaching an untested cause.
This is an information-review framework, not a pigging procedure. Operating windows, communications, response actions and run acceptance remain within authorised arrangements for the particular asset.
Let an absent event remain an information gap
If an expected indication is not recorded, the first accurate statement is narrow: passage was not confirmed at that point during the stated observation window. That observation does not establish why the record is absent, where the PIG is, or whether the cause lies with the detector, recording path, communications or run conditions.
Preserve the facts that can be checked: intended point, run identity, observation window, record availability and material operational context. The responsible people can then assess the gap against the wider run information. An honest uncertainty is more useful than a forced yes-or-no entry that later reviewers cannot defend.
Match the detector to the required point
The ClampOn DSP Subsea PIG Detector monitors PIG passage at its installation point and can be installed subsea to 3000 m. The manufacturer’s PIG detector range confirms the family role of registering and monitoring launch, arrival or passage at specific points. Subsea depth capability does not settle mounting, communication, output or integration choices for a named asset.
The point reference should be clear enough for operations, inspection and engineering teams to identify the same location later. Depending on the asset record, that may be an agreed tag, route reference, drawing reference or boundary name. A vague label can make an otherwise sound signal difficult to use after a shift change.
Where the confirmation point is accessible above water instead, the ClampOn DSP Topside PIG Detector provides the equivalent topside passage-monitoring pathway. Comparing these locations first is more useful than choosing a model by name alone.
Choose the evidence point before the product
The PIG detection options include topside and subsea detectors. The initial decision is the confirmation point the run record needs, followed by the conditions that apply there. Number of checkpoints, installation detail, integration and acceptance requirements are separate project decisions.
That order also helps avoid a common handover error. A detector may be perfectly suited to confirming passage at its own point while being irrelevant to an unanswered condition question elsewhere on the route. The record should name the question the event can answer, and leave other questions visible.
Keep the event intact through transfer
Subsea and topside passage points should never be treated as interchangeable. Once the installation environment is fixed, procure the corresponding ClampOn DSP PIG detector through Aquip and obtain product information for that named detector. Checkpoint identity, event time and any qualification must travel together in every run record.
A detector event then moves into the run record without acquiring a broader claim. Preserve the run identity and original checkpoint name beside the timestamp, and retain any qualification such as an uncertain window or unavailable indication.
When several events are consolidated, do not rename checkpoints or round away the sequence needed for reconciliation. A combined sequence should still point back to each detector record and show any point with no indication during the stated window. Passage at one checkpoint cannot fill a blank at another, and elapsed time between events should be interpreted only against the run information retained by the project.
Keep detection separate from the wider run outcome. A passage indication establishes an event at its own detection point; it does not establish cleaning effectiveness, inspection success or integrity elsewhere. Where the event is qualified, reproduce that qualification in summaries and downstream messages rather than leaving it only in the instrument record.
Use the same checkpoint identifier in the control-room entry, run file and shift communication so later reconciliation does not depend on informal location names.
Retain the stated observation window beside any absent indication.
The minimum that must survive every transfer is checkpoint identity, event time and its qualification.