A "PIG" ( pipe inspection gauge ) is a device which is inserted into and run through a pipeline to perform a specific function. Pigs can be separated into two classes; non intelligent pigs and intelligent pigs. Non intelligent pigs perform a basic operational function such as swabbing, batching , cleaning. Intelligent pigs collect data as to the integrity or performance of the pipeline such as diameter measurement/geometery, corrosion detection, crack detection and leak detection.

When a pig becomes stuck or lodged in the pipeline due to an obstruction, the pipeline must be taken out of service, and the point of obstruction located and cleared. This down time could result in hundreds of thousands of dollars in lost revenue for every day the line is out of service.

To assist in locating the location of a stuck pig, a battery powered pulsating electronic transmitter is attached to a pig prior to the insertion into the pipeline. As the pig travels down the pipeline a technician uses a tuned electronic receiver to pick up the pulsed signal from the transmitter as the pig passes beneath preselected monitoring points. These monitoring points are situated at road crossings or other areas that are accessible.

Corrpro Companies use various manufacture brands of pig tracking receivers. Most of the receivers used at Corrpro is the Herman Sewerin, followed by the Pipetronix brand and the Heggerud brand. All of the receivers comprise of a power supply, search coil, amplifier and either a headset or speaker. The voltages that are induced inside the search coil by the pig transmitter are displayed both visually and acoustically by means of the amplifier.

Herman Sewerin

The receiver is equipped with eight ( 1.5 volt C cell ) batteries connected in series to yield 12 volt of power. These batteries need to be replaced when the current level of the batteries are below the voltage level. Battery checks can be made by depressing the "battery check" button on the older model units or the by the instrument with color-classification on the newer models. The search coil is required to be connected to the receiver in order to check the state of the batteries.

Pipetronix (Kopp)

This receiver is equipped with eight (1.5 volt C cell ) batteries connected in series to yield 12 volts of power. These batteries need to be replaced when the instrument indicates low battery level.

Heggerud (Quintessa)

The Receiver is a state of the art Micro-controller based design ( a micro-controller is a microprocessor with on board memory). Filtering is accomplished in two ways. There is a state of the art analog filter at the input stage. Unique to this design also is a gain controlled input stage gain . This allows the input filter to operate at its optimum level for the field operating conditions. Despite the state of the art analog filter at the input stage, only about 5 percent of the receivers filtering is achieved here.

The remaining 95 percent of the filtering is accomplished by the micro-controller through the use of digital signal processing (dsp) algorithms. The result is a receiver with vastly improved noise rejection. This filtering system makes walking to find a stuck pig much quicker as the normal step, stop, listen routine is not necessary. You simply walk.

The receiver is compact ( 2 3/8" h x 6 ¼" w x 7 ½" l ) and has a vacuum fluorescent display that withstands temperatures from –55 deg. To 85 deg. C. The receiver is powered by rechargeable sealed lead acid batteries. These batteries have several advantages including long operating times. The batteries can be left on a float (trickle) charge so that the receiver is always ready to operate. There is a built in charger system that allows the batteries to be charged from virtually any source, including A.C. converters or from cigar lighters.The display is also unique; it displays all the important operating parameters at a glance.

The receiver can be used easily by untrained personnel but yet allows for unequalled flexibility in difficult ambient operating conditions such as high electrical noise. It is also possible to locate pipe with this UNIT.

The Model III transmitter is 1 ½" dia. X 6 ¼" long. It has a range of about 60 ft in air and a battery life of approximately 200 hours on two standard 9 volt batteries. A modified version of the Model III allows the transmitter to run on six 1.5 volt "C" batteries with a range of 80 ft in air and a battery life of approximately 500 hours.

The Model 1V transmitter 2" dia. X 6" long, has a range of about 80 ft in air. The power pack, which holds 8 "C" cell batteries provides over 600 hours of operating time.