URINDT - Review of NDT tools for inspection carrying out in the pipe industry.

Review of NDT tools for inspection carrying out in the pipe industry.

Yurchenko А.V. – engineer of “Ukrainian research institute for non-destructive testing” CJSC

In recent years there is a tendency of onrush development and increase of competitiveness of enterprises-representatives of Ukrainian pipe industry. It is quite easy to explain as manufacturers improve the quality and volume of produced products what gives them an opportunity to remain monopolists in Ukrainian market and work up new foreign markets of manufactured products outlet. As it has already been mentioned, undisputed contribution to the development of this branch was made by the customer’s guarantee of product quality offered to the customer. In its turn, it is attainable only if the items are qualitatively tested when being manufactured.

Along with the necessity of testing of finished pipe products at their production, there is a need of constant inspection of operated objects in gas and oil processing, petrochemical production sectors, heat and power engineering.

Treating this subject, one may say that today the tools of automated and manual non-destructive testing of products quality which are used in domestic plants require overall modernization and even complete replacement. Considering a sharp need of enterprises in modernization of existing and in purchasing of new automated testing systems, “OKO” association represented by “Uktracon-Service” production association, “Promprylad” LLC and Ukrainian research institute for non-destructive testing continue scientific production work in the present NDT field.

Speaking of our enterprises achievements in the sphere of automated pipe products testing, the following systems are worth mentioning:

The system of automated ultrasonic testing on the basis of “Uniscan-LuCH” - SAUZK “Uniscan-LuCH KТ-7” multi-channel ultrasonic flaw detectors intended for ultrasonic inspection of end-areas of pipes with diameter from 406 to 1422 mm, wall thickness from 6,3 to 40,7 mm and length of up to 12.5 m.

“Uniscan-LuCH KТ-7” system of automated ultrasonic testing of pipe end-areas enables to perform simultaneously complex 100% ultrasonic testing over the whole pipe wall thickness (except near and far “dead areas”) for the presence of longitudinal cracks and planar defects, such as delaminations.

Appearance of SAUZK “Uniscan-LuCH KТ-7”system mechanical part

Ultrasonic scanner in operation

The system provides ultrasonic areas testing at each end of 540 mm wide pipe. The system measures the signal amplitude, depth and angular coordinates of detected defects, pipe wall thickness and evaluates conditional length and area of detected defects.

Hardware and computing complex and system controls

Appearance of interface of testing programs and setup

“Uniscan-LuCH KТ-7” system of automated ultrasonic pipe end-areas testing provides 100% registration of testing results, in particular:

recording and storing of results and on-line display of testing process information in the form of defectogram – these data enable to evaluate the testing results directly in the course of inspection;
testing results printing and storing on electronic data carrier. Remote operation with the stored data archives, formation of different forms of the received results reports are provided by means of a special software kit;
on the customer’s will the testing results information may be transmitted to ACS shop OP (automatic control system of the shop operating procedure).

Main technical specifications of the system:

execution of ultrasonic testing of pipe end-areas with diameter from 406 to 1422 mm, with wall thickness from 6,3 to 40,7 mm.
detected defects types: planar defects, such as delaminations and longitudinal cracks;
number of ultrasonic channels – 48;
operating frequencies of ultrasonic probes – 2.5, 5 МHz;
refracted angles – 0°, 45°.
individual tracking of every probe acoustic coupling;
automatic pipe end tracking during testing;
separate marking of defect area coordinates and of pipe testing fact;
automatic flaw alarm system (ALARM);
video surveillance system integration option;
time of flaw-free testing without taking into account the time of load-unload on the testing site – no more than 2 minutes;
100% registration of testing results.

system of automated ultrasonic testing of longitudinal pipe welds with diameter from 406 to 1422 mm and wall thickness from 6,3 to 40,7 mm on the basis of “Uniscan-LuCH” - SАUZK “Uniscan-LuCH PSH-10” multi-channel ultrasonic flaw detector.

Three similar automated systems will be incorporated in manufacturing lines of KTRP in the first quarter of 2008.

The system carries out ultrasonic testing of longitudinal pipe welds with diameter from 406 to 1422 mm and wall thickness from 6,3 to 40,7 mm for the presence of internal defects, such as slag inclusions, pores, transverse and longitudinal cracks along the whole weld length, except dead areas of no more than 180 mm at the pipe ends. The system measures the depth and longitudinal coordinates of detected defects, evaluates conditional length of detected defects in the pipe weld by the level of 0,5 from max. amplitude of echo-signal.

SАUZK “Uniscan-LuCH PSH-10” system in operation

The system performs the following functions:

recording, storage of results and on-line display (in the form of defectogram) of testing process information (the testing report form is agreed with the Customer at the stage of design engineering);
testing results (testing report) printing and storing on electronic data carrier;
LED and sound alarm on the defect presence;
paint marking of pipe sections defining the defects location;
transmission of testing results information into the shop OP ACS (automatic control system of the shop operating procedure).

Main technical specifications of the system:

execution of ultrasonic testing of longitudinal pipe welds with diameter from 406 to 1422 mm and wall thickness from 6,3 to 40,7 mm.
detectable defects types: according to API SPEC 5L;
ultrasonic channels quantity – 8 (in one module);
ultrasonic probe operating frequencies – 2.5 МHz;
refracted angles – 50°, 65°.
individual tracking of every probe acoustic coupling;
marking of the longitudinal coordinate of defective section as well as of the pipe testing fact;
automatic flaw alarm system (ALARM);
flaw-free pipe inspection time without taking into account the time of loading-unloading on the testing site – no more than 2,5 minutes;
100% registration of testing results.

One of our enterprises achievements in the sphere of NDT equipment development is ОKО-01 multi-channel universal flaw detector which, according to its versatility and flexibility of application, is an essential tool for carrying out NDT mechanization at the enterprises. Flaw detector is performed in two variants: eddy current and ultrasonic.

Main technical specifications of ОKО-01 multi-channel ultrasonic flaw detector:

testing results viewing in real time by the selected channel in “А-scan”, “B-scan” display mode;
registration of places of acoustic coupling loss and scanning speed exceeding in “Defectogram” mode;
sound and LED alarm at all testing techniques actuation, acoustic coupling loss and scanning speed exceeding.
100% registration of testing results and conditions;
profound analysis and monitoring of technical state of testing items;
probe operating frequencies – 2.5, 5 МHz;
combination of small dimensions and weight and capacities of multi-channel systems;
issue of quality certificate for the testing object;
max. number of ultrasonic channels – 32;
color TFT display;
Flash card (for testing data storage);
USB slave;

Information display modes when testing welded joints in B-scan and defectogram modes by means of ОKО-01 ultrasonic instrument

Main technical specifications of ОKО-01 multi-channel eddy current flaw detector:

testing results viewing in real time by the selected channel in “hodograph” mode as well as in band diagrams mode;
sound and LED alarm at all testing techniques actuation;
100% registration of testing results and conditions;
in-depth analysis and monitoring of technical state of testing items;
wide range of operating frequencies (from 100 Hz to 2 МHz)
combination of small dimensions and weight and capacities of multi-channel systems;
issue of quality certificate for the testing object;
max. number of ultrasonic channels – 128;
color TFT display;
Flash card (for testing data storage);
USB slave;

Information display modes when testing welded joints by means of ОKО-01 eddy current instrument

The series of scanning devices has been developed at our enterprises and operated in NDT services of GazProm (Russia). The scanners are intended for carrying out ultrasonic flaw detection of welded joints of industrial and main pipelines. The present series of scanning devices is designed for operation together with ОKО-01 universal multi-channel flaw detector and applied for testing the ring welded joint quality.

SKТ-TS scanner during large-diameter pipes testing

SKТ-TS scanners are used for performing ultrasonic testing of pipes with outer diameter from 219 to 1420 mm and provide complete ensounding of the ring welded joint with thickness from 4 to 60 mm.

Ultrasonic probes units of SKТ-TS scanner on the adjustable bar

The usage of replaceable ultrasonic probes units - АB1, АB2, АB3, АB4 - in the scanner allows to provide ultrasonic testing in the whole range of stated thicknesses.

Acoustic units purpose:

АB1 – testing of welded joints of pipes with wall thickness from 4 to 15 mm
АB2 – testing of welded joints of pipes with wall thickness from 15 to 25 mm
АB3 – testing of welded joints of pipes with wall thickness from 20 to 40 mm
АB4 – testing of welded joints of pipes with wall thickness from 35 to 40 mm

Below there is the series of scanners (SKТ-М) intended for small- and medium-diameter pipes testing:

SKТ-М-1 – testing of welded joints of pipes with outer diameter from 89 to 114 mm and wall thickness from 4 mm to 15 mm;
SKТ-М-2 – testing of welded joints of pipes with outer diameter from 114 to 168 mm and wall thickness from 4 mm to 15 mm;
SKТ-М-3 – testing of welded joints of pipes with outer diameter from 168 to 219 mm and wall thickness from 4 mm to 15 mm;

pipe pressing levers
pair of acoustic units

Then, there are also the testing schemes performed in the above-listed ultrasonic scanners variants.

echo-mirror technique together with echo technique serve for defects detection and their type determination, evaluation of defect length development along the weld section and base metal;

echo images technique of testing is intended for estimating the level of ultrasonic waves attenuation in the welded joint and base metal, and also the changing of acoustic coupling quality.

Ultrasonic testing of welded joints of tanks, vessels and other sheet products is carried out using special-purpose scanner on the basis of ОKО-01 ultrasonic flaw detector.

The following sounding schemes are used in the present system configuration:

echo technique by the straight beam in different directions;
echo technique by the reflected beam in different directions;
several variants of “tandem” scheme;
several variants of “duet” scheme;
all possible variants of echo images technique of testing.

Scanner for the testing of longitudinal joints of sheet products

To perform mechanized testing of pipelines, several scanning devices have been developed for ОKО-01 eddy current flaw detector.

Experimental-industrial check of “ОKО-01” universal multi-channel eddy current flaw detector together with eddy current scanners applied for pipelines testing was successfully performed on the section of gas-main pipeline “Perm-Kazan-Gorkiy 2” *(341-354km) of Mozhginsk gas-engineering center “Gaznadzor” LLC and “Spektr KSK” CJSC.

“CRAB” semi-automated system has been also developed at our enterprises. It provides 4-channel two-frequency automated testing of pipes during their operation and consists of the scanning device, industrial computer, 4 identical eddy current boards and scanner control board. Eddy current boards provide the generation of signal of eddy current probe excitation and the processing of signal received from eddy current probe.

Technical specifications:

Diameter of testing pipes – 102 mm, wall thickness – up to 10 mm;
Evaluation and storage of detected defects coordinates;
Range of operating frequencies – up 1,5 to 5 kHz;
ALARM system;
Number of eddy current probes – 4 pcs.;
Speed of scanning along the pipe axis – 1m/min;
Data transmission to archives and testing report creation.

Having placed the scanning device on the pipe, without data acquisition it moves downwards until the probe of lower position is actuated (when touching with collector, the probe generates the signal of lower position). At the actuation of probe of lower position the data acquisition is begun. Whereby, after every step of scanning device upwards, the unit of eddy current probes makes a turn. When the scanner reaches the reformer crown, the probe of upper position is activated and the scanner, having stopped data acquisition and without rotation of the unit of eddy current probes, moves downwards to the operator set number of steps. After the scanner has stopped, it is removed and placed on the next pipe. 100% eddy current testing of stainless pipes with wall thickness of 15 mm made of stainless steel is performed by means of CRAB system. Upon that, internal defects, such as a crack with depth of more than 50 % from the pipe wall thickness and external defects with depth of more than 20 % from the wall thickness are detected. The system tests 10 m of pipe per 10 minutes, stores all collected data of eddy current flaw detection, outputs on-line testing results.

Thus, having reviewed all systems and manual NDT tools for pipe industry manufactured by our enterprises, it is possible to show the customer a constant tendency for enterprises development of “ОKО” association in the sphere of new technologies and NDT tools designing.