TEMA is said to be valid for fabrication and not for design of Heat Exchangers
you need both....
TEMA is a STANDARD that provides guidance for the thermal design and various common design details of Shell & Tube heat exchangers.
TEMA recommends design features such as tube spacing, tube supported span, tubesheet design ... etc, including flow-induced vibration analysis of tubing
ASME Section VIII, Div. 1 is an internationally recognized CODE that is commonly used for the strength design of heat exchangers. ASME VIII is used to calculate the minimum wall thickness of the shell and channel heads etc.
Whereas, TEMA is concerned with internals, such as pass partion plates, baffles, and impingement shields, these items are outside of the ASME scope.
You must understand the differences between a STANDARD and a CODE..
ASME PV CODE is the Construction code for S&T Heat Exchangers. It addresses minimum thickness requirements for shell, channel / bonnet and tubesheet. The design features like tube spacing, tube supported span, thickness of pass partition plate, trnsverse baffle and support clearances, tube hole size in tubesheets etc are not the scope of ASME PV CODE. These features plus other necessary informations regarding S&T Heat Exchanger design are covered in TEMA.
BalasHapusFor Tubesheet Thickness, Greater of the thicknesses calculated by ASME PV CODE or TEMA was used earlier. But now (TEMA 2009) TEMA tube sheet calculations are not mandatory and only ASME PV CODE (SEC VIII DIV I PART UHX) is used for tube sheet thickness calculation.
ASME PV CODE requiremets for tube sheet thickness calculations are more stringent than those described in TEMA.