Also known as Liquid penetrant inspection,Dye penetrant testing is the most reliable method of finding defects and discontinuities opened on the surface especially in all non-porous materials. This method is widely used for testing of non-magnetic materials.
In PT method, a liquid/dye penetrant is applied to the surface of the product for a certain predetermined time specified by codes, standards or specifications, after which the excess penetrant is removed from the surface. The surface is then dried and a developer is applied to it. The penetrant which remains in the discontinuity is absorbed by the developer to indicate the presence as well as the location, size and nature of the discontinuity. Penetrants used are either visible dye penetrant or fluorescent dye penetrant. The inspection for the presence of visible dye indications is made under white light while inspection of presence of indications by fluorescent dye penetrant is made under high intensity ultraviolet (or black) light under darkened conditions.
The Liquid penetrant testing facility is provided:
Radiographic Testing method is useful for the detection of internal flaws in many different materials and configurations especially used for quality assurance of castings, forgings and welds. An appropriate radiographic film is placed behind the test specimen and is exposed by passing either X-rays or gamma rays through it. The intensity of the X-rays or gamma rays while passing through the product is modified according to the internal structure of the specimen and thus the exposed film, after processing, reveals the shadow picture, known as a radiograph, of the product. It is then interpreted to obtain data about the discontinuities present in the specimen.
Quality NDT Services is equipped with latest equipments, radioactive isotopes (Ir-192), X-ray machines for a radiographic inspection and high intensity illuminators suitable for high density file interpretation. The radiography technicians are experienced in inspection of castings in foundries, weldments in heavy fabrication, cross country pipelines, petroleum refinery piping, nuclear and aerospace components. Consultancy services can also be provided by our in house ASNT NDT Level IIIs in the method.
Our Radiography testing professionals are qualified, certified to Level I, II in the Radiography Testing and Radiographic interpretation as per ASNT recommended practice number SNT-TC-1A.
Ultrasonic Testing is an NDT method applied to detect internal flaws in materials, components and structures. Ultrasonic is sound beyond the human audible range that is 20Hz to 20kHz. Ultrasonic inspections use frequencies of above 0.5MHz up to 25MHz to test metals, ceramics, glass, composite and other engineering materials.
The ultrasonic waves travel through the material with some loss of energy (attenuation) due to material characteristics. The intensity of ultrasonic waves is measured, after reflection at interfaces (or flaw) or is measured at the opposite surface of the specimen (through transmission). The reflected beam is detected and analyzed to define the presence and location of flaws. The degree of reflection depends largely on the physical state of matter on the opposite side of the interface, and to a lesser extent on specific physical properties of that matter. For instance, ultrasonic waves are almost completely reflected at metal-gas interfaces, partial reflection occurs at metal-liquid or metal-solid interfaces. Ultrasonic testing has a superior penetrating power than radiography testing and can detect flaws deep (up to 5metre of steel) in the test objects. UT is quite sensitive to small flaws and allows the precise determination of the location and size of the discontinuities.
Ultrasonic testing is commonly used for inspecting castings, rolled bars, plates, forgings, thin sheets, extruded components, drawn components, welds and to measure reduction in thickness of pipes, vessels and other components.
To improve manufacturing quality and product reliability, components and structures are regularly inspected for discontinuities, defects or faults which may reduce their structural integrity leading to failure. Among the material testing methods developed for inspection purposes, Non-destructive testing (NDT) techniques present the advantages of leaving the components undamaged after inspection.
Quality NDT Services inspection facilities are equipped with modern NDT equipments, approved practices, procedures, qualified and certified NDT Level I, II, technicians and in-house ASNT NDT III certified professionals, materials testing experts, welding inspection and quality control personnel.
Visual Inspection is one of the most common and most powerful means of non-destructive testing. Visual testing requires adequate illumination of the test surface and proper eye-sight of the tester. To be most effective visual inspection does however, merit special attention because it requires training (knowledge of product and process, anticipated service conditions, acceptance criteria, record keeping, for example) and it has its own range of equipment and instrumentation. It is also a fact that all defects found by other NDT methods ultimately must be substantiated by visual inspection. VT can be classified as Direct visual testing, Remote visual testing and Translucent visual testing. The most common NDT methods MT and PT are indeed simply scientific ways of enhancing the indication to make it more visible. Often the equipment needed is simple for internal inspection, light lens systems such as bore scopes allow remote surfaces to be examined. More sophisticated devices of this nature using fibre optics permit the introduction of the device into very small access holes and channels. Most of these systems provide for the attachment of a camera to permit permanent recording.
Quality NDT Services material testing facility contains light meters, welding gauges, magnifiers, lenses, other measuring instruments and equipments for precise control of surface quality. Our NDT inspectors, engineers and technicians are qualified to NDT Level I, II as per written practice prepared according to ASNT recommended practice SNT-TC-1A and in-house ASNT NDT Level IIIs for providing inspection and consulting services.
Magnetic particle testing is a method for detecting cracks and other discontinuities on surface and subsurface of ferro-magnetic materials. Sensitivity of detection is maximum at the surface and diminishes rapidly with increasing depth of sub-surface defects. Detection of defects depend on the fact that when a material is magnetized, discontinuities which lie transverse to the direction of magnetization cause distortion of the magnetic lines of flux and a leakage field is formed at or above the surface, some of these particles are held by the leakage flux. These magnetically held collection of particles form outline of effects and show location, shape and extent of the discontinuities. A number of factors such as direction and strength of the magnetic field, magnetic character of the part, location and orientation of discontinuities and type of the magnetic powder applied, affect the formation of the powder pattern, and therefore exact location of the flaw is indicated by the method.
The Magnetic particle inspection facility is equipped with:
Quality NDT Services added the welding inspection and related services for the clients in and around Pune, India. Quality NDT Services is equipped with facilities for carrying out welder qualification tests and related activities.
In any manufacturing process where welding is involved, the quality of welding is most important feacher. The weld joint must be capable to withstand specified pressure or any type of stresses being developed during process of applying pull,bending or compressive type of processess. Also the weld joint should be capable to withstand stresses resulting from fluctuations taking place in environment temperatures. Weld joints are inspected by method of Radiographic Testing ( RT), Ultrasonic Testing (UT), Magnetic Particle Testing (MPT) and Liquid Penetration Testing (LPT).
Computed Radiography (CR) uses phosphor-imaging plates instead of film to store radiographic inspection results. CR imaging plates are exposed as per standard radiographic testing, but the images are laser scanned from the plates into a computer system. Using powerful software one can then analyze, print and store the images for future review.
Computed Radiography has various advantages over conventional radiography.
1) Developing time of film is eliminated in this technique. After exposure, scanning of an imaging plate takes less than one minute. This makes radiography testing much faster.
2) Permanent record will be stored in digital format.
3) The images can be readily shared, e-mailed and stored electronically by anyone needing reliability information for the equipment.
4) Defect size can be measured accurately using different tools provided by software, which increases confidence of inspector.
5) The imaging plates practically eliminate re-shots by providing a greater range over which exposures can be useful.
6) Significant exposure reductions
7) Reduction of exposure times from 50-70% when using IR 192
8) Similar or better results are obtained when utilizing Se 75, Co60 and X-rays
9) Highly reproducible
10) Data is stored for future comparison or audit
Computed radiography can be used for testing of weldings and casting.
Quality NDT Services has provided Computed Radiography Services to HPCL Mumbai Refinery for thickness measurement and pitting analysis of insulated pipes. For this application special software named Rhythm is used.
There are a number of methods used for the inspection of corrosion under insulation. The main methods are -
1) Insulation removal
2) Ultrasonic spot readings
3) Computed radiography
NDT Level III Consulting Services:
NDT set up @ Customer location:
Quality NDT Services With in-house experienced NDT level III's can help you in setting up new facilities and can assist you in the following