Non-intrusive Pig Detector

Dh-fct magnetic explosion-proof passing indicator is a ground judgment instrument used to determine whether the pig passes or not during pigging of oil, gas, water, and other transmission pipelines. It is flexible and convenient to install and disassemble and can meet the requirements of various pipelines for indicators. It only needs to wrap and fix the indicators on the outer wall of the pipeline to work.



Instructions for use of Non-intrusive Pig Detector

Dh-fct magnetic explosion-proof passing indicator is a ground judgment instrument used to determine whether the pig passes or not during pigging of oil, gas, water, and other transmission pipelines. It is flexible and convenient to install and disassemble and can meet the requirements of various pipelines for indicators. It only needs to wrap and fix the indicators on the outer wall of the pipeline to work. Furthermore, it solves the problems that mechanical indicators are easy to ignite, mechanical faults are easy to occur, explosion-proof, affect the accuracy of ball passing judgment, and electronic indicators are prone to a false alarm and missing alarm due to interference. If you want to know more about Non-intrusive Pig Detector, please contact our professionals to answer them for you.

1. Product Composition

The magnetic explosion-proof passage indicator is composed of explosion-proof remote transmission display mechanism TZS (LCD has heating function, recording passage time, storing memory for 100 times, remote transmission, explosion-proof mark Exd iict6, protection grade IP65), sensing mechanism yy-fct, detachable card mounting mechanism, connecting wire and extension rod (for generally buried pipelines if necessary). The sensing mechanism of the magnetic explosion-proof pass indicator is composed of a reverse magnetoresistance circuit, a balanced amplification circuit, a low-pass filter circuit, a trigger circuit, a CPU, a supporting remote switch circuit, and a display circuit, and a reset circuit.

2. Use Characteristics

During the operation of the product, when the pig with magnetic force passes through, the passing time of the pig is displayed and a switch signal is transmitted remotely for the pigging process control to understand the operation of the pig. The display mechanism also stores and remembers the passing times and times. The memory times: 99 times.

3. Scope of application

1. Applicable temperature: – 40 ~ 85 “C.
2. Suitable for transmission pipes of all materials

The non-plug-in pigging indicator is a computerized electronic device. It has a magnetic sensor at the bottom. Therefore, this product does not need to be perforated on the pipe. We only need to fix it outside the pipe. It is on the outer upper part of the pipeline through which the pig needs to be detected. So when a pig with a magnet or a magnetic launcher arrives and passes. The magnetic sensor sends a signal to the computer on top of it. In this way, the product will display the arrival time of the pig on the LCD screen. Moreover, it can affect the instruments in the station instrument room through cables. Therefore, the instrument can display information and alarm. At the same time, it will continue to report the relay closing signal when the pig arrives.
Once it can detect the arrival of the pig. Its passing time and date will be recorded on display. Or in the computer memory of the non-plug-in pig indicator. And the results will also be displayed on the upper LCD screen. Except that the time of the last pig’s passing is recorded. The non-plug-in pig indicator also records the time of the previous 99 times of pig passing. Therefore, the operator opens the non-plug-in pig indicator user interface. In this way, we can quickly find the information of nearly 100 pig passes.

The weight of the Non-intrusive Pig Detector is about 4.2 kg. The overall dimension is about 480 mm long. About 200 mm in front and back. Its overall height is about 500 mm. We can manufacture it according to the user’s requirements.

Detection method

The non-plug-in pig indicator is designed to detect the passage of pigs by two different methods* They are magnets and magnetic pulse emitters. Each method has its own advantages. We will discuss it in detail below.


The Non-intrusive Pig Detector can detect the magnet fixed on the tail axis of the pig. (it is much smaller than the products of other companies). Magnets for this purpose can also be purchased from us. Magnets come in different sizes. This corresponds to pigs of different sizes. The magnets for 3 “~ 8” pigs have M10 bolts for installation at the tail of the pig. Other sizes of pigs have M12 bolts for installation at the tail of the pig. If a foam pig is used, a hole of appropriate size can be excavated in the center of the tail of the foam pig. Then we put the magnet in and fix it with glue. This can also make the foam pig have such functions.

The magnet of the pig is small and strong in function. Our products can detect high-speed moving pigs in gas pipelines. And the price is relatively cheap. And it requires no battery. The battery needs charging and maintenance. However, the use of magnets to detect pig passage has at least one disadvantage. That is if the pig is stuck in the pipeline. Because it is a static magnetic field, it is not easy to find.

If you think the pig may be stuck in the pipeline. We recommend that you use a dynamic emitter. (discussed below). It can not only make your non-plug-in pig indicator work smoothly. And when the pig is stuck in the pipeline, we can quickly find the position of the pig. If it is necessary to use the pig with the launcher, it is recommended to use the pig positioning and tracking system produced by our company. They have low-frequency pulsed magnetic field transmitters.


Non-intrusive Pig Detector may also detect emitters with strong pulsed magnetic fields. This dynamic transmitter has one advantage. It is easy to find the pig parked in the pipeline with our receiver. The user only needs to start from the detected position where the pig passes. We can use the detector to detect the pig stopped in the pipeline along the downstream direction.
However, the cost of dynamic transmitters is high. And he needs to maintain the battery to ensure the normal operation of the system. In particular, on pipelines for transporting gas. But if the moving speed of the emitter emitting the pulsed magnetic field is too fast. Then the inspection may be missed.

4. Security

Non-Intrusive Pig Signaller

This local non-plug-in pigging indicator has one advantage. That is, it is intrinsically a safe explosion-proof product. Therefore, when the local non-plug-in pigging indicator is powered by 3V battery, its current is 1.15ma. When the alarm instrument in the instrument room works for the power supply, the voltage is about 15v-24v. The current consumption is 5mA. When a short circuit occurs unexpectedly, the current is 12mA. Its power is far less than the national standard of less than 1.3W, which is the essential explosion-proof safety requirement.

Power supply, low power consumption

There are two modes of power supply for the local non-plug-in pigging indicator: first, local battery power supply. When the local battery works for power supply, most of the time its computer is in sleep. Its consumption current is less than 0.95ma. When the pig arrives, the computer is awakened to work. Its current is less than 1.15ma. Therefore, as long as two 1.5V alkaline batteries with a capacity of 10Ah are installed. The battery can be used for more than 1 year. Then, the local power is supplied by the alarm instrument in the control room. Power consumption < 5mA. If the battery is also used to supply power to the local non-plug-in pigging indicator. The battery consumes little power. Then we can use it for several years. Until the battery fails.

Indicator code





Intrusive China Passage Pig Signaller

 Indicator feature

Manual reset flag

Manual reset flag combined with electrical signals

Date and time display combined with electrical signals

Installing type

2″Welded base, nipple joint. Design pressure up to 3000Psi

Trigger type


Insert depth (In pipe)

13 mm

Plug body length


Insert depth adjustment

20 mm

Operating temperature

—20~120℃/Meet customer requirements

NACE MR – 01- 75


Ingress protection


Explosion-proof class

ExdⅡ BT4

ExdⅡ BT4

Include isolation valve


With bypass valve


With bleed valve


Remove under pressure



Special retriever

Our Non-intrusive Pig Detector uses a unique magnetic system to prevent fluid exchange blocked, therefore, it eliminates the risk of leakage from the action seal, also the trigger of the instrument is enhanced flexibility, reduces maintenance costs and is easy to install to pipelines.

Access Fitting Body

Why Choose Us?

1. Many kinds of pig signaller with a different type meet different requirements.
2. Samples will be offered to attest to the quality and our services.
3. The fastest feedback!
4. The fastest delivery time.
5.24 hours,7 days online.


1. Lightweight, clear lines, insulation, high strength, not easy to deformation.

2. Convenient construction, not suitable for bending and warping, and good tensile resistance of horizontal grain.

Shenyang EMT Pigging Technology Co., Ltd. was founded in 2004 and has now become a scientific research enterprise in the collection of research, product development, sales, and service. Products include instruments, meters, and other equipment under our research that have been widely used in ranges of petroleum, chemistry, mechanism, etc.  The following products get advanced feedback given about sustainable functions and dependable quality from customers in the project CONNC and CPECC( branch company of Sultan and Chad) including pig signaller, cleaning pig, corrosion coupon,and chemical injection quill


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