Description

EMT is a pig signaller supplier offering the CGQ-1 non-intrusive indicator that detects, indicates, and records pig passage with IP66, explosion-proof housing, and 4-20mA output.

What Is a Pig Signaller?

A pig signaller is a detection device that confirms whether a pipeline pig has passed a given installation point during pigging operations. EMT builds the CGQ-1 as a non-intrusive unit that clamps to the pipe without cutting it open. It is installed at launcher and receiver stations and at key nodes where operators must confirm the pig has arrived. The device turns an invisible event inside the line into a visible, recorded signal.

Pipelines carry pigs for cleaning, batching, and in-line inspection. When a pig stalls at a bend or passes a critical tee, the signaller is the first alarm the control room receives. A dependable pig signaller supplier therefore protects both the asset and the schedule. Two families exist: intrusive units that penetrate the line, and non-intrusive units like the CGQ-1 that sense the pig from outside the pipe wall. For most brownfield tie-ins, the non-intrusive option avoids hot work and keeps the line in service. Operators rely on the signaller to verify each run and to confirm a pig has exited the receiver before opening the trap. A missed passage can mean a pig stuck for days, with downtime costing far more than the instrument itself.

What Are the Key Parameters?

The table below lists the main specifications of the EMT CGQ-1 non-intrusive pig signaller.

Parameter	Specification
Detection method	Ultrasonic / magnetic induction, non-intrusive
Mounting	Ratchet strap or steel band, no pipe cutting
Enclosure / wetted	Aluminium alloy housing; remote box in 316 on request
Ingress protection	IP66, explosion-proof enclosure
Working temperature	-39.8 °C to 80 °C
Output signal	4-20 mA, auto-reset, bidirectional detection
Display	LCD showing passage time
Pipeline size	From 2 in non-intrusive interface and up
Standards	Designed to ASME B16.5 and NACE MR 0175

These parameters cover most onshore and offshore pigging duties. All units are function-tested before dispatch, and we can supply NACE MR 0175 wetted parts for sour-gas service on request.

How does it work

The CGQ-1 uses a transducer and magnetic sensor to sense the pig as it passes the mounting point. The signal travels through a reverse magneto-resistive circuit, amplification, and filtering before the CPU confirms a genuine passage and lights the indicator. The LCD logs the time, and the 4-20 mA line carries the event to the control room without extra panels.

Use it at pig launcher and receiver stations, scraper traps, and any tie-in where passage confirmation matters. It suits oil, gas, and multiphase lines, including desert and offshore sites thanks to the wide temperature range and IP66 housing. EPC contractors also place signallers at intermediate checkpoints to locate a stalled pig quickly during a long-haul run. The wide operating range also makes the unit suitable for arctic and tropical climates without modification. Remote sites benefit most, because a single 4-20 mA loop removes the need for an operator to walk the line after every launch.

Why Choose Non-intrusive Pig Signaller?

• Non-intrusive clamp fits the pipe without hot work or shutdown, cutting installation time on live lines.
• Explosion-proof, IP66 housing survives rain, dust, and harsh field conditions year after year.
• Bidirectional detection covers pigs moving either way through the same installation point.
• Auto-reset frees operators from manual clearing after each run, ideal for frequent pigging.
• 4-20 mA output feeds existing SCADA without extra panels or field wiring changes.
• EMT manufactures in Shenyang and controls welding, machining, and testing in-house, so specification and delivery stay predictable.

Who Is EMT and Why Trust Us?

EMT  is a manufacturer of pigging and pipeline equipment with ASME U-Stamp capability and NACE-compliant fabrication. We supply pig signallers, launchers, receivers, and quick-opening closures to EPC contractors and pipeline operators worldwide. Our team supports selection, documentation, and after-sales so your pigging project stays on track from bid to commissioning.

With years of export experience across the Middle East, Asia, and beyond, EMT understands the paperwork, inspection, and lead-time demands of international pipeline projects. We also offer spare transducers and clamp kits to keep installed signallers running through multi-year campaigns. Meet us at OGA 2026 in Kuala Lumpur, Booth 7501, to discuss your pig signaller requirement face to face.

FAQ

Q: Can the CGQ-1 be installed without stopping the line?
A: Yes. The non-intrusive clamp mounts with a strap or band, so no cutting or hot work is needed and the line stays in service.

Q: Does it work for pigs moving in both directions?
A: Yes. The unit supports bidirectional detection and records each passage with a time stamp, so a single device covers both forward and reverse runs.

Q: What output does it provide to the control room?
A: A 4-20 mA signal carries the passage event to SCADA, while the on-site LCD shows the date and time of each detection.