Ndts India (P) Limited.

Eddy Current Testing (ECT) works on the principle of electromagnetic induction. In ECT a probe is excited with sinusoidal alternating current to induce eddy current in an electrically conducting material such as stainless steel, aluminium etc. The change in coil impedance that arises due to distortion at regions of discontinuities and associated magnetic flux leakage is measured. This is a surface technique and can readily detect very shallow surface defect and sub-surface defects. ECT is a simple, high-speed, high sensitive, versatile and reliable NDT technique and is popularly used in many engineering industries.

Thickness measurement at elevated temperature is a special category. Standard transducers are not designed to withstand elevated temperatures and will get damaged/destroyed due to varying thermal expansion coefficients of the materials used to construct them. Variation in material temperature affects sound velocity and accuracy of thickness measurements. We use Electro Magnetic Acoustic Transducer (EMAT) equipment without couplant to accompany this task.

We offer this service using temate TG-IS (B) which is a redesigned FST-GAGE or Fast Scanning Thickness Gage, first introduced in 1994. FST-GAGE was developed by Electric Power Research Institute (EPRI) and Babcock & Wilcox (B&W) specifically to scan boiler tubes and provide a continuous measurement of tube wall thickness.

The system works on Electro Magnetic Acoustic Transducer (EMAT) technique providing accurate thickness (with accuracy of +/- 0.127mm) readings with none or minimal tube surface preparation. The probe with integrated encoder and light indicators (for fast visual alert to the operator) is manually scanned along the boiler tube while the system records the thickness & alarms if the tube is below a pre-programmed threshold or other defect conditions are triggered. The system saves a complete record of each tube & the whole boiler for later post analysis & tracking.

Apart from detecting wall loss the system is capable of detecting hydrogen damage, pitting & caustic gouging (by measuring signal attenuation) which is not detected with conventional means. It works on carbon steel and clad tubes. Tube thickness ranges from 3.8mm to 12.7mm & the minimum tube diameter requirement is 22.2mm, the tube surface can be oxidized, rough or pitted (scale-free). The technique permits 100% inspection of the boiler instead of spot checking at up to 15cm/s of scanning speed. The boiler mapping tool permits easy visualization of boiler walls with results of inspection for fast analysis and interpretation.

We offer ultrasonic pigging (by using In-line inspection tool EasyPig™ UT) and MFL Pigging (by using In-line inspection tool EasyPig TM) services for small diameter (4”, 6” & 8”) field pipelines with the help of M/s. Intron VTD, Russia

RVI(boroscopy/Videoscopy) is used to visually inspect plant components for surface defects, general condition, degradation, blockages & foreign materials. It can be used as standalone inspection or as a complement to other NDE techniques, such as eddy current, ultrasonic or x-ray, in order to qualify unclear signals or pinpoint where a more thorough inspection is needed.

We offer a turnkey inspection solutions, whether it is inspecting high energy piping, performing a loose part retrieval or diagnosing an operational problem, we bring the right equipment to visually inspect (or retrieve) it, record it, and report it back to you.

PEC is an advance electromagnetic inspection technology which majorly detect remaining wall thickness under insulation in ferrous material. It uses square pulse signal to induced eddy current which can penetrate more deeply in magnetic material than conventional Eddy Currents. PEC can measure thickness through all insulation materials, coatings, fixed chicken wire, concrete, re-bars, corrosion product, stainless steel sheeting, aluminium sheeting, water marine growth, blistering scabs, through metallic mesh.