The existing nondestructiontest (NDT) methods that have found wide application in power industry and others fields fail to solve the problem in question. These methods are directed toward the search for the developed defects which is intolerable in view of considering the problem of equipment reliability in terms of personnel safety.

Today, all leading diagnostic centres else where in the world are concerned with the problem of measuring mechanical stresses on designs in operation. However, no efficient and practicable inspection method has been suggested so far.

Now, a conceptually new method of diagnostics has been developed in Russia and is successfully implemented in the power industry, oil-gas and other areas based on metal magnetic memory.

The major advantages of the new magnetic diagnostic method as compared to known world analogs are as follows:

• no need in special magnetizing devices;
• determination of stress concentration areas during inspection;
• no metal dressing or any other preparatory actions on the surface to be examined is required;
• possible use of small size devices and independent power supply.

The new diagnostic method is most efficient for life estimation of basic components. Using stress concentration areas where corrosion, fatigue and creep are most intense, and applying concrete criteria described in special guides, the value and direction of future crack propagation can be determined starting from the metal structure level. Until recently, observing initiation and propagation of metal crack from applying load up to appearance of microcrack nucleation site was a prerequisite of laboratory experimentators only.

The diagnostic method can be used in power industry, oil-gas, chemical, metallurgy, machine-building, ship-building, railway transport and other industries.

The new magnetic diagnostic method has passed comprehensive approbation and proved to be efficient at a number of power stations in Russia, Ukraine, Bulgaria, Australia, Poland and India.

Energodiagnostika with Elektrim India Limited executed the following jobs on Indian TPS in 1993-1995: life estimation study of rotors of turbine on the karadi TPS and on the Barauni TPS, life estimation study of elements of turbine on the Bhatinda TPS, diagnostics of elements of boiler on the Gandhinagar TPS and on the UkaiTPS.

The instrumentation has no analogs and is commercially manufactured by the "Energodiagnostika", Russia, Moscow.
Concrete inspection techniques for boiler heating surfaces, drums, bends and pipe welded joints, turbine rotors and cylinders are agreed upon with Boiler Inspection and Ministry for Fuel and Energy of Russia.