1. Heat Exchangers Design and Construction
Chemicoz

2. Introduction:
Shell and tube heat exchangers are one of the most common equipment found in all plants
How it works?

3. What are they used for? Heat Exchanger Cooler Heater Condenser
Classification according to service .
Heat Exchanger
Both sides single phase and process stream
Cooler
One stream process fluid and the other cooling water or air
Heater
One stream process fluid and heating utility as steam
Condenser
One stream condensing vapor and the other cooling water or air
Reboiler
One stream bottom stream from a distillation column and the other a hot utility
or process stream

4. Design codes: Code Standard Specifications
Is recommended method of doing something
ASME BPV – TEMA
Standard
is the degree of excellence required
API 660-ASME B16.5–ASME B36.10M–ASME B36.19-ASME B16.9–ASME B16.11
Specifications
Is a detailed description of construction, materials,… etc
Contractor or Owner specifications

5. Main Components 1- Channel Cover 8- Shell 2- Channel 9- Baffles
3- Channel Flange
10- Floating Head backing Device
4- Pass Partition
11- Floating Tubesheet
5- Stationary Tubesheet
12- Floating Head
6- Shell Flange
13- Floating Head Flange
7- Tube
14 –Shell Cover

6. TEMA Heat Exchanger

7. TEMA Heat Exchanger
Front Head Type
A - Type
B - Type
C - Type

8. TEMA Heat Exchanger
Shell Type
E - Type
F - Type
J - Type
K - Type

9. Pull-Through Floating Head
TEMA Heat Exchanger
Rear End Head Types
M - Type
S - Type
T - Type
Fixed Tubesheet
Floating Head
Pull-Through Floating Head

10. Classification: U-Tube Heat Exchanger Fixed Tubesheet Heat Exchanger
Floating Tubesheet Heat exchanger

11. Example
AES

12. Example
AKT

13. Heat Exchangers Mechanical Design
Terminology
Design data
Material selection
Codes overview
Sample calculations
Hydrostatic test
Sample drawing

14. Terminology
ASME
TEMA
API
MAWP
MDMT
PWHT
NPS – DN – NB – NPT
Sch - BWG

15. Design Data Heat Exchanger Data Sheet : TEMA type Design pressure
Design temperature
Dimensions / passes
Tubes ( dimensions, pattern)
Nozzles & Connections
Baffles (No. & Type)

16. Material Selection Cost & Strength Corrosion Resistance Fabricability
Availability

17. Strength A – Yield Strength C – Rupture point B – Tensile Strength B A

18. Strength Creep Strength
a slow plastic strain increased by time and temperature (time and temperature dependant) for stressed materials
Fatigue Strength
The term “fatigue” refers to the situation where a specimen breaks under a load that it has previously withstood for a length of time
Toughness
The materials capacity to absorb energy, which, is dependant upon strength as well as ductility

19. ASME code Overview ASME BPV code Sec.I Power Boilers Sec.II Materials
Sec.III Nuclear Fuel Containers
ASME
BPV
code
Sec.IV Heating Boilers
Sec. V Non Destructive Examination
Sec. VI Operation of heating boilers
Sec. VII Operation of power boilers
Sec. VIII Pressure vessels
Sec. IX Welding and Brazing
Sec. X Fiber-Reinforced plastic PV
Sec. XI Inspection of nuclear power plant
Sec. XII Transport tanks

20. ASME code overview Sec. II: Materials
Part A : Ferrous material specifications
Part B : Non-Ferrous material specifications
Part C : Specifications of welding rods, electrodes and filler metals
Part D : Properties
Sec. VIII: Rules of construction of pressure vessels
Division 1 : 3 Subsections + mandatory Annex + non mandatory Annex
Division 2: Alternative rules
Division 3 : Alternative rules of high pressure

21. ASME code overview

22. TEMA code overview TEMA classes: TEMA subsections
Class R: Generally severe requirements for petroleum
and related processing applications
Class C: Generally moderate requirements of commercial
and general processing applications
Class B: Chemical Process service
TEMA subsections
10 subsection

23. Sample Calculations PR . SE – 0.6 P + CA t = + UT
Shell thickness calculations under Internal Pressure: PR
SE – 0.6 P
+ CA
t =
+ UT
t : Min. Required Shell Thickness
P : Design Pressure of Shell Side
S: Max. Allowable Stress of Shell Material
R: Shell Inside Radius (corroded conditions)
E : Joint Efficiency
CA: Corrosion Allowance
UT: Under Tolerance (if applicable)

24. Sample Calculations PR . SE – 0.6 P + CA t = + UT
Channel thickness calculations under Internal Pressure: PR
SE – 0.6 P
+ CA
t =
+ UT
t : Min. Required Channel Thickness
P : Design Pressure of Tube Side
S: Max. Allowable Stress of Channel Material
R: Channel Inside Radius (corroded conditions)
E : Joint Efficiency
CA: Corrosion Allowance
UT: Under Tolerance (if applicable)

25. Sample Calculations
Body Flanges:

26. Sample Calculations Body Flanges: Trial and error calculations
Gasket seating conditions
Operating conditions
No. of bolts and size
Bolt circle diameter
Inside and outside diameters
Check min. and max. bolt spacing
Detailed analysis of the flange
Forces calculations
Moment calculations
Stresses calculations

27. Sample Calculations Pairs of flanges
Precautions in body flanges design and installations:
Pairs of flanges
Bolt holes shall straddle center line
Corrosion Allowance
Cladding
Bolts shall be multiple of 4
Bolting shall be allowed to be removed from either side
Calculated thickness not include the RF

28. Sample Calculations Nozzles and standard flanges:
Flange Rating (ASME B16.5)
Area replacement calculations
Nozzle neck thickness calculations
Impingement protection
Sample

29. Sample Calculations Tubesheet:
Tubesheet is the principal barrier between shell side and tube side
Made from around flat piece of metal with holes drilled for the tubes
Tubes shall be uniformly distributed
Tubesheet thickness shall be designed for both sides
Tubesheet shall be designed for bending stresses and shear stresses
Corrosion allowance

30. For Triangular pattern
Sample Calculations
Tubesheet:
Tubesheet thickness for bending
T: Effective tubesheet thickness
S: Allowable stress
P: Design pressure corrected for vacuum if applicable at the other side
η: Ligament efficiency
For Square pattern
For Triangular pattern
G: Gasket effective diameter
F: Factor

31. Sample Calculations Tubesheet: Tubesheet thickness for Shear:
T: Effective tubesheet thickness
DL: Effective diameter of the tube center parameter DL=4A/C
C: Perimeter of the tube layout
A: Total area enclosed by the Perimeter C
P: Design pressure
S: Allowable stress
do: Outside tube diameter

32. Tube-to-Tubesheet joint
Expanded
Strength welded
Seal welded

33. Hydrostatic Test Test pressure : 1.3 X MAWP Test Procedure
Gasket change

34. Sample drawing Construction drawing is the design output

35. Thank You
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