Understanding Heat Exchanger Reading 03- Part 2 of 2 The ARAMCO Std.

Document Responsibility: Heat Transfer Equipment Standards Committee
32-SAMSS-007
Draft Date: 1 December 2013
Next Planned Update: 1 December 2018
Manufacture of Shell and Tube Heat Exchangers
Material Fiber Elongation Strain ε f (%) Heat Treatment Requirement
Carbon Steels P-1
Low Alloy Steels P-3, P-4,
P-5, P-9A & P9B
High Alloy Materials
Non-ferrous Materials
Less than or equal to 5
Greater than 5 and
equal to or less than 10
Greater than 10
Less than or equal to 3
Greater than 3 and
equal to or less than 10
Greater than 10
Table 6.2 of ASME Section VIII,
Division 2
Table 6.3 of ASME Section VIII,
Division 2
None
(Exception: PWHT per the applicable Code
shall be performed for cold spun heads)
PWHT per the applicable Code
Normalizing, Normalizing and tempering or
quenching and tempering, as required to
maintain original material properties.
None
(Exception: PWHT per the applicable Code
shall be performed for cold spun heads)
PWHT per the applicable Code
Normalizing, normalizing and tempering or
quenching and tempering, as required to
maintain original material properties.
Table 6.2 of ASME Section VIII, Division 2
Table 6.3 of ASME Section VIII, Division 2
b) Calculation of forming fiber elongation strain εf (%) shall be according to the
following:
Type of Part Being Formed Fiber Elongation Strain ε f (%)
For double curvature heads that are formed from onepiece
or welded multi-piece blanks by any process that
includes dishing or cold spinning (e.g., dished heads or
cold spun heads)
For heads that are assembled from formed segments
(e.g., spherical dished shell plates or dished segments
of ellipsoidal or torispherical heads)
ε f = 100 ln [D b /(D f -2t)] [1]
ε f = 100 t / R fd [2]
Cylinders and cones formed from plate ε f = (50 t / R fc ) [1-(R fc / R o )] [3]
Where:
ln
D b
D f
is the natural logarithm
is the diameter of unformed blank plate or diameter of intermediate product
is the outside diameter of the finished product
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