In India, Hi-Hi Screw Plug/Breech Lock Heat Exchangers are under-designed and sold under the garb of proprietary equipment, enabling manufacturers to get away with substandard equipment. TEMA India Founder – MD Haresh Sippy questioned the concept of proprietary equipment. “What is proprietary technology? Who is the proprietor? TEMA India challenges this claim,” he said.
In the year 1999, the prototype of the modified design developed by TEMA India was built. Several tests were conducted to verify and successfully adopt this added steel on the threaded area of the closure.
Describing the occurrence of bell-mouthing in the threaded area of the channel barrel in equipment manufactured by ‘proprietary’ technology as a potential hazard, he added, “Consequently, the channel barrel designed as per ASME Section VIII Division 2 leads to jamming of the threads, making it impossible to open for service.”
Haresh Sippy emphasised that the answer to the problem wasn’t welding higher thickness to the lower one, as is followed by some companies in India. “This is dangerous in this type of geometry, as clearly stated by the specs defined by Chevron, the pioneers of this technology and its licensors. It is a potential hydrogen bomb, ready to explode.”
This problem and the solution of adding steel on the threaded area can be seen in the diagrams below.
BS VI/EURO VI compliance is the need of the hour
The Founder-MD of TEMA India was recently speaking on Screw Plug/Breech Lock Exchangers at two important industry meets; the Refinery Technology Meet in Vizag in April 2017 and the Global Refining and Petrochemicals Congress 2017 in Mumbai on May 26. He made this point when elaborating the urgency of upgrading to equipment necessary to meet the stringent standards of BS VI/EURO VI.
For the first time, much interest has been generated in the mechanical design of Shell & Tube Heat Exchangers. This is unusual, given that these fora were devoted to process-oriented research for increasing efficiencies. This, he said, “was only due to the nuisance value these exchangers have. Intermixing of fluids on account of poor design inhibits refineries from being able to reduce the sulphur content in diesel and refine clean fuels as per the norms of BS VI in India and EURO VI, the world over.”
Intermixing of fluids is the key reason for failure of Heat Exchangers
Failure on this front has been reported at IOCL refineries across the country. It is a result of intermixing of two fluids in a Hi-Hi Screw Plugs construction, one with high sulphur content mixes with the other with negligible sulphur. This happens due to the faulty design of this Shell to Tube-Sheet joint.
“Heat Exchangers used by the Oil & Gas industry have the highest nuisance value. They require, what we term, an extremely rigorous level of service because it is hazardous, dirty, corrosive, high-pressure and high-temperature. Going the conventional route will impact safety, and being impossible to maintain, such Heat Exchangers will reduce efficiency. It will be like going back to the bullock-cart age or from the frying pan to the fire,” he added.
The answer to all problems: correctly designed Shell to Tube-Sheet joint
The Shell to Tube-Sheet joint in the Hi-Hi construction, if designed correctly, is completely leak-proof and the finest in the world. Over 150 of our Heat Exchangers based on this construction working at full efficiency the world over, is testimony to the fact that ours are the finest designed, engineered and fabricated Hi-Hi Screw Plug Heat Exchangers anywhere in the world.
Establishing industry standards together
“We have to establish quality and design standards. This will solve all our problems and we will be in a position to check the design quality of the product at every stage of manufacturing. We have already taken a big lead in defining these standards. What’s more, ASME, the world authority on this matter has taken the copyrights from us on this very issue. Two papers have been accepted and presented at ASME 2016 & ASME 2017. Both these papers pertain to Hi- Hi Screw Plugs; the ones that are failing in service all over the world.”
Haresh Sippy exhorted the audience to join hands to change the situation. “India is full of talented engineers and technologists. Let’s all come together for a global cause such as clean fuels and set an example for the world to follow,” he signed off.
To know more about how TEMA India’s Screw Plug/Breech Lock Heat Exchangers can make BS VI compliant, visit www.temaindia.com
To read the papers submitted to ASME, visit
Title: An Improved Design of Threaded Closures for Screw Plug Heat Exchangers