Ultrasonic pig detector device ULIS-A
ULIS-A is ultrasonic pig passage detector designed to detect pig devices passing in pressure (fully filled) pipeline under the flow of liquids, registration of moment of pig device crossing the controlled section of the pipeline and signal issue upon detection into the data acquisition system or to ACS.
The indicator consists of an electronics unit (EU) and electroacoustic transducer (EAT) to be mounted on the surface of the pipeline with a mounting hardware. EAT is connected to EU by a four-wire cable. The appearance of ULIS-A is shown in the figure below.
- fixing the moment of pig device detection (event);
- storage of events in non-volatile memory;
- display on the indicating device of registered events and emergencies;
- display of diagnostic, reference and archival information to the external devices via serial RS-485 interface.
ULIS-A is designed for continuous operation and requires minimal maintenance. The EU outputs are connected to the telemetry system. EAT provide emission and reception of ultrasonic signal forming the acoustic channel crossing the liquid flow in diameter. According to the principle of operation, the pig detection device is an active radar constantly scanning controlled section of a pipe. The pig detector analyzes level of ultrasound signal and noise, and compares them with the values obtained during the adaptation process of the device. The decision of the pig device passage is carried out upon the analyses of signal levels and time rate.
The pig detectors provide signal issue for data gathering systems/telemetry at the moment of detecting a pig device at the time of mud-paraffin plug passage. Signal type – “dry contact”, at the time of detection provides closure of the respective pair of contacts. The device performance monitoring is carried out by supplying 24V voltage to the device “control” input.
On request, ULIS can be manufactured with the required type of output signal. Compared to other devices of analogous application, the indicators are free from false operations when mains supply cut-in or cut-off and when influenced by electromagnetic interference of lighting discharge or electric welding.
ULIS-A is intended to:
- register the pig passage, as well as batching spheres, calibers, diagnostic devices, etc.;
- determine the size of the mud-paraffin plugs enabling to alert emergency situations caused by filters clogging on the oil metering units by timely discharge of polluted flow;
- determine the density of mud-paraffin plug enabling to control the degree of pipeline purification;
- register plugging (clay plug) during the repair works and prevent failure of metering units, or damage caused by clogged inlet filters;
- to register occurrence of gas inclusions in the pipeline, which can result from pumps cavitations, non-optimal operation modes of the pipeline, etc.;
- to change the density to determine the boundary between the different batches of oil, including the parties to the high sulfur content, which is especially important when transporting oil for export.
|Parameters of the indicator||Value|
|Diameter of the pipeline, mm||350 – 1200|
|Speed of movement of the pigging device in the pipeline, km/h||1-8|
|Length of the device of clearing, m||1-2|
|Environment temperature||-40…+60 °С|
|Voltage device||220 V, 50 Hz|
|Power consumption, Wt, no more||6|
|1. “Dry contact” “Event”||30 V, 200 mА|
|2. “Dry contact” “Fuse”||30 V, 200 mА|
|3. Current output||4 – 20 mА|
|4. Serial interface||RS-232/RS-485|
|Distance from the gauge up to the electronic block, m, no more||150|
The indicator is equipped with standard current output to display on an external device level of the ultrasonic signal. Range of current signal ranges from 4 to 20 mA.
To communicate with the PC, the indicator is equipped with interface module RS 485. Baud rate 9600 bit/s, the protocol MODBUS – alike. The PC can be removed from the EU on the distance up to 1200 m (on the downlink) via a two-wire line “twisted pair” with a characteristic impedance of 120 ohms. A time corresponding to the passage of the pig or emergency situations in the indicator are recorded in the archives. The volume of the archives – 128 entries. When the archive is full, the oldest entries are replaced. The archives are stored in the absence of mains power. Pig detectors of ULIS type have been produced since 1997. To date, there have been manufactured more than 1,500 devices of various modifications that are installed on more than 7,000 km of oil trunk pipelines in Russia, Ukraine, Belarus, the Baltic countries, Poland, Kazakhstan and India.
The largest companies are customers of ULIS: “Transneft” (Russia), OAO “Ukrtransnafta” (Ukraine), Gomeltransneft “Druzhba” (Belarus), Novopolotsk oil transportation enterprise “Druzhba” (Belarus), LatRosTrans (Latvia), KazTransOil (Kazakhstan), Oil India Ltd. (India).