Non-Destructive Testing (NDT) Services

ITS AN NDT methods for boiler and heat exchanger
equipment in the petrochemical industry to supplement major turnaround inspections The petrochemical industry depends on many heat exchangers and boilers for efficient operation. As these
components consist of many tubes tightly held together, they are very hard to inspect visually or with normal
ultrasonic or radiographic thickness measuring techniques. Inspections used to take two to three weeks to assess
the condition of a boiler or heat exchanger

• IRIS (Internal Rotary Inspection System): The internal rotary inspection system (IRIS) is an ultrasonic non-destructive testing (NDT) technique used to inspect pipes and tubes. (IRIS) is based on the principle of measuring thickness using ultrasonic waves.The (IRIS) method is mostly used for inspection of carbon steel tubes and is sometimes used in non-ferromagnetic tubes for defect verification. The method is very accurate for thickness measurement as well as detecting ID and OD pits.
• ECT (Eddy Current Testing): ET can be defined as an electromagnetic nondestructive examination method in which small electrical currents are induced in a material, and any changes in the flow of these currents in the material are detected by a nearby coil for subsequent electronic processing and presentation. Its use for the examination of welds for surface or subsurface discontinuities is only one of the many applications .Eddy Current technique is a technique that is adapted to the inspection of small-bore nonferromagnetic heat exchanger tubes such as stainless steel, titanium, copper, brass, copper-nickel alloys, inconel,etc.
• Remote Field Eddy Current Testing (RFT): Remote Field Eddy Current Inspection is an electromagnetic technique that is well adapted to the inspectionof small-bore ferromagnetic tubes such as carbon steel. In industry, it is now the method of choice for boilers and heat exchangers tube examination because of its low frequency (typically 50-1000Hz) .It is primarily employed to detect and assess flaws, corrosion, and other defects in the walls of these tubes without the need for direct contact with the interior surface of the tube.
  RFT is particularly useful in industries like oil and gas, petrochemical, and power generation, where the integrity of such tubular structures is critical.
• NFT (Near Field Testing): Near field testing (NFT) is a non-destructive testing (NDT) technique used for inspecting and evaluating materials, components, or structures, particularly in applications where close proximity to the test object is required.Unlike some other NDT methods that rely on the propagation of waves over long distances, NFT operates in the near field region, which is close to the surface of the material or structure being tested.

PAUT is used for sizing, imaging, and flaw detection in much the same manner as standard ultrasonic methods. This technique is in use mainly in the piping, vessel and tank industries. Specific techniques and codes are still being developed for the use of PAUT in the structural and bridge industries. PAUT is commonly used to supplement, or is performed in lieu of, radiographic or traditional contact ultrasonic inspection

The TOFD technique utilizes two angle beam probes placed in a transmitter- receiver position, one on each side of a weld. The transmitter emits a longitudinal wave that is picked up by the receiver. An A-scan display will show an indication from a surface traveling wave (called the “lateral wave”) and indications from the back wall. Between those indications will appear indications from any discontinuities that are present. Some sort of imaging is also usually employed. TOFD can simultaneously detect and size defects, and is among the most accurate techniques for sizing cracks. TOFD does have limitations, (e.g. limited near surface resolution capability) and is generally performed in conjunction with another technique of ultrasonic examination.

Long range ultrasonic testing (LRUT), also known as guided wave ultrasonic testing, is a fast and cost-effective method for inspecting long lengths of pipe.Hundreds of metres of pipe can be screened in one day from one single location and the technique can inspect 100% of the pipe wall. LRUT can be performed on piping that is in operation, insulated and buried, and in areas that are difficult to access such as those at high elevations. The method can therefore save time and money that would otherwise be spent on excavation, insulation removal and scaffolding.

Short Range Ultrasonic testing also commonly known as SRUT is one of the Ultrasonic test methods wherein the ultrasonic waves are transmitted in the form of pulsed guided laminar waves using special purpose ultrasonic probes. When laminar waves hit discontinuities they are mode converted and the reflection of the waves are detected by the transducer

Pulsed Eddy Current technology is based on electromagnetics and provides average wall thickness values over the probe footprint area. It measures and compares the percentage variation in average wall thickness throughout an object. Pulsed Eddy Current can be effectively applied for corrosion detection and monitoring on pipes and vessels made of carbon steel or low-alloy steel without making contact with the steel surface itself. PEC technology allows measurements to be made through insulation

Magnetic Flux Leakage Inspection (MFL) is a non-destructive testing (NDT) method used to detect and evaluate corrosion, pitting and wall loss in metal storage tanks and pipelines.In tank floor inspection, the tank floor is swept with the MFL tool. The area is flooded with magnetic flux and the earth magnets are used to temporarily magnetize the steel while changes in the magnetic field are recorded and analyzed. If the magnetic field is distorted, there are internal or external defects, such as pitting or corrosion, and this distortion or “leakage” can be measured by the sensors. Technicians proceed to mark the areas that need to be verified by visual inspection and ultrasound. The results obtained from the MFL inspection can be reported and used to establish an existing baseline for the equipment or to determine remaining wall corrosion