S Sankaran : A consultant to Welding Consumables & Fabrication industries

“They have no awareness about more efficient welding inverters which are the current trend.”

 S Sankaran : A consultant to Welding Consumables
& Fabrication industries,
A Fellow of the Indian Welding Society,
A Founder Chairman of IWS-Western Zone

You are highly recognized for your extensive contributions towards welding technology and engineering.  Please introduce a more about you?

Basically, I am a Mechanical Engineer.  I have been in the Welding Engineering field for about  50 years. I have worked in leading Public Sector and Private Sector firms including Welding Research Institute.  My work experience is related to Boilers, Pressure vessels, Heat Exchangers, Earth Moving equipment, Nuclear, Aerospace and Defense Projects.  After retirement from active service, I am sharing my knowledge and experience by doing consultancy and welding educational programs.

What challenges did you come across when you planned to start your career in welding? Infact, what made you choose welding as a profession, which I believe was not a trend during your time?

As part of my undergraduate, I had summer internship in BHEL-Tiruchy and BEML-Bangalore. I observed that a variety of welding processes were extensively used in fabrication, and welding was the key manufacturing process. But, very little about welding was taught in the undergraduate program. I developed special interest in welding.  I joined IIT-Madras for post-graduation in Metal Joining. Simultaneously, I was also looking for a career in welding engineering at BHEL, L&T or BHPV.  In the first interview which I attended, I was selected as graduate engineer trainee in BHEL and posted to welding technology department at BHEL Tiruchirapalli.

You started your career in Welding Technology Department of Bharat Heavy Electricals Ltd. Tiruchirapalli. Can you share some of the interesting anecdotes during this period?

After the orientation programs, I was posted as a Trainee in the Welding Technology Department which was attached to the Boiler Production Shops. My first boss was Shri. B Pattabhiraman. He was my mentor and he groomed me with good industrial work culture, and exposed me to the state-of-the-art welding processes and technology.

At that time, BHEL was switching over from Czechoslovakian Technology for 60 & 110 MW capacity boilers to American Technology for high pressure 200 & 500 MW capacity boilers.  Many latest welding processes like Tandem-arc SAW, Pulsed-arc GMAW, Orbital GTAW, Induction Pressure welding, Special Purpose Machines for Panel Processing with Multi-arc SAW were being introduced. Shri. Pattabhiraman would pick me from my hostel after dinner and we would go to the workshop and work on these machines to do welding trials, optimizing the welding parameters etc. till one O’clock in the night. That gave me a very good exposure and practical work experience.

It feels great to know that right from student days you have been an active member of The Indian Institute of Welding. And have been a leading member of various other welding institutes? Please elaborate.

It was during my internship in BHEL, Shri. S K Mazumdar inducted me a student member of Indian Institute of Welding. I took interest in the activities of the professional body and became an office bearer of the Tiruchirapalli Branch and later the Mumbai branch of IIW. I was a member of the National Council of IIW. When the Indian Welding Society was formed, I became the founder Chairman of the IWS, Western Zone. In 2005, I organized the first Asean Welding Federation Meet and IWS5K conference at Lonavla.  I was the President of IWS during 2009-11. The International Welding Conference IWS10K and Welding Exhibition was held in 2010 at Mumbai.

I was made a Fellow of IWS and honoured with ‘Legend of IWS’ award in 2012.

Receiving “Legend of IWS” Award

Can you quickly take us through your qualification background?

I did my Bachelors degree in Mechanical Engineering from Regional Engineering Collage,  Tiruchirapalli  (Now, National Institute of Technology).  I joined IIT Madras for Post-Graduation in Metal Joining. When I had completed one semester, I was selected as Graduate Engineer Trainee at BHEL Tiruchirapalli.  I discontinued the Post-Graduation and joined BHEL.

You received training in USA on advanced welding methods for manufacture of high pressure boilers. Can you please highlight on some of your learning, which can be a great info especially to our boilers industry readers?

I was trained in welding technology related to high pressure boilers of 200 & 500 MW capacities at the Combustion Engineering USA. Two weeks training was at the Materials & Metallurgical Research Laboratory, where welding Research & Developments related to new materials, welding processes were going on. Four weeks training was in the boiler shops on welding processes and equipments like Tandem arc Narrow groove SAW, Pulsed arc MIG welding, Orbital TIG welding, Induction pressure welding etc. I was exposed to the application of welding in manufacture of several boiler components like Steam Drum, Headers, Economiser, Super heater, Reheater, Main Steam pipes etc. My training was scheduled in Jan-Feb of 1978. Unfortunately, there was unprecedented snowfall during that time and a few planned visits to Boiler Erection sites and a few Welding Consumable & Equipment manufacturers had to be cancelled.

You have played an active role in implementing latest welding processes and indigenous development of welding consumables. Can you discuss on some of your developments?

BHEL had technical tie up with Czechoslovakia for 60 and 110 MW capacity boilers. All welding electrodes for high temperature service were initially procured from Czechoslovakia. But the supplies were very erratic. So, equivalent welding electrodes and wires were sourced from European countries & Japan. They were tested and approved in BHEL involving the Tamilnadu Boiler inspectorate.  Indigenous developments of these welding consumables were also taken up in parallel. The imported electrode samples were given to Advani Oerlikon. D&H Secheron and Philips India and the equivalent brands were developed by them.  Extensive trials and testing was done. The Tamil Nadu Boiler Inspectorate under Mr. S. L. Theobald had a very positive and constructive role in this development, Testing & Approval. The indigenous brands were very user friendly and were readily accepted for use by our welders.

There was one interesting episode. As a part of the know-how transfer the American collaborator had deputed a welder to demonstrate the welding techniques involved to our welders. He was demonstrating how to do the header to stubs welding. He held the electrode holder on his right hand and supported his arm on his left hand for steadiness. He welded one half of the stub by his hand movement. He stopped the welding and repositioned himself on the other side of the header to complete the other half. One of our welders took the holder from him. With his left hand totally free, he made the full circular weld by his hand and wrist movement without any interruption. The American was amazed at the skill of our welders and the dexterity of the wrist movement. He had also brought some American brand electrodes with him. When our Indian equivalent brand electrodes were given to him for welding demonstration, he found them more user-friendly and certified that they are better than the American brands in performance characteristics.

It feels great to understand that you established the School of Welding. Please elaborate.

When the Welding Research Institute was established under BHEL Tiruchirapalli with the assistance of UNDP, the first activity to start was Education & Training programs in Welding and allied subjects. The School of Welding was established to provide both practical and theoretical exposure to Welders, Welding Supervisors, Welding Inspectors, and Engineers. Both long term and short duration programs to suit practicing persons at various levels were designed and conducted. The welders were also qualified under IBR and other codes. These programs became very popular among public & private sector firms all over India.

Can you describe us on Thermal Power Station at Tripoli in Libya? What was your role in the project? Any incident you wish to share during your tenure? What challenges you faced while on this project and how you cope up?

BHEL received a turn-key order for manufacture, erection, commissioning and operation of two 120MW thermal power plants at Tripoli, Libya. I was deputed at the start of the construction work at Tripoli site. I was in charge of Welding, Heat Treatment and NDT.

You were a Head of the Welding Engineering at the Bharat Earth Movers Ltd? What type of projects have you worked upon? Any interesting project you would want to discuss about, especially considering the welding aspect?

BEML was extensively using CO₂ welding.  But the welders had no formal training in CO₂ welding. I organized training programs in both theory & practice for about 300 CO₂ welders and qualified them as per structural welding code. With the help of TWI-UK, design engineers were trained in design improvements to enhance fatigue life.

Several cases of failures at construction sites were analyzed and quality improvements were implemented in fabrication. I was also associated in preparation of Quality Manual, Quality Standards & Work Instructions to get the ISO 9001 certification.

At Larsen & Toubro Ltd you worked as a Head of Welding Engineering & Metallurgy Department of the Heavy Engineering Division, at Powai, Mumbai. We are keen to understand the projects you worked upon in L&T. Any interesting project you would want to discuss about?

At L&T we were fabricating pressure vessels and heat exchangers for Refinery, Petro chemical, fertilizer plants for both domestic & overseas projects. We were also the premier manufacturer of equipment for Aerospace, Nuclear and Defense projects. Each job was unique and technically challenging in terms of materials involved, code of construction, and Specifications of process consultant. With excellent teamwork involving Welding Engineering, Production Engineering and Fabrication shops, many automation projects involving new tube-to-tube sheet welding configurations were implemented. Several first-time in India kind of jobs were executed. Few most significant developments were;

1) Internal bore welding technology meeting stringent micro-focal X-ray (30X magnification) and weld profile requirement for 500MW Fast Breeder Reactor Steam generator Tube-to-Tube sheet welds of modified 9CrMo material.

Internal bore welding joint detail. Mock up welding

2) Fully automatic Narrow-groove GTAW with arc oscillation and hot-wire addition for 1800mm diameter 90 mm thick joints with Modified 9CrMo material.

Automatic Narrow Groove GTAW with Arc Oscillation Hot-Wire addition.
1800mm Diameter, 90mm thick, Modified 9CrMo

3) Approval for manufacture of Urea plant equipment from Process Licensor like Snamprogetti and Stamicarbon.  These involved;

1. a) Automatic Tube-to-Tube Sheet welding of Bi-metallic Zirconium lined tubes with 17 mm tube projection.
2. b) Weld overlay of 3mm height on 6mm thick urea grade 25Cr22Ni2Mo stainless steels. (Picture 6)
3. c) Electro Slag Strip Cladding of Stamicarbon’s proprietary Super-Duplex Stainless Steel (Safurex).
4. d) Automatic Tube-to-Tube Sheet welding meeting very stringent tube wall fusion requirements.

4) Development and implementation of single layer ESSC meeting Hydrogen disbanding test for various grades of Stainless Steels, Nickel and Copper based alloys resulting in substantial cost and cycle time saving.

SS overlay on 6mm thick urea grade SS liner
T-TS welding Zirconium lined tubes with 17mm projection.

5) Developing and implementing Pulsed arc GMAW for crevice free Tube-to-Tube sheet joint design in thin wall tube sheet for waste heat boilers. Welding cycle time was reduced from 35days for GTAW to 19 days for GMAW and it helped to meet stringent delivery requirement by overseas customer.

Single Layer ESSC weld overlay of reactor vessel shell course

6) Implementing penetration enhancing A-TIG welding to achieve consistent all around penetration of 3.5mm in single pass autogenous GTAW for Effluent cooler where customer required Tube-to Tube sheet weld  to be located 25mm inside from the back side of tube sheet.