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Quotes - Engineering - SalesU-Tube Heat Exchangers For
TEMA Classes R, C and B
U-Tube Duty
TEMA publishes mechanical standards for shell and tube exchangers, and divides construction into three classes reflecting service severity. The class affects thicknesses, allowances, clearances and tolerances rather than the fundamental arrangement.
Class R. Intended for the severe requirements of petroleum and related processing applications. The heaviest construction, largest corrosion allowances and tightest tolerances. Specified widely in refining and petrochemical service.
Class C. General commercial applications. The lightest of the three and entirely appropriate for utility duty, HVAC, and general industrial service where the severity does not justify more.
Request a QuoteTEMA Classes R, C and B Applications
Do Not Specify R by Default
Class R appears in a lot of specifications that were written for refinery service and then reused. On a plant utility heater it adds material, cost and sometimes lead time, and returns nothing the duty will ever use.
Conversely, specifying Class C on genuinely severe service is a false economy, because the smaller allowances and lighter construction shorten the life you get. Match the class to the severity and the decision is straightforward.
Selection Data We Need
Flow rate and identity of both fluids, inlet and required outlet temperatures, operating and design pressures, allowable pressure drop on each side, and any code, alloy or hygienic requirement. Fouling history, turndown range and cleaning method matter as much as the design point.
