Magnetic Tomography Method (MTM)

The Advance technology of Non - Contact Magnetic Tomography pipeline survey enables the survey of pipelines of all configurations, underground and submerged, while the pipeline remain working at normal operation condition without preparation process needed.

With the capability of detects and measure level of stress, detect defect at any direction, defective insulation in single pass, Magnetic Tomography Method, approve to be the perfect solution in order to achieve high reliable survey results without interfering operational process.

The locations of defects are defined within an accuracy of +/- 1.5m thus facilitating further investigation or repair.
The final report defines the degree of danger of defects and recommends maximum safe working pressures and also the length of time it is safe to operate defective sections of pipe at those pressures.
The system can be used to survey trunk pipelines (across any terrain including water) and service pipelines within cities. Accuracy is not affected by either the close proximity of other pipelines or city.



Identifiable Defects
The following internal and external defects, their parameters and their location can be accurately defined:
Crack-like defects in any orientation (laps, scabs, scratches, stress corrosion, cracking and exfoliation)
Weld defects (laps, pores, cracks, lack of fusion, lack of penetration, displacement, metal flakes, and residual thermal stress within the heat
Compression marks, corrugations, scores, out of roundness and changes in wall thickness caused by corrosion pits and fill form corrosion
Loss of metal including internal and external corrosion defects of any nature
Delamination
Sections with deviations of a level of stress deformed conditions caused by, for example, sagging, landslips, washouts or transitiosunder roads.
Local corrosion under scaled insulating coating
Indents
Buckles
Deviation from the specified laying axis

Specification:

Wall thickness measurement range From 3mm (maximum is not limited)
Pipeline diameter D restrictions 56 = D = 1420 mm
Speed range 2-5 m/s
Maximum pipeline pressure Unlimited
Minimum pipeline pressure 0.02 MPa
Minimum turning radius of pipe Unlimited
Minimum inside diameter of pipe Unlimited
Overall dimensions of magnetometer 200200750 mm
Magnetometer Mass 4.7 kg
Minimum length of a pipeline required for one pass Unlimited and does not depend on seasons or pipeline condition
Completeness of the control along the extent of installation 100 %
Admissible deviation from the pipeline axis On distance not more than 3 x D (D = pipeline diameter)
Admissible distance between the magnetometer and the pipeline 20 x D
Maximum measurement step frequency along the longitudinal axis 0.25 m
Anomaly positioning accuracy 1.5 m
Accuracy of angular location of anomalies 20
Error of odometer (distance transducer) Not more than 5 %

Tolerance and Accuracy
Minimum length of detectable defects: >10mm
Opening of detectable defects: >300 microns
Depth of detectable defects: >5% of the pipe wall thickness
Measurement tolerance:
Crack length: +/-20%
Crack depth: +/- 30%
Wall thickness loss: <25%
Detection rate: 2m/sec max
Location and orientation of defects: No restriction
Process Limitations
Operating temperature: None defined. Has been used at -50 to + 63 deg C
Pipeline diameter: 56mm to 1420mm
(based on actual survey experience to date. Extensions to either stated limit may be possible)
Pipe wall thickness: 2.8mm to 22mm
(based on actual survey experience to date. Extensions to either stated limit may< be possible)
Detection rate: 2m/sec max
Distance between magnetometer and pipeline: 15 x pipe dia max
(refers only to measuring pipeline depth and axis deviation)
Cannot guarantee the detection of defects which do not cause a change in the
level of stress deformed condition i.e. blow holes, pitting
* Petronesia Benimel is the only legal license agent in Indonesia to provide this survey in association with Transkor Asia Sdn. Bhd.