Pig signaler — Dual Type
Combines a mechanical flag with a digital electrical output for local and remote pig-passage confirmation.
Product overview · Dual Type
LINESIG Bi-Directional Pig Signalers are pipeline-mounted detection devices designed to provide positive indication when a pig passes through a pipeline in either direction.
The LINESIG Dual Bi-Directional Pig Signaler combines a conventional mechanical flag with an electrical/digital switching output.
When the pig passes the sensing point, the mechanism simultaneously operates the local mechanical flag and activates the electrical signal contact for remote indication — giving both field confirmation and centralized monitoring through PLC, SCADA, DCS, ESD or terminal automation systems.

Design
Technical specification
| Detection direction | Bi-directional |
|---|---|
| Pipeline size range | 4 in to 48 in |
| Maximum working pressure | Up to 25 bar |
| Temperature range | −20°C to +120°C |
| Wetted parts | SS316 |
| Installation | Pipeline / pig launcher / pig receiver |
| Detection principle | Intrusive mechanical trigger |
| Reset | Manual / project-specific |
| Process connection | Project / pipeline dependent |
| Hazardous area certification | Available subject to selected electrical configuration |
| Wetted trigger | SS316 |
|---|---|
| Wetted shaft | SS316 |
| Process sealing components | Service-compatible material |
| External housing | Carbon steel / stainless steel / project-specific |
| Flag | Corrosion-resistant metal |
| Fasteners | Stainless steel / project-specific |
How it works
Normal position: before pig passage, the intrusive trigger projects into the pipeline bore while the flag remains in its normal indication position.
Pig contact: as the pig passes, it contacts the sensing element. Because the mechanism is designed for bi-directional operation, pig movement from either upstream or downstream direction can actuate the device.
Indication: Pig Passage → Flag Changes Position + Electrical Contact Changes State
Reset: following confirmation of pig passage, the mechanism can be reset according to the selected design.
Digital output
Depending on the selected configuration, the digital section may provide:
Final output type must be defined in the electrical datasheet rather than assumed as universal across all versions.
The Dual Type can interface with PLC, SCADA, DCS, ESD, Terminal Automation Systems, Pipeline Monitoring Systems and Pig Tracking Systems. Typical status tags include:
Where it's used
Ordering information