Services
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Magnetic Particle Inspection
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Dye Penetrant Inspection
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Ultrasonic Inspection
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Radiography Inspection
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Phased Array Ultrasonic Inspection
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Time Of Flight Diffraction (ToFD)
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Level III Consultancy
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Auditing
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Validation
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Bespoke Inspection Solutions
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Inspection equipment design and manufacture
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Procedures
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Weld Inspection
Phased Array Ultrasonic Testing (PAUT)
At Caledonia Inspection Services Ltd we endeavour to specialise and promote Phased Array Ultrasonic Testing (PAUT)
We enjoy the challenge and work closely with our client base to offer bespoke inspection solutions from procedure generation and equipment scanner manufacturing through to validation and in field inspection.
PAUT Corrosion Mapping
Caledonia Inspection Services Ltd supply the Olympus NDT HydroFORM and RexoFORM to offer the best inspection solution for the detection of wall-thickness reductions due to corrosion, abrasion, and erosion in pipework, tanks, and vessels. This semi-automated inspection system solution also detects mid-wall damage such as hydrogen-induced blistering or manufacturing-induced laminations, and easily differentiate these anomalies from loss of wall thickness.
With the addition of supplementary advanced ultrasonic techniques ToFD and TFM we can offer confidence and reliability in predictive maintenance increasing your asset reliability.
PAUT Bolt and Fastener Inspection
Fasteners including bolts,nuts and studs are susceptible to failure from defects such as corrosion,and fatigue cracking.
Often difficult to remove due to time and plant constraints for surface inspections such as MT,PT and VT. PAUT offers a validated, fast, and cost effective means of inspection.
At Caledonia Inspection Services Ltd we offer a proven and unique solution.
Phased Array Ultrasonic (PA)
Phased array ultrasonic (PA) is an advanced method of ultrasonic testing that has applications in industrial nondestructive testing.
The PA probe consists of many small ultrasonic transducers, each of which can be pulsed independently. By varying the timing, for instance by pulsing the elements one by one in sequence along a row, a pattern of constructive interference is set up that results in a beam at a set angle. In other words, the beam can be steered electronically. The beam is swept like a search-light through the object being examined, and the data from multiple beams are put together to make a visual image showing a slice through the object.
Phased array is widely used in several industrial sectors, such as construction or power generation. This method is an advanced NDT method that is used to detect component failures i.e. cracks or flaws and thereby determine component quality. Due to the possibility to control parameters such as beam angle and focal distance, this method is very efficient regarding the defect detection and speed of testing. Apart from detecting flaws in components, phased array can also be used for wall thickness measurements in conjunction with corrosion testing. Phased array can be used for the following industrial purposes:
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Inspection of Welds
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Thickness measurements
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Corrosion inspection
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Flaw detection
Dye penetrant inspection (DPI)
Dye penetrant inspection (DPI), also called liquid penetrant inspection (LPI) or penetrant testing (PT), is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials and ferrous materials; although for ferrous components magnetic-particle inspection is often used instead for its subsurface detection capability. LPI is used to detect casting, forging and welding surface defects such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks on in-service components.
DPI is based upon capillary action, where low surface tension fluid penetrates into clean and dry surface-breaking discontinuities. Penetrant may be applied to the test component by dipping, spraying, or brushing. After adequate penetration time has been allowed, the excess penetrant is removed and a developer is applied. The developer helps to draw penetrant out of the flaw so that an invisible indication becomes visible to the inspector. Inspection is performed under ultraviolet or white light, depending on the type of dye used - fluorescent or nonfluorescent (visible).
Welding Inspection (WI)
Welding Inspection (WI) at Caledonia Inspection Services LTD we have technicians qualified as Welding Inspectors. Inspectors are qualified to CSWIP or PCN standards.
Welding inspectors can carry out duties ranging as follows:
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QA roles
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Preparation of hand over packages to clients
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Visual inspections
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Radiographic Interpretation
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Interpretation of drawings
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Supervising NDT procedures
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Document Control
Other duties can be carried out at client’s requests also.
Time-of-Flight Diffraction (TOFD)
Time-of-flight diffraction (TOFD) method of ultrasonic testing is a sensitive and accurate method for the nondestructive testing of welds for defects.
Measuring the amplitude of reflected signal is a relatively unreliable method of sizing defects because the amplitude strongly depends on the orientation of the crack. Instead of amplitude, TOFD uses the time of flight of an ultrasonic pulse to determine the position of a reflector.
In a TOFD system, a pair of ultrasonic probes sits on opposite sides of a weld. One of the probes, the transmitter, emits an ultrasonic pulse that is picked up by the probe on the other side, the receiver. In undamaged pipes, the signals picked up by the receiver probe are from two waves: one that travels along the surface and one that reflects off the far wall. When a crack is present, there is a diffraction of the ultrasonic wave from the tip(s) of the crack. Using the measured time of flight of the pulse, the depth of a crack tip can be calculated automatically by simple trigonometry. This method is even more reliable than traditional radiographic, pulse echo manual and automated weld testing methods.
Ultrasonic Testing (UT)
Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of the test object, for example, to monitor pipework corrosion.
In ultrasonic testing, an ultrasound transducer connected to a diagnostic machine is passed over the object being inspected. The transducer is typically separated from the test object by a couplant (such as oil) or by water, as in immersion testing.
There are two methods of receiving the ultrasound waveform: reflection and attenuation. In reflection (or pulse-echo) mode, the transducer performs both the sending and the receiving of the pulsed waves as the "sound" is reflected back to the device. Reflected ultrasound comes from an interface, such as the back wall of the object or from an imperfection within the object. The diagnostic machine displays these results in the form of a signal with an amplitude representing the intensity of the reflection and the distance, representing the arrival time of the reflection. In attenuation (or through-transmission) mode, a transmitter sends ultrasound through one surface, and a separate receiver detects the amount that has reached it on another surface after traveling through the medium. Imperfections or other conditions in the space between the transmitter and receiver reduce the amount of sound transmitted, thus revealing their presence. Using the couplant increases the efficiency of the process by reducing the losses in the ultrasonic wave energy due to separation between the surfaces.
Magnetic particle Inspection (MPI)
Magnetic particle Inspection (MPI) is a non-destructive testing (NDT) process for detecting surface and slightly subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys. The process puts a magnetic field into the part. The piece can be magnetized by direct or indirect magnetization. Direct magnetization occurs when the electric current is passed through the test object and a magnetic field is formed in the material. Indirect magnetization occurs when no electric current is passed through the test object, but a magnetic field is applied from an outside source. The magnetic lines of force are perpendicular to the direction of the electric current which may be either alternating current (AC) or some form of direct current (DC) (rectified AC).
The presence of a surface or subsurface discontinuity in the material allows the magnetic flux to leak, since air cannot support as much magnetic field per unit volume as metals. Ferrous iron particles are then applied to the part. The particles may be dry or in a wet suspension. If an area of flux leakage is present, the particles will be attracted to this area. The particles will build up at the area of leakage and form what is known as an indication. The indication can then be evaluated to determine what it is, what may have caused it, and what action should be taken, if any.
