Abstract

This document describes the requirements for eddy current testing of heat exchanger tubes made of ferromagnetic materials using internal flow sensors with DC bias magnetization. The test is typically carried out on installed heat exchanger tubes, but can also be used on non-installed, isolated tubes for quality assurance prior to installation. The test can be carried out both directly after manufacture and for operational testing during the use phase. The aim of eddy current testing as defined in this document is to detect reductions in wall thickness originating from the inside or outside of the pipe wall and to determine this reduction in wall thickness as a percentage of the nominal wall thickness. Typical causes of these wall thickness reductions are corrosion, erosion and chemical erosion. Furthermore, deformations (dents) can be detected. Cracks can only be detected to a limited extent using the method described here. This document is applicable for the use of special internal flow sensors in absolute or differential circuits with a device for generating a DC field bias magnetization in the form of magnetization coils or permanent magnets. It is not applicable for the use of scanning, segment, rotating and array probes.

Begin

2024-04-11

Planned document number

DIN 54018-3

Project number

06236700

Responsible national committee

NA 062-11-13 AA - Electrical and magnetic test methods  

draft standard

Non-destructive testing - Eddy current testing for testing of heat exchanger tubes from the inside - Part 3: Tubes from ferromagnetic material - Magnetic bias method
2025-01
Order from DIN Media