Chemical Engineering March 2014 - 42

Inspection
decision
Inspector to determine:
a. advanced NDE
b. insulation removal
c. engineering analysis
d. combination of a, b, c options
If stainless-steel
asset, perform
localized
penetrant-test
exam
NO
Carbon steel
asset with
corrosion scale
or pits
NO
Does
Is
wall loss
greater than
corrosion
allowance?
YES
Inspect 100%
of carbon steel
asset with ANDE
NO
the piping
cross waterway?
Is the piping a class 1
or class 2 circuit?
Is the calculated riskbased
inspection
consequence
A or B?
YES
Perform ANDE
YES
Is
asset
suitable for
advanced
ANDE?
Note 1:
1. If there are additional findings, then follow-up inspection will be required in accordance
with this process. If there are no additional findings, then spot repairs will be completed
and inspection results documented in the asset inspection files.
Figure 4. If corrosion is observed at suspect CUI locations, more in-depth assessments,
probably involving advanced non-destructive testing methods, are undertaken
able for the rope access team to use
for anchoring their ropes. The field
assessment can determine where
rope access would be effective and
which NDE method will yield the
most significant data at the right
cost level. Figure 2 is an example of
the logic flow the field team can follow
to determine the most effective
inspection and test methodology.
The field walkdown team should
pay particular attention to:
* The bottom of horizontal lines
in piping systems susceptible to
CUI
* Any break in the vapor retarder
on cold lines
* Damaged or missing insulation
jacketing
* Location where inspection plugs
have been removed
* Piping systems with deteriorated
coatings or wrappings
* Termination
of
insulation
at flanges and other piping
components
Phase 3
Phase 3 of the program should consist
of the most effective and efficient
methods of testing and inspection
for the detection of CUI. Inspection
and testing findings can be evaluated,
and additional inspection and
testing needs can be quickly determined.
Recommendations can then
be developed to address those issues
that were identified in the previous
phase. Vessel and piping repair
plans can be developed and next
inspection dates set. Figure 3 is an
example of a logic flow for Phase 3
that the testing and inspection team
can use during the screening part of
the implementation phase.
It is not economical or feasible to
expect that the inspection and testing
will cover 100% of the equipment
and piping susceptible to CUI.
Screening inspections and testing
will be conducted to identify suspect
areas. Once these areas are identified,
the decision will be made on
Summary remarks
CUI is a serious hazard affecting
the safety and reliability of chemical
plants, petroleum refineries,
midstream terminals and just about
all oil-and-gas operating facilities.
To best address the problem, CUI
must be addressed in a systematic
or programmatic approach. The
program must be fully defined and
staffed with qualified personnel. Effective
and economical inspection
and testing methodologies should
be utilized as part of the CUI detection
program. By addressing CUI
effectively, the risk of operations
is reduced significantly and the
equipment and plant reliability is
increased. A safely and reliably operating
facility is the product of a
proactive CUI program.
■
Edited by Scott Jenkins
Author
Russ Davis is the National
Asset Integrity Management
Services (AIMS) manager in
the services division of the
Mistras Group Inc. (4000
Underwood Road, LaPorte,
TX 77571; Phone: 281-4781636;
Email: Russ.Davis@
mistrasgroup.com). Davis
has spent over 26 years in
mechanical-integrity program
development and
implementation. His experience includes pressure
vessels, aboveground storage tanks, and
piping inspection, testing and evaluation. Davis
has an extensive background in process safety
management, including hazard assessment and
consequence evaluation. He has developed and
directed mechanical integrity (MI) programs for
a global chemical company. Davis has served as
an MI consultant, as well as external consultant
for the implementation of MI programs. He
has a solid working knowledge of NDE, damage
mechanisms, and materials of construction for
equipment in the petroleum refining, chemical
and energy industries. He is also experienced
in equipment failure analysis, lifecycle analysis
and failure frequencies. Davis is an API-certified
inspector, an ISA 84 Fundamentals Specialist
and a certified safety professional.
ChemiCal engineering www.Che.Com marCh 2014 43
NO
Document
and close
Strip the larger of:
a. all suspect
and damaged
insulation
locations;
b. 20% of asset
area/length
YES
SCC crack
present
YES
Perform
additional
inspections
the most effective and economical
method for follow-up inspections.
Figure 4 is a logic flow for determining
whether or not follow-up inspections
should be performed, as well
as if advanced non-destructive evaluation
(ANDE) methods should be
used in lieu of insulation stripping.
It is costly to remove and replace insulation,
especially if it is not fully
necessary. In many cases, the most
economical method could be an
ANDE method. The advantages and
disadvantages of ANDE methods
are also discussed in Table 1.

http://www.Che.Com

Chemical Engineering March 2014

Table of Contents for the Digital Edition of Chemical Engineering March 2014