API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

RISK-BASED INSPECTION METHODOLOGY, PART 5—SPECIAL EQUIPMENT 5-41
Life Extension Method
Table 5.2—Effects of Bundle Life Extension Methods
Life Extension Factor (LEF) c
Plug Tubes 0.10
180° Bundle Rotation 0.50
Partial Re-tube 0.50
Total Re-tube 0.90
Install Spare Bundle b 0.50
Install Tube Ferrules a 0.75
a
This LEF is only valid when the tube ferrules are installed for protection against localized, tube-end damage due to
erosion, corrosion or impingement.
b
The spare bundle condition is known to be good through prior inspection. If the condition of the spare bundle is
known to be excellent, a higher LEF can be used.
c
LEFs provided in this table are suggestions. It is the responsibility of the owner-user to define life extensions for use
for the bundle life extension methods.
Table 5.3—Bundle Material Cost Factors
Bundle Generic Material
Tube Material Cost Factor,
M
f
Carbon Steel 1.0
C-1/2 Mo 2.0
1-1/4 Cr 2.0
2-1/4 Cr 2.8
5 Cr 3.2
9 Cr 3.3
12 Cr 3.4
70/30 CuNi 3.5
90/10 CuNi 3.5
Monel 400 7.0
Nickel 200 8.5
304/309/310 SS 2.6
304L/321/347 SS 2.8
316 SS 3.0
316L SS 3.0
317L SS 4.2
410/439 SS 2.8
444 SS 3.2
904L 7.0
2205 Duplex SS 3.0
2304 Duplex SS 2.8
2507 Duplex SS 4.0