Module 2 : Mechanical Design of Heat Exchanger

Lecture 1 : Mechanical Design Standards

 

 1. Mechanical design standards Of shell and tube heat exchangers

Mechanical design of heat exchangers includes design of various pressure and non-pressure parts. The structural rigidity and satisfactory service of heat exchangers depends on the appropriate mechanical design. Mechanical design is generally performed according to the design standards and codes. Some mechanical design standards used in heat exchanger design are: TEMA (United States), IS:4503-1967 (India); BS: 3274 (United Kingdom) and BS: 2041 4 (United Kingdom). The design structure of IS: 4503-1967 is provided in Table 2.1 [1] .

Most countries of the world follow the TEMA (Tubular Exchanger Manufacturers Association) standards for the mechanical design of unfired shell and tube heat exchangers . The TEMA standards are applicable for the maximum shell ID and wall thickness of 60 and 2 inch, a maximum design pressure of 3000 psi and a maximum nominal diameter (inch) × design pressure (psi) of 60000 lb/in, respectively [2].

Three basic classes of TEMA standards are: ‘ C ', ‘ B ' and ‘ R '.

 

Seven types of shells are standardized by the TEMA. The TEMA standards also specify the types of front-end, shell, and rear-end of shell and tube exchangers as shown in Figure 2.1 . For example, a fixed tube-sheet type BEM exchanger is illustrated in Figure1. 2 of module #1 .

Table 2.1. Structure of IS: 4503-1967 [1] .

Part 1

Scope

Part 13

Baffles and support plates

Part 2

Types and nomenclature

Part 14

Floating heads

Part 3

Terminology

Part 15

Channels and channel covers

Part 4

Classification and permitted pressures

Part 16

Nozzles and branch pipes

Part 5

Material of constructions

Part 17

Gaskets and gland packings

Part 6

Design stress

Part 18

Flanges

Part 7

General design

Part 19

Supports

Part 8

Corrosion and corrosion allowance

Part 20

Inspection

Part 9

Shells

Part 21

Testing

Part 10

Tubes

Part 22

Marking

Part 11

Tube sheet

Part 23

Preparation for dispatch

Part 12

Shell covers

Part 24

Certificates of compliance