TCR Arabia conducts ultrasonic thickness measurement of plates, pipes and machined components, refinery, Petrochemical plant piping /pipelines, Storage tanks and Bullets using pulse echo flaw detectors having integral gating to produce digital reading or using ultrasonic thickness meters. TCR site in charge shall be responsible for the control, coordination and Documentation of all items tested for UTM as per the schedule received from client. TCR site in charge will ensure effective communication is maintained with the client with respect to the assigned UTM Testing project.
The NDT Controller delegated for the control and coordination of NDT activities shall issue the UTM Inspector with a daily written list of materials ready for inspection.
The UTM Inspector shall be responsible for conducting and reporting the results of inspection is accordance with this Procedure.
Codes and Standards
ASME Boiler and Pressure Vessel Code, Section V, Nondestructive Examination
ASNT Recommended Practice No. SNT-TC-1A, Personnel Qualification and Certification in Nondestructive Testing.
ANSI / ASNT CP 189, Standard for Qualification and Certification of Nondestructive Testing Personnel
ASME B31.1, Power Piping
ASME B31.3, Process Piping
API 620, Design and Construction of Large Welded Low Pressure Storage Tanks
API 650, Welded Steel Tanks for Oil Storage
API 1104, Welding of Pipelines and Related Facilities
Areas, which shall be ultrasonically measured for thickness, shall be prepared to the extent necessary to provide a sufficiently smooth and regular area for the reading to be taken. Such area shall normally be scraped; wire brushed or ground* to bare metal and shall be free of any irregularities that may hinder the accuracy of the reading.
Equipment at TCR Arabia
Pulse-echo type Equipment
Thickness measurement shall be carried out using pulse - echo type equipment capable of generating and receiving frequencies of 5MHz and having integral gating to produce digital reading.
Krautkrammer make USN58, Panametrics - EPOCH LT or similar equipments will be used.
Ultrasonic thickness meter
Thickness meters working on the principle of measuring the time of flight of an ultrasonic pulse through the test specimen and multiplying this time by the velocity of sound in the material shall be used. Krautkramer make model DMS, DM series, DL series, Panametrics make Model 26MG or similar may be used.
Calibration of thickness meters shall be undertaken by setting the material sound velocity and adjustment with two known thickness on a calibration block, one on higher side and another on lower side to the expected thickness to be measured.
Transducer and flaw detectors shall be electrically matched to the unit. Care shall be taken in using transducers specifically supplied for “thickness meters” shall not be used with “pulse echo” type equipments.
Each unit shall have transducer(s) of type, size and frequency compatible with the unit and in line with the governing specification. Transducer shall generally be twin crystal, longitudinal wave type not exceeding 25mm diameter for thickness of less than 350mm. Single crystal transducers can be used with compatible Thickness Meter. Transducer with badly worn or damaged faces shall not be used.
Calibration blocks, in the form of specific thickness of material, or as step wedge, shall accompany the instrument. Machined parallel faces of the test specimen may also be used for calibration purpose, where none available.
Documentation And Reporting Of Test Results
Subject to Client’s governing specification, the readings shall be recorded in millimeters on the relevant area of sketch or supplied drawing alternatively results shall be presented in tabular form.
Each examination or survey shall be reported in the test report form or related to drawing/sketch and the report shall give the following information as a minimum:
- Client Name, PO / request no.
- TCR job no.
- Drawing/line number
- Item or weld number
- Type of equipment, Probe and Cal. Block used.
- Consumable materials used
- Technician’s name.