Wednesday, September 19, 2007

AUT - Time of Flight Diffraction on

TCR Engineering Services, as an NDT services company, routinely provide AUT using ToFD in India and Saudi Arabia. I wanted to give something back to the outstanding forum on and thought that one of the best ways will be to create a compilation of answers on ToFD that are so frequently asked on  I plan to update this thread as time permits so that we can all benefit from the collective wisdom of the contributors of this forum. Here are links and brief outlines to important discussions on Time of Flight Diffraction:


Sizing a Defect using ToFD

Contributor Suresh on writes:

However, over the last 20 years, TOFD has probably been used more in validations, round robin trials et cetera than any other NDT technique. From this, we have established that TOFD is probably the most accurate sizing technique for embedded defects presently available to the world. A recent test for a major oil company we did on some 30 rootcracks in thin walled material, which were compared to physical measurements after destructive testing showed a mean error on height sizing for TOFD of 0.27 mm with a standard deviation of 0.7 mm. The X-Ray results obviously did not give any height measurement. On the length measurement the accuracy of TOFD was 2.6 mm, with a standard deviation of 4.5 mm. For X-Ray the accuracy of the length measurement was -19 mm (undersized) with a standard deviation of 43.5 mm. By the way, X-Ray only revealed 55% of the cracks, whereas TOFD found 97%.


Demonstration of technique as per 2235-9

Contributor Ed Ginzel writes:

The method of sizing (vertical extent?) for CC2235-9 for examining pressure vessels with a thickness over 13 mm needs to be qualified (demonstrated).  It states in i)(3) Flaw Sizing. Flaws shall be sized in accordance with a procedure demonstrated to size similar flaws at similar material depths. Alternatively, a flaw may be sized by a supplemental manual technique so long as it has been qualified by the demonstration above.


Dead Zone Calculation

If I were to bet, this thread is the longest and most frequently asked question with respect to ToFD.

Tom Nelligan of Olympus NDT wrote:

Dead zone -- the interval following the excitation pulse in which potential exchoes are obscured by ringdown -- is a property of BOTH the probe and the instrument. The response of any transducer is highly dependent on how it its pulsed. Changing pulse energy, type (spike, square wave, or tone burst), and damping, as well as receiver gain and filtering, will have a significant effect on the excitation pulse ringdown envelope and hence on dead zone length. As others have suggested, your best approach is to simply measure it under your actual test conditions using appropriate reference blocks.


Ed Ginzel wrote

The "missed data" would be the dead zone. This is not actually a function of the wall thickness but instead, the ring time equivalent depth of the pulse. Frequency, probe spacing and angle used can all be factors. A simple calculator is provided as a download on to estimate the Dead Zone heights associated with TOFD setups.


Smallest detectable flaw using TOFD

Ed Ginzel once again has a truly informative posting where he mentions:

In clean low carbon steel I have “detected” pores on the order of 0.2mm diameter using a 5MHz TOFD. That is on the order of 5-6 times smaller than the wavelength! But when the same TOFD technique is applied to austenitic stainless steel with grain size on the order of 50-100 microns, the scatter makes it virtually impossible to detect anything but the largest of flaws. Grain size in chrome stainless steels are typical of this order of magnitude. (see

Properties of the materials tested (not just the alloy, since an alloy may be made in many forms of different grain sizes) and the purpose of the test will be critically important factors when considering the answer to your question. We can discuss “theoretical” limits to “detections”; but in UT (including and especially in TOFD) the response of the indication of concern over the background scatter noise from grain structure will be crucial. If you are expecting to RELIABLY “detect” flaws smaller than the grain size you will probably not be successful. The lateral wave will cause you problems at the lower end of thicknesses due to the dead zone (but I have seen shear wave TOFD used on 4mm wall in fine grained zirconium tubing). Thick sections (200-300mm) can also be tested by TOFD but accumulation of scatter increases with increasing soundpaths. In all cases the signal to noise ratio you can achieve will be the limiting factor for practical use of TOFD.


LoF vs. Slag when doing ToFD as per B31.3 in Piping

J. Mark Davis wrote:

LOF being a planar defect will tend to have a fast rise and fall time, and a short pulse duration. Slag is a volumetric defect and tends to have a slow rise and a long duration. Both defects can cause a beam redirection to the OD or the ID. Also, please realize that as with radiography, you can have several people look at a radiograph and make a slag or a LOF call, and sometimes not all will be in agreement. The same will hold true with UT and Phased Array. If the indication plots to the weld fusion line this probably is side wall lack of fusion. If the indication plots to the weld centerline, line this is probably Slag. Plus, you still analyze Rise and Fall and Pulse Duration.


Code Case 181

A lot people were searching for the actual code case 181 for ToFD. John O'Brien gave the URL to be as on the page


ToFD working Procedure

Rohit Bafna of TCR Engineering Services wrote:

We perform ToFD Services in India and Saudi Arabia and have a two member team. The first team member does the scanning (we are doing ToFD projects as per API 650 appendix u, Code case 181 for piping as well as code case 2235-9) while the second person has a manual UT machine with him.  Prior to the start of any project we give out two documents:

- Procedure for examination

- ToFD operating guide for inspectors which illustrates the step by step machine operations. It also includes the timelines of work during the day. For example we prefer to do the scanning in the morning and reporting in the afternoon.


I encourage others to update this posting/thread whenever they find any interesting article on ToFD. I hope over time, we can help other inspectors and fellow technicians learn and improve the usage of ToFD in the industry.

Tuesday, September 18, 2007

TCR Engineering approved by Halliburton

On completion of the audit conducted by Halliburton Company (with representatives from Houston, TX), TCR received the formal approval today. The approval notice said, “Based on our visit and audit, TCR Engineering Services has been approved and recommended for services performed for Halliburton.”


TCR is one of the select few material testing labs worldwide that have been approved by Halliburton. Suppliers and Vendors in India and elsewhere can count on the prompt and efficient services of TCR in the areas of Vendor Evaluation, Factory Audits, Third Party Inspection, Mechanical Testing, Chemical Analysis, Positive Material Identification (PMI), Non Destructive Testing (NDT including Automated UT using ToFD), Metallography, RoHS Compliance Testing, Corrosion Testing (including HIC/SSC), Failure Analysis Metallurgical Product Evaluation, Heat Treatment, Manpower Deployment, Training, Engineering Research and Consultancy.

Wednesday, September 12, 2007

NACE awards TCR the Best Laboratory Award

It gives me immense pleasure to inform you that NACE International (India chapter) has selected TCR Engineering Services (Navi Mumbai) as a recipient for the prestigious “Best Laboratory Award for 2007.”


The award ceremony is going to be held in Hotel Intercontinental in Mumbai on September 26. I’d like to share this joyous occasion with you and will be delighted if you can make your travel plans and come to India on that date.


TCR Engineering Services (TCR), a NABL and ISO 17025 accredited independent material testing laboratory in Mumbai, India undertakes a wide range of corrosion and stress corrosion test per ASTM, NACE or BIS. Tests can also be custom tailored to meet an individual client´s requirements.


TCR´s material testing laboratory in India determines inter-granular corrosion attack, weight loss corrosion, pitting corrosion, Sour gas service corrosion tests for sulfide stress cracking (SSC), CSC, salt spray, and hydrogen-induced cracking (HIC) for oil and gas, power, construction, shipping, petrochemical and process industries.

Tuesday, September 11, 2007

History of ASME B31

Author JohnBreen writes on eng-tips that that The ASME B31 Code for Pressure Piping includes specific “books” for various piping applications.  The Code is dynamic and the “sitting committees” work at keeping the Codes up to date with current standard industry practice – note, not “cutting edge”, not “trend setting”, not “latest and greatest" - rather current standard industry practice.   The B31 Codes are not the final word, only the latest word.


The history of the B31 Code is very interesting.  In 1926 the American Standards Associations, ASA (forerunner of ANSI) initiated project B31 to develop a pressure piping Code.  The resulting document, "American Tentative Standard Code for Pressure Piping, ASA B31.1 was issued in 1935.


During the long history of the B31 Codes various “book section” numbers were assigned for development.  Some of these documents were developed but not used as the work was pulled into another “book”.  Others of them were withdrawn when superseded by another document.  For completeness JohnBreen presented the following list of B31 “projects” and Codes:


B31.1 – Power Piping

B31.2 – Fuel Gas Piping, WITHDRAWN superseded by ANSI Z223.1

B31.3 – Process Piping, (formerly Chemical Plant and Petroleum Refinery Piping)

B31.4 – Liquid Hydrocarbon Transportation Piping (for example oil cross country pipelines)

B31.5 – Refrigeration Piping

B31.6 – Chemical Plant Piping, never issued as a separate document, folded into B31.3

B31.7 – Nuclear Power Piping, WITHDRAWN, superseded by ASME Code, Section III

B31.8 – Gas Transportation Piping (for example cross country gas pipelines)

B31.9 – Building Services Piping (for example office building hot water heating and air conditioning)

B31.10 – Cryogenic Piping, never issued as a separate document, folded into B31.3

B31.11 – Slurry Transportation Piping (for example cross country coal/water slurries)


Read more

Glass World Expo 2008

Services International are organizing an exhibition GLASS WORLD EXPO’08 EXHIBITION AND CONFERENCE  scheduled to be held at Bandra Kurla Complex Mumbai, India during 8th - 9th January 2008. Previous name of this Exhibition was Glass India & was held at Grand Hyatt Exhibition Ground, Mumbai, India.


Glass World Expo is the 7th in the series of highly successful exhibition. They have been doing this exhibition from last twelve years, in the year 2006 the exhibition attracted the record 1500 trade & very focused International & National visitors from the glass industry. Glass World Expo 2008 is going to mark the next successful step in glass industry with our satisfied exhibitors.



Saturday, September 08, 2007

Indian Institute of Metals in November

The Indian Institute of Metals (IIM) is the premier organization representing metallurgical engineers and professionals engaged in metallurgical industry, research and development and related activities.

IIM is organizing

(a) International symposium on Energy Related Materials on November 13, 2007,

(b) National Metallurgists Day (NMD) celebrations on November 14, 2007 and

(c) Annual Technical Meeting (ATM) during November 15-16, 2007


at Nehru Centre, Mumbai. A large number of persons from industry and R & D institutes in India are likely to participate in these events. During the NMD, eminent metallurgists of the country will be recognized by awards from the Ministry of Steels and by Indian Institute of Metals. The details of these programs are given at the web site


If anyone is interested in presenting a paper at this conference, please contact Rohit Bafna at TCR.

New Corporate Presentation from TCR - India's Leading Material Testing Laboratory

Friday, September 07, 2007

Welding Symbol Guide

A good collection of Welding information on the net is located at:

Fillet weld symbols

Groove weld symbols

Good Overall Welding Related information is located at

Industrial troubleshooting using Radioisotopes

TCR (India, Kuwait, Saudi Arabia) in association with its Associates have upped its skills to now undertake intelligent pigging as well as other services to help conduct detailed quality inspections and assessments of pipelines/ reactors/ vessels/ process columns in refineries, petrochemicals, chemical, oil and gas industrial vertical.


TCR now undertakes:

• Blockage detection in underground pipelines

• Leakage detection/location in pipelines

• Gamma scanning of various process columns

• Residence time distribution analysis


Blockage detection in underground cross-country pipelines

TCR can undertake Blockage detection of almost all the major cross country pipelines using radiotracer pigs. Sealed source used is 5-10 mCi of 137Cs or 60Co. Associates of TCR have worked on the Mumbai - Pune 160 Km long pipeline, Kandla - Bhatinda pipeline, Vaizag - Vijaiwada 350 Km long pipeline and many other noteworthy projects.


Leakage detection/location in pipelines

Radiotracers are extensively used for locating leakages from underground pipelines and in industrial systems. The technique is cost effective. in the past, TCR Associates have accurately determined and located leaks of the order of 1 litre/hour from 10" dia cross country pipelines.


The principle of the Leak detector pig method is as follows:

1.  Leaky section fitted with pig launcher & receiver, radiotracer inlet & outlet

2.  Marker sources are placed on pipe in the dug pits at regular intervals

3.  Pipeline filled completely with diluted radiotracer (short-lived : mostly 82Br as ammonium bromide)

4.  A Data logger records the location of leak with respect to marker sources and downloads the same to a computer

5.  Location of leak is exactly identified with respect to location of marker sources


Gamma Scanning of various Process Columns

Gamma Column Scanning Technique is the only technique to view inside the column. Using this technique TCR, in conjunction with a RLA study, TCR can determine the health of a process column and help plants generate maximum output.


Residence Time Distribution Analysis (RTD)

In a chemical reaction of known kinetics, the extent of conversion will depend upon the time of reaction or MRT. The resulting distribution of residence times (RTD) governs the overall reaction. Most widely method used for visualization of RTD is ‘stimulus response technique.’ Interpretation RTD curve leads to determine dynamic hold-up of fluid flowing in the system.


A computer generated RTD curve gives information such as:

• Type of flow (plug flow, well mixed flow)

• Flow anomalies like, channeling, bye-passing, recirculation, presence of dead zones, parallel flow, etc.


TCR's associates have custom developed an RTD software that helps and assists in all analysis efforts.


To get a quote for any of the above services, please contact





Thursday, September 06, 2007

Innovative Pre-Treatment Techniques To Prevent Corrosion Of Metallic Surfaces

There has long been a need for effective pre-treatment techniques to prevent corrosion of metallic surfaces. This important volume discusses key research on the development of pre-treatment techniques for a range of metals. Chapters review various coatings and preparation methods for aluminium and aluminium alloys such as silane films, sol-gel coatings and magnesium-rich primers. Further chapters discuss the pre-treatment methods for steel, copper and magnesium alloys. The book also assesses methods for monitoring the effectiveness of pre-treatments, covering dissolution-precipitation mechanisms and their electrochemical behaviour.   


Innovative pre-treatment techniques to prevent corrosion of metallic surfaces will be a valuable reference for all those concerned with corrosion problems and the use of pre-treatment techniques in the coatings industry.  


View the complete index of this report.

Wednesday, September 05, 2007

Dataquest mentions RoHS Services of TCR

Dataquest, a computer magazine in India, has mentioned about the RoHS compliance Testing services in India of TCR Engineering Services in an article titled Going Green. This article is written by Subbalakshmi BM (With inputs from Amrita Tejasvi in Delhi and Piyali Guha in Kolkata).

TCR Engineering Services provides RoHS testing in India to detect RoHS and WEEE non-compliance for restricted substances. TCR also conduct tests on Metals, Electronics, Soils, Mining, Minerals, Lead Inspection, Woods, Paints & Coatings, Oils & Liquids, Thin Films and Hazardous Waste Materials using X-Ray Fluorescence (XRF) spectrometer.

ASNT Fall Conference @ Las Vegas

Why attend The American Society for Nondestructive Testing's Fall Conference and Quality Testing Show in Las Vegas this November? Why, because no other NDT conference brings together, at a single event, the array of utilizing industries, method applications and technology developments. Attend the 2007 ASNT Conference that features more than 115 papers, covering a range of relevant NDT topics. Enhance your current NDT knowledge. Earn valuable CEU's by participating in short courses or the post conference seminar. See the latest NDT developments in equipment and meet with service providers.

Rohit Bafna, Director Global Sales, from TCR will be at this conference. He looks forward to meeting everyone at the show.

Are you in Bahrain? Do you neet Metallurgical or NDT Services?

Do note that all of TCRs Senior Management is going to be in Bahrain from Dec 2-5 and we will appreciate if we could meet your QA management at that time. Do note that our management team is doing a presentation of a paper at the Fourth Middle East Nondestructive Testing Conference and Exhibition (4MENDT 2007) which is being held at the Gulf International Convention Center, Kingdom of Bahrain from December 2 to 5, 2007. We are also having a booth at this exhibition and I request you to attend for the same.

There are a number of services we provide especially in the areas of metallurgy and we can be of great help to a company. Do also bookmark our website at as new services are always posted there.

Are you sourcing Metal parts from India?

There are a number of areas where TCR can provide assistance to any sourcing projects from India, especially when sourcing castings and forgings. We can undertake the following:

  • Factory Audit of Forging and Casting Vendors
  • Third party Inspection (including dimension verification, documenting NCR’s and shipping audits) and Status Reporting
  • Material Testing including mechanical and chemical tests, corrosion studies and NDT
  • Sourcing Assistance (on a best effort basis, wherever possible)
  • Project Management
  • Engineering consulting especially in the field of metallurgy

Independent, third party inspection and quality assurance services, including Factory Audits, OEM Development, Raw Material Inspection, Initial Production Check, In-Production Check, Random Inspection and Loading Supervision directly on-site at your vendor / supplier location in India.

Engineering Consulting to source materials and products from India. On-site Quality Analysis directly at your supplier or manufacturer's location in India with our Positive Material Identification (PMI), inspection and material testing team.

TCR's dedicated engineering and metallurgical consulting team in India is a perfect partner for solving manufacturing and product quality problems. Several senior consultants with many years´ experience are available to help and advise on corrosion or materials selection queries. The metallurgical consulting team also advise on welding engineering, heat treatment problems, verifying product integrity, measuring performance and determining end of life to enhance product performance and quality.

From initial product design, through final production, TCR in-depth engineering consulting services ensures that clients are producing the best possible product. The cost for engineering consulting service is billed on a per hour basis with a 4 hour minimum.

Talented NDT Level III Manpower - Now Available

As luck would have it, there have been a number of projects that ended at the same time and we now have 5 really talented NDT Level III personnel (some with additional API and AWS/CSWIP certifications) available to work as consultants on projects anywhere in the world. Our personnel are currently in India. The manpower rates from TCR are priced competitively and our qualified personnel are well regarded for their intellectual and documentation abilities. We can place these personnel at a short notice. Contact the sales team at TCR if interested.


Tuesday, September 04, 2007

Vacuum Box Test in India and Saudi Arabia

TCR Engineering Services (in India and the Middle-East) now undertakes vacuum box for testing welds on tank floors and floor to shell welds. This test method covers procedures for detecting or locating leaks, or both by bubble emission techniques.

The technique is applicable to any test specimen on which a pressure differential can be created across the area to be examined. An example of this technique is the application of leak-test solutions to pressurized gas-line joints. It is most useful on piping systems, pressure vessels, storage tanks. TCRs boxes can be fitted to the proper type of weld: butt weld, fillet weld, corner fillet weld.

TCRs vacuum boxes can be used to test as per API & ASME specification for in-service tanks and produces an operating vacuum of 20 inch Hg (10 psi).

Monday, September 03, 2007

Call for Papers: Fourth FICCI-Energy Technologies Forum 2008

Federation of Indian chambers of Commerce and Industry (FICCI) is organizing the 4th International Energy Conference & Exhibition, Energy Technologies Forum 2008 (ETF 2008) from from 10th to 11th January 2008 in Mumbai. The theme of the conference is “Energy Future: Efficiency & Conservation”.  ETF 2008 offers an excellent opportunity to Energy Sector, their associates and academia to deliberate and showcase their services and products.

The past three edition of ETF had been a grand success. In view of emerging business scenario and advances in technology in the energy Sector, ETF 2008 will bring out many value added opportunities to the participants. The technical & business topics of ETF 2008 will cover the whole gamut of Energy Sector i.e. Oil & Gas, Power & New and Renewable Energy.

The energy-council is inviting technical deliberations by contributing a paper in the area of your interest. The abstract may please be submitted positively by 30th September 2007 through email at

NDT Training - Course Material and Tests

NDT Resource Center has provided an excellent resource for all students that wish to learn more about Non Destructive Testing. The materials contain some interactive Flash and Java applets which help illustrate important concepts and can be used as NDT calculators. While the target audience in college students, NDT professionals may find the information interesting as useful as well.

Course and Tests are placed for each for the subjects given below:

Oil companies find shortage of engineers

USAtoday reports on an article titled, Oil companies scramble to find engineers.

Bustling oilfield activity and retiring baby boomers, among other factors, have petroleum outfits large and small trying to hire thousands of engineers, and experts say the trend is expected to extend into the next decade as worldwide energy demand grows.

"I've talked to quite a few of my peers, and we know we're in a good spot," Cornell University's Reasor said as she and Arsenault, of the Massachusetts Institute of Technology, took part in a week-long recruitment program sponsored by Royal Dutch Shell's U.S. arm. "It's nice to know we're needed."

Management consulting firm Oliver Wyman says roughly eight in 10 global oil and gas companies forecast a shortage of petroleum engineers through at least 2011. The American Petroleum Institute said U.S. energy companies will need at least another 5,000 engineers by decade's end.

Fossil fuels — despite efforts to find and market alternative fuels — will continue to be the world's primary energy source for the foreseeable future, making petroleum and other engineers vital for finding and extracting oil and natural gas from all around the world.

And demand is only going to grow.

The shortage of engineers has been caused in part by the upsurge in exploration and a wave of retirements from baby boomers who have spent 25 to 30 years on the job.

Articles on Failure Analysis

The Plant Maintenance Resource Center established in 1996 by Alexander Dunn, an experienced Maintenance professional and Maintenance Consultant, based in Australia provides an extensive list of Articles on Failure Analysis including articles from TCR Engineering Services. This site is filled with high quality content, and relevant to modern Maintenance Managers and Maintenance Professionals.

Sunday, September 02, 2007

Corcon 2007, a NACE India Event

TCR Engineering Services, India's leading ISO 17025 accredited independent materials testing laboratory and its associate company TCR Advanced Engineering Services will be exhibiting at the CORCON 2007 International Conference & Exhibition on Corrosion Control to be held on 26-28 September 2007 at Intercontinental Grand, Mumbai, India.

The event is being organized by NACE International India Section. NACE International India Section (NIIS) established in 1992 promotes corrosion awareness to achieve aims and objectives of NACE International USA. Also part of this event is the NIIS Corrosion Awareness Award 2007.

A number of Corrosion related tests are undertaken by TCR to determine weight loss corrosion, inter-granular attack, pitting corrosion, corrosion fatigue, stress corrosion cracking, sulfide stress cracking, and hydrogen-induced cracking. TCR’s Sour Service Corrosion Testing department undertakes Small Scale Tests and Full Ring Testing for SSCC (NACE TM 0177, EFC 16 and 17) and HIC (NACE TM 0284). The range of instruments available to perform these tests in unrivalled in India. Highly experienced and qualified engineers within the group routinely undertake corrosion studies to include all observations as per NACE MR 0175.

Meet TCR representatives at Corcon 2007.

Radiation Safety Offer Needed in Yemen

The candidate should have a University graduate in science or related discipline and experience in Radiation safety. Experience of about seven years. They will sit for an exam at Yemen’s Atomic Energy Council. We need three of such personnel.

Duration of contract: one year.

Allowance of one month leave every six months.

Food, accommodation, transport, including round trip tickets from India to Sanaa, Yemen will be provided by us..

Working hours 11 hrs per day, seven days a week.


Again, we want to notify you that Yemen’s National Atomic Energy has upgraded the qualification of the RPO should have a university degree and up to date Level II certificates and enough experience.

To apply contact TCR Engineering Services.

Automated UT using ToFD

Time of Flight Diffraction (TOFD) is an advanced and automated weld examination technique that assists in Fitness For Purpose (FFP) inspections. Using TOFD, the expert NDT team members at TCR-KIL in Kuwait and TCR Arabia in Saudi Arabia perform amplitude-independent accurate flaw sizing on a wide coverage area.

TOFD is a fast and efficient way to scan a lot of weld area in a very short time period. Dead zones near the front and back surface can be enhanced using combined TOFD and conventional pulse echo techniques.

Saturday, September 01, 2007

Now Hiring - Heat Treatment Technicians

Sr. PWHT Site In-Charge 

Location: Initially in India and then moved to Saudi Arabia

Status: Staff

Interview Location: Navi Mumbai, India

Over 8 years of experience on refinery/ Petrochem/oil and gas plants project sites working on pre heating, post weld heat treatment of different kinds of components. Work will involve supervising  a crew of technicians and conducting interpretation of ASME, API and ASTM codes and specifications. Should be able to create working procedures based on code interpretation and ensure that all team members work in adherence to the quality standards of TCR.

Must be well versed in Oil Fired Furnaces, Gas Fired Furnaces, Transformer and ceramic mats heating and Automatic temperature control units.

Should have experience in making various types of small size furnace with ceramic heating mats for heat treatment of small components and welded spools. Must be well trained in repairing of electromagnetic yokes, heat treatment trans-formers, making of various kinds of heaters and furnaces.

Must be able to sit for prolonged periods of time and ensure that the client's QA standards are never compromised. Capable of cross-training department personnel to perform job functions in various inspection areas.

Ability to perform job functions with little or no supervision. The candidate should be highly motivated, self driven and an effective communicator, especially in the English language. Good computer literacy is essential for this position. Should be able to work in any type of rough climates environments. Additional experience in UT, DP, MP, WFMPT is a plus.

Click Here to apply.