High Pressure Shell and Tube Heat Exchangers
TEI-Struthers Wells Divison has supplied several thousand heat exchangers for essentially every type of application and in virtually every commercially available alloy. Heat exchangers have been designed for design pressures up to 7,900 psig, design temperatures up to 1600 F, and in sizes up to the maximum shipping limitations.
As one of the original founders of Tubular Exchanger Manufacturers Association (TEMA), and a charter member of Heat Exchange Institute (HEI), TEI-Struthers Wells Division has contributed in developing numerous standard mechanical, thermal, fluid, and vibration algorithms and calculation methods that have been the basis for many current modern computer programs used by many industry leaders.
TEi-Struthers Wells Division is a major supplier of Breech Lock heat exchangers, either directly or through its licensees to Chemical, Petrochemical, and Petroleum processes.
The tube sheet for the Breech Lock heat exchanger is designed for a differential pressure. The internal bolts are used to apply the seating load to the gasket at the tube sheet shell interface. The pressure end load is absorbed by the threaded closure and the outer row of external bolts applies the seating load to the channel gasket. The inner row of external bolts is used to increase the seating load between the tube sheet and shell gasket in the event of relaxation of the inner bolts.
The diaphragm closure is used in the Chemical and Petrochemical processes. The advantage is that the gasket seating load is zero (0) thereby reducing the size of the closure bolts. Because the diaphragm plate is seal welded to the channel, any potential leak paths of the channel fluid are eliminated.
The self-energized gasket closure may be utilized whenever the design pressure is equal to or greater than 3,000 psi or the diameter of the closure is greater than 90 inches. The gasket is flexible so that the internal pressure acting against it seals the closure. For this type of gasket, the bolts are designed for the end load. There is no gasket seating load.
Multi-wall Shell Construction
To overcome thick shell rolling limitations in the late 1950s, TEi-Struthers Wells Division developed a proprietary laminated shell called Multi-wall construction. Multi-wall vessels are utilized for Ammonia Converters and Urea Reactors. Due to the process fluids, the inner layer of the vessel is alloy material, such as Stainless Steel, Titanium, or Zirconium. The Multi-wall vessel solves many material and fabrication problems and presents a competitive design when compared to mono-wall vessels.