My name is Krishna Sampath, and I joined Chart Industries at Ball Ground, GA in August 2008.

Chart Industries manufactures a variety of cryogenic tanks for storage and distribution of liquified Argon, Nitrogen, Oxygen, Hydrogen and Helium besides Carbon-dioxide. In 2009, at Ball Ground, GA location we started pressure strengthening of cryogenic inner tanks that are made from AISI 304 stainless steel. The long seams and circular seams of these Inner tanks were welded using the Metal Inert Gas (MIG) welding process. Later, ASME Section VIII introduced Mandatory Appendix 44 for the long seam welding of the cryogenic Inner tanks. The Mandatory Appendix 44 imposed severe restrictions on weld reinforcement at the weld face and root. Such restrictions were difficult to implement with MIG welding process and required extensive grinding. We were actively looking for an alternate welding process that could meet the severe restrictions on weld reinforcement at the weld face and root while also achieving both high quality (zero defects) and greater productivity.

At that time, we came to know Mr. Perry Cooper of Air Liquide Welding and he introduced us to Plasma + TIG welding process and equipment for long seam welding. Initially, he took us to a manufacturing facility near Toronto, Canada where the Plasma + TIG welding equipment was being used to build a variety of pressure vessels for chemical industries. The Plasma process is used to ensure full penetration while the follow-on TIG welding ensured smooth weld face consistent with the Mandatory Appendix 44 requirements. But, as a metallurgist and welding engineer, I had concerns that the plasma weld could possibly create a plane of weakness along the weld centerline, and that could perhaps open-up during pressure strengthening. I expressed my concerns to Perry Cooper, and he offered to weld a tank at the Air Liquide Welding facility in France, free of cost. We received the welded shell back in Ball Ground, GA, added the end caps and subjected the Inner tank to pressure strengthening. Later, we did a variety of non-destructive and destructive testing on the pressure-strengthened Inner tank and established that the Plasma+TIG welding process could meet all our needs.

Subsequently we ordered and received the Plasma + TIG seam welder and trained our manufacturing staff. Perry Cooper helped us with detailed training materials and hands-on training with equipment set-up and controls.  In a short time, Perry Cooper enabled us to achieve all our manufacturing metrics. Subsequently, we installed similar but larger equipment in our New Prague facility in MN, and later on at our manufacturing facilities in China and Germany. The Plasma + TIG seam welder in China is also used for building stainless steel cryogenic tanks for trailers while the German facility uses for building aluminum cryogenic tanks for trailers.

All these additions to our asset list ensured excellent quality and high welding productivity. Perry Cooper helped us at every step of the way from installation to commissioning, and staff training.

Perry Cooper demonstrated to us his full commitment in meeting and/or exceeding our manufacturing needs with the right equipment and controls. His understanding of customer needs is exceptional and he ensured that he could fulfill all our expectations with the right kind of welding equipment and controls besides offering necessary training materials.

Respectfully,

Krishna Sampath