Sop.006 Eddy Current Procedures for Tube Inspection Hocking

INTEGRITY & QUALITY DIVISION CORROSION & INSPECTION DEPARTMENT

EDDY CURRENT PROCEDURES FOR TUBE INSPECTION

SOP.006 Issue 1 Revision 0

Date: 1st JUNE, 2003

WRITTEN BY: Brad Parkin

NDT Specialist

REVIEWED BY: Mahdi Al Marzouqi

HC&I

DISTRIBUTION LIST EDDY CURRENT PROCEDURES FOR TUBE INSPECTION (HOCKING)

SOP.006 Issue 1 Revision 0

CONTROLLED COPY HOLDERS

COPY

HOLDER

1

HC&I

2

SPIE

3

Admin. Controller

SOP.006 Issue 1 Revision 0

Page 2 of 6

EDDY CURRENT PROCEDURES FOR TUBE INSPECTION 1.

INTRODUCTION

1.1

This procedure is written to describe the following activities when carrying out eddy current examination of non-ferrous tube materials used within the ADGAS LNG complex and associated areas to determine the useful working life (remaining) of Heat Exchangers tube material using the Hocking-Phasec D62 System.

1.2

The System complements the previously utilized Magnaflux system and can be mainly used mainly as a replacement and also to test titanium tubes not previously covered by that system.

1.3

Interpretation of results now being computerized, and the system itself more versatile, this procedure (Hocking) being favourable on site.

1.4

Contents: · Calibration · Testing · Interpretation

CONTENTS SECTION

TITLE

1.

CALIBRATION PROCEDURE FOR TUBE INSPECTION

2.

INSPECTION PROCEDURE

SOP.006 Issue 1 Revision 0

No. of Pages 1.5

1

Page 3 of 6

EDDY CURRENT CALIBRATION PROCEDURE FOR TUBE INSPECTION

SECTION 1

1.1 1.2

1.3 1.4

1.5

2.1 2.2

2.3

2.4

A calibration tube (as per Figure 1) of the same material, diameter and thickness of tubes to be tested shall be used. The probe(s), transport system, osillographic recorder, E/C recording unit and laptop computer shall in this instance be specific and limited to the Hocking supplied system only. · Recording Unit = Hocking Phasec D62 · Computer = P=III Lap-Top (Compaq) · Oscillographic Recorder = OR 100E/OR 300E · Transport System = Trigger activated (using air) · Probe type(s) = 10 Khz or as required. If for any reason the above components are replaced or repaired, the calibration procedure shall be repeated in every case. When the equipment has been switched off the calibration procedure shall be repeated once the machine has been switched on again. Equipment to be switched off when unattended and placed in a safe secure area. The chosen calibration tube shall be set horizontally with the through - hole at the 6 o’clock position. Probe to be moved back and forth over the through hole so that the vector point is moved from the centre point diagonally right at 45o, refer to item (h). The probe shall be inserted into calibration tube to an excess of 25mm. Parameters to be set on recorder as required. Taking into note. ¨ Frequency ¨ Probe (logged as 1) ¨ Channel (logged as 1) ¨ Differential and persistence parameters ¨ Lo pass filter at 300 Hz ¨ Hi pass filter at ‘DC’ Note: Parameters may be recalled from ‘Freeze’ functions. Obtain balance by pressing “BAL” before checking the phase angle from reference standard check other signals by setting “GAIN”. Obtain signal from through hole (to be displayed on screen).

SOP.006 Issue 1 Revision 0

Page 4 of 6

2.5

Enter parameter adjustments (left menu key) with through hole signal set to 45o before exiting from record menu. 2.6 Ensure that Phase and Amplitude (and other references) are within the display screen, and then save settings. 2.7 Open “ARTIST” programme on LapTop and create new file or open existing file in work directory. 2.8 Go to calibration mode and set parameters to include all internal and external fault readings from calibration tube including hole reference point, record all signals from test calibration tube. 2.9 Carry out analysis (through hole first) then view and check calibration curve (Phase Curve). 2.10 Exit calibration mode when acceptable to parameters given and move to site for test/inspection of required/requested tubes.

SOP.006 Issue 1 Revision 0

Page 5 of 6

EDDY CURRENT INSPECTION PROCEDURE FOR TUBE INSPECTION

SECTION 2 1. 1.1 1.2 1.3 1.4 1.5 1.6 2.

PREPARATION Permit to work system to be adhered to. Ensure safe/accessible platform/work area to position equipment is available. Arrange 110V power supply and a compressed air supply available to area. Set up equipment and carry out calibration checks. Ensure correct probe cable supplied and fit cable stops. Always ensure tubes are dry. INSPECTION

2.1 2.2

A minimum of 2 operatives are required to perform test. Probe shall be blown down relevant tube by the compressed air applicator. 2.3 Test to be carried out during removal of probe from tube at steady rate (constant) approx. 1M/sec. 2.4 Results to be configured and accessed from LapTop and relevant programmes as per requirement. 2.5 Air retraction of probe should be set at 15 psi for 1M/sec withdrawal – Ref. (c). 2.6 At end of site test check calibration on instrument. 2.7 Recall work directly in “ARTIST” programme. 2.8 Row/Tube No. to be entered as per requirement. 2.9 Enable “RTA Analysis” and “Auto Score” functions. Note: Length of cable to be entered as per tube and inspection length. 2.10 Equipment to be balanced for every tube test. Changing Row No. as necessary and repeating tube test to completion of required scope of inspection. 2.11 Before final departure from test area check calibration again. 2.12 Document findings and report to respective Inspector.

SOP.006 Issue 1 Revision 0

Page 6 of 6