HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Title: HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT BY PRESSURISING THE TUBE(38.1MM OD) FROM INSIDE WITH SPECIAL FIXTURING ARRANGEMENT Company Name: Larsen & Toubro Limited, Heavy Engineering Division, Hazira Manufacturing Complex, Dist:Surat Tel:0091 261 2805353 Fax:0091 261 2805050 Authors: S P Ghiya J L Songhela N S Choksi Date: 10th October, 2010 Location: Dubai

Products Reactor Column Regenerator Steam Generator EO Reactor Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) Products Reactor Column Regenerator Steam Generator EO Reactor End Shield PP Reactor Reactor Product Splitter

Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Introduction Leaks are special types of defects which can have a major importance in systems where they have influence on safety and performance. Many objects will have a reduced reliability if they contain leaks Leak testing is a non destructive examination method which is used for detection and localisation of leaks and for measurement of leakage in systems

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT In principle two methods are applied for leak testing and localisation of leaks, the "Vacuum method" and the "Overpressure method". At the "Vacuum method" the object to be examined for leaks is evacuated and sprayed from the outside with a search gas, in this case Helium. The gas enters through any leaks present in the object and is detected by a sensor connected to the leak test instrument At the "Overpressure method" the object to be examined for leaks is filled with a search gas, Helium, under slight overpressure. The search gas escapes through any leaks present to the outside and is detected by a detector probe. This detector probe is in most cases called a "sniffer" acting as a gas sampling probe.

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Leak rates down to 10-10 mbar l / s can be detected Both objects with vacuum or overpressure can be examined the objects can be examined during operation The examination can be performed fast and effective Non poisonous, non explosive and inexpensive gasses are applied Leaks can be detected in due time to prevent safety or operational hazards Leaks can be detected in due time to prevent unplanned and expensive shut downs

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT IBW is mainly done to prevent accumulation of process fluid between the gap of outer surface of tube and tube sheet hole.

Vacuum method - Hood test Vacuum method - Tracer probe test HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Vacuum method - Hood test Vacuum method - Tracer probe test Overpressure method - Hood test Overpressure method - Bombing test Overpressure method - Sniffer test Helium Leak Test, Vacuum Method, Hood Test

Vacuum method - Hood test Vacuum method - Tracer probe test HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Vacuum method - Hood test Vacuum method - Tracer probe test Overpressure method - Hood test Overpressure method - Bombing test Overpressure method - Sniffer test Helium Leak Test, Vacuum Method, Tracer probe test

Vacuum method - Hood test Vacuum method - Tracer probe test HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Vacuum method - Hood test Vacuum method - Tracer probe test Overpressure method - Hood test Overpressure method - Bombing test Overpressure method - Sniffer test Helium Leak Test, Overpressure Method, Hood test.

Vacuum method - Hood test Vacuum method - Tracer probe test HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Vacuum method - Hood test Vacuum method - Tracer probe test Overpressure method - Hood test Overpressure method - Bombing test Overpressure method - Sniffer test Helium Leak Test, Overpressure Method, Bombing test.

Vacuum method - Hood test Vacuum method - Tracer probe test HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Vacuum method - Hood test Vacuum method - Tracer probe test Overpressure method - Hood test Overpressure method - Bombing test Overpressure method - Sniffer test Helium Leak Test, Overpressure Method, Sniffer test.

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Heat Exchanger — Vertical View

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Inner bore weld leak tested using Helium lwith following parameters. Tube Sheet details: 33.88 hole dia * 180mm thick * 5576mm dia Tube Sheet material:: SA 182M-304H Tube Details: 38.1mm OD * 2.11 thick * 5820mm long* No of tubes: 10696 tubes Material: SA213 M-304H individually.

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT 180mm Tube sheet Tube

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Tube # Tube sheet welding using inner bore welding scheme

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Cross section of tubes, welded with tube sheet

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Heat Exchanger fabrication under progress-Vertical assembly

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Verification of Probe size and its functioning on mock up

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Helium Leak Testing Equipment

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Tube fit up/ welding /visual/ ferrite testing in progress in vertical condition

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Tube fit up checking in progress in horizontal condition

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Tube sheet View from Bottom Side

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Top view from tube open end…..mock up work for tube # tube sheet welding

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Tube # Tube Sheet joint Inspection Testing Requirements Fit up-Inspection Weld Visual Inspection (Inside & Outside) PT of completed weld (Inside & Outside) Ferrite Check ( From outside only ) Helium Leak test (After each tube welding) Pneumatic Test Hydrotest

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Helium Leak Testing Sequence Isolate joint from inside by providing leak proof fixture as shown in fig. Pressurize helium with 5 Psi ( 0.35 Kg / Sq. Cm) to 10 Psi ( 0.703 Kg/ Sq.Cm) Hold the pressure for minimum 30 Seconds Check the leakage from the other side with snifter probe of Helium test equipment Repeat the exercise for the complete row In case leak is noticed, repair the weld , before proceeding to the next raw Preparedness: Total twenty such fixtures were made and connected them through a manifold This arrangement enabled us to perform this test at a time in multiple joints in a row

Automation in PT evaluation of internal weld for Small Bore (4” to 12”), having longer pipe (up to 2000 mm.) HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Helium Leak Test Probe Outlet connecting to MSLD Tube Tube Sheet Face

Helium leak test probe HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT 3-D Model of Helium Leak Test Probe Hole Probe Handle for tightening O-Rings Handle for holding

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Probe Probe with Helium “standard leak”

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Weld Visual Testing in Progress

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Weld Bead Finish Through Video Scope , Displayed on Computer Terminal

HELIUM LEAK TEST OF INNER BORE WELDS OF TUBE#TUBESHEET JOINT Conclusion : This technique of inspecting flaws in Inner Bore Weld of small diameter and inaccessible from outside has provided immense confidence to all NDT personnel involved including customer, ensuring defect free weld quality.

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