The UT-Phased Array Technique is a process wherein data are generated by controlled incremental variation of the ultrasonic beam angle in the azimuthal or lateral direction while scanning the object under examination.
This process offers an advantage over processes using conventional search units with fixed beam angles because it acquires considerably more information about the reflecting object by using more aspect angles in direct impingement.
The UT-amplitude time-of-flight analysis technique utilizes multiple search units in pulse-echo, transmitter-receiver, or tandem configuration. Individually selectable parameters control the compression of the A-scan information using a pattern-recognition algorithm, so that only the relevant A-scan amplitudes are stored and further processed. These raw data can be displayed in B-, C-, and D-scan (side, top, and end view) presentations, with selectable color-code increments for amplitude and fast zoom capabilities. This operating mode is most suitable for detection purposes. A two-dimensional spatial-filtering algorithm is applied to search for correlation of the time-of-flight raw data with reflector-typical time-of flight trajectories.Tandem sizing and analysis uses techniques similar to pulse-echo but provides images that may be easier to interpret since the specular reflections from flaws oriented perpendicular to the surface are used.
The FloormapVS2i floor scanner is a computerized MFL system designed to detect, size and map under floor corrosion on above ground storage tanks. The FloormapVS2i magnetic flux leakage (MFL) floor scanner comes with up-graded magnets to improve corrosion detectability and sizing on thicker materials, faster data capture with a custom designed micro controller and all new software. The VS2i contains significant improvements in terms of defect positioning, electronic data processing and software manipulation.
Key Features:
Applications:
Advantages of ECT
Advantage of RFET
ADVANTAGES
RESULTS
Application of IRIS
Advantages
Air Fin Coolers.
Magnetic Particle Examination method may be applied to detect cracks and other discontinuities on or near the surfaces of ferromagnectic materials.
Prior to magnetic particle examination, the surface to be examined and all adjacent areas within at least one inch of the testing area shall be dry and free of all dirt, grease, scale, welding flux and spatter or extraneous matter that may interfere with the examination.
On completion of the above operation, the magnetic field may then be applied to the surface of the part to be examined. The flourescent magnetic ink shall then be applied to the weld area. At least two separate examinations shall be performed on each area. During the second examination the lines of magnetic flux shall be approximately perpendicular to those used during the first examination.
The magnetic field is to be “ON” during all examinations and during the application of the magnetic ink. At no time shall examinations be examined 135 oF in temperature.
Indications will be revealed by retention of magnetic particles. All such indications are not necessarily imperfection, however, since excessive surface roughness, magnetic permeability variations (such as the edge of heat affected zones) etc, may produce similar indications. If indications are believed to be non-relevant, each type of indication shall be explored to determine if relevant linear discontinuities are present.
A preferred NDE Method for examination of butt welds, castings and assemblies such as aircraft structures and steel bridges using either an x-ray or a radioactive isotope. Its application calls for skill particularly in interpretation, and it is accepted in most industries as a reliable and essential inspection tool and leaves clients with a permanent record of inspection.
Equipment used
SENTINEL Model 880 Delta
The detection of the surface cracks and flaws by the use of the dyes. These may be flourescent or colored. The dye contains wetting agents to make them flow evenly into very fine cracks. Depending on the type of defect sought, the dye is left to penetrate for a period of from 5 to 10 minutes. Surface dye is by then removed and a developer applied. Where there is crack, dye is drawn out by the developer leaving an easily visible indication above the crack.
Purpose:
To detect severity of open to the surface discontinuities on welds of:
Equipment used
Ultrasonic Examination of metals consists of passing sound waves through the material until they are reflected by an interface. If a flaw is present, or if an echo is picked up from the bottom surface of the materials, and indication is reflected on the instrument. ULTRASONICS is used in examining forged materials and some configuration of welds. Interpretation is done at the same time by the operators and for this reasons only highly skilled operators can be allowed to use the equipment if reliable results are to be obtained. Apart from detection, ULTRASONICS can readily be use to measure thickness of materials.
An important function that shop inspection (stationary and rotary equipment), site inspection and pre shipment inspection on Pipeline Systems (Oil, Gas & Liquefied Petroleum) can be carried out satisfactorily only by trusted and experienced Inspectors whose integrity and competence are beyond doubt. The reliability and overall normal performance of inspection jobs are products of careful selection of the Inspection Company possessing an excellent and untarnished reputation and likewise, the effective intervention of a cohesive team of inspectors.
The UT-amplitude time-of-flight analysis technique utilizes multiple search units in pulse-echo, transmitter-receiver, or tandem configuration. Individually selectable parameters control the compression of the A-scan information using a pattern-recognition algorithm, so that only the relevant A-scan amplitudes are stored and further processed. These raw data can be displayed in B-, C-, and D-scan (side, top, and end view) presentations, with selectable color-code increments for amplitude and fast zoom capabilities. This operating mode is most suitable for detection purposes. A two-dimensional spatial-filtering algorithm is applied to search for correlation of the time-of-flight raw data with reflector-typical time-of flight trajectories.Tandem sizing and analysis uses techniques similar to pulse-echo but provides images that may be easier to interpret since the specular reflections from flaws oriented perpendicular to the surface are used.
Inspection & Expedition
Resident inspection
Post weld heat treatment (PWHT) is a controlled process in which a material that has been welded is reheated to a temperature below its lower critical transformation temperature, and then it is held at that temperature for a specified amount of time. It is often referred to as being any heat treatment performed after welding; however, within the oil, gas, petrochemical and nuclear industries, it has a specific meaning. Industry codes, such as the ASME Pressure Vessel and Piping Codes, often require mandatory performance of PWHT on certain materials to ensure a safe design with optimal mechanical and metallurgical properties.
The need for PWHT is mostly due to the residual stresses and micro-structural changes that occur after welding has been completed. During the welding process, a high temperature gradient is experienced between the weld metal and the parent material. As the weld cools, residual stress is formed. For thicker materials, these stresses can reach an unacceptable level and exceed design stresses. Therefore, the part is heated to a specified temperature for a given amount of time to reduce these stresses to an acceptable level. In addition to residual stresses, microstructural changes occur due to the high temperatures induced by the welding process. These changes can increase hardness of the material and reduce toughness and ductility. The use of PWHT can help reduce any increased hardness levels and improve toughness and ductility to levels acceptable for design.
The requirements specified within various pressure vessels and piping codes are mostly due to the chemical makeup and thickness of the material. Codes such as ASME Section VIII and ASME B31.3 will require that a specified material be post weld heat treated if it is over a given thickness. Codes also require PWHT based solely on the micro-structural make-up of the material. A final consideration in deciding the need for PWHT is based on the components’ intended service, such as one with a susceptibility to stress corrosion cracking. In such cases, PWHT is mandatory regardless of thickness.
Flaws such as pinholes, air bubbles, inclusions, cracks, void and thin spots can occur in a wide range of coating material used in industry. A pinhole although small can cause extreme damage by permitting corrosive materials to reach the base material. Lack of continuity of coating causes premature failure, which can be very expensive to repair and lead to possible stopages in production. In certain circumstances, an air pocket can represent a subtantial portion of the total thickness, and thus cause a weak point, even though the coating is continuous.
High voltage Holiday Detectors are, in principle, insulation testers used to indicate a fault in the non-conductive coating under test be generating a spark which triggers audible and visual alarm.
The Elcometer 105 DC Holiday Detectors provide a versatile, convenient, fast, dry method of checking thick coatings for pinholes, cracks, thin spots or flaws. (Method conforms to ASTM G62-Part B)
Range of probes and accessories enable operation on test areas including the inside and outside of pipe, large surfaces and long reach applications.
With PMI the alloy composition and thus, the identity of materials can be determined. When the material certificate is missing or unclear and the costumer wants certainty about the composition of a material, PMI is the solution. PMI is particularly used for high-quality metals like stainless and high alloy metals.
Cathodic Protection is the most widely applied electrochemical corrosion control technique. This is accomplished by applying a direct current to the structure such as pipelines, storage tanks, pressure vessels and others which causes the structure potential to change from the natural corrosion potential to a protective potential in the immunity region.
The required cathodic protection current is supplied by sacrificial anode materials or by an impressed current system. Most metals in contact with an aqueous environment having a near neutral pH can be cathodically protected
Hardness is the measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. Macroscopic hardness is generally characterized by strongintermolecular bonds, but the behavior of solid materials under force is complex; therefore there are different measurements of hardness: scratch hardness, indentation hardness, and rebound hardness.
Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity.
Rebound hardness, also known as dynamic hardness, measures the height of the “bounce” of a diamond-tipped hammer dropped from a fixed height onto a material. This type of hardness is related to elasticity. The Rebound Hardness Test measures hardness of materials in terms of the ‘height of rebound of the indenter’ dropped on the materials surface with the help of a special device known as the ‘Scleroscope’. Put in other words, the Scleroscope measures hardness in terms of the elasticity of the material, where the hardness number is dependent on the height to which the hammer rebounds. The harder the material, the higher is the rebound.
Two scales that measures rebound hardness are the Leeb rebound hardness test and Bennett hardness scale.
The Equotip3 metal hardness testers use the dynamic Leeb rebound technique invented by Proceq. Hardness tests according to this Leeb method are particularly quick and easy to perform.
Post Weld Heat Treatment (PWHT) reduces the residual stresses formed during welding. It also restores the macro structure of the steel. Mandatory in high pressure applications, constructors have to strictly follow PWHT requirements to avoid component failures
PWHT eliminates the effects by heating, soaking, and cooling the weld area in a controlled manner to temperatures below the first transformation point, giving the macro structure sufficient time to readjust to its original state and removing the residual stress.
A. On-Service Inspection (OSI): This inspection is performed while the tank is still in service.
Inspection Scope mainly involves detailed visual examination on exterior of the tank done by an authorized API-653 inspector and ultrasonic thickness measurement of the shell & roof plate including all nozzles.
B. Out of Service Inspection (OOSI): This inspection is performed while the tank is not service.
Our authorized API-653 inspector conducts a visual inspection on exterior & interior of the tank and assures the quality and completeness of the nondestructive examination (NDE) results.
Nondestructive examination mainly involves MFLT on tank bottom & annular plates, ultrasonic thickness measurement of the shell & roof plate including all nozzles.
C. Reports:
Inspections shall be documented in a comprehensive report containing:
