Typical application cases I

1. Overviews          
The detection in service of non-ferrous and ferrous metal pipe (such as brass and titanium tube, stainless steel tube, boiler tubes) for heat exchanger. The function of heat exchanger is to deliver energy and consists of a large number of tubes in its interior. Due to long-term under the action of alternating stress and corrosion medium, the tubes are often corroded and abrased, so a regular inspection for internal heat exchange tubes is the important measure to ensure safe operation of the equipment. Our vortex flaw detection equipment has been widely used in equipment maintenance of domestic large nuclear power plant such as Daya Bay, ling-ao, Qin-shan, red river, etc. Executive standard: 883-2004 the technology guide of far field vortex inspection for power plant feed water heater in service ferromagnetic steel tube. JBT 4730.6 2005 pressure bearing equipment nondestructive testing, vortex testing. JB-T 11259-2011 nondestructive testing instruments-multi-frequency vortex detector.
In-service testing site
2. Method of application    
Usually, the heat exchange tube can be divided into two categories from the material ,one is non-ferromagnetic materials such as austenitic stainless steel, aluminum alloy, titanium alloy and copper alloy, etc. For the materials, conventional vortex testing technology is mature in high speed, high sensitivity, defect signal analysis method. The multi-frequency vortex testing is given priority to, it imposes two or more than two alternating exciting currents on the same test coil, and detects, magnifies respectively, and then feeds into together mix processing unit, vector to add and subtract. When it is used for pipe inspection, can accommodate well the detection sensitivity of steel tubes inside and outside wall defect, and multi-frequency vortex also can effectively inhibit shakes, swing and eccentric and support plate signal between part and probe in test. Another kind is ferromagnetic materials, such as carbon steel and low alloy steel, etc. Far field vortex testing is a new kind of pipeline inspection technology and has a potential development prospects, it can solve the problems such as rapid testing and thickness measuring in service of steel tube used widely in electric power and petrochemical industry.
Regular vortex internal break probe
Far field vortex probe
Detecting the far field vortex signal at the scene
3. Superior characteristic               
•The surface of the tested steel pipe don't need to clean;
•Probe does not contact with surface of steel tube, the clearance changes between probe outer diameter and pipe inner diameter have little impact on the test results, the maximum allowable clearance is 30% of steel tube inner diameter, the best clearance is less than 15 % of the inner diameter of steel pipe;
•With the same sensitivity when testing the corrosion pits of steel pipe inner surface and outer surface;
•With high detection sensitivity for testing of uniform thinning, gradual thinning and eccentric wear thinning;
•Whether the probe detection speed is uniform, do not affect the detection result;
•The gas and liquid mediums in steel pipe do not affect the test results;
•Testing equipment is small in size, light weight, easy to flexible application in site.
4. Recommend instruments