Changes Contained in the 10th Edition of API 510, Pressure Vessel
Inspection Code: In-Service Inspection, Rating, Repair, and Alteration
By Vincent A. Carucci
The 10th Edition of API 510 was issued May 2014 and replaces the 9th
Edition. The following summarizes several of the key changes. Please refer
to the original document for details.
Section 1 – Scope
- Vessels that have been abandoned in place and no longer an asset
of record from a financial/accounting standpoint are no longer covered
by API 510. This relieves the owner from continuing to include these
vessels in its overall inspection program. However, should it be
decided later to put the vessel back into service, then its condition
must be evaluated and meet API 510 requirements.
- A new paragraph indicates that the inspection program should
provide reasonably accurate and timely assessments to determine if any
changes could compromise continued safe operation. It further requires
owner/users to respond to any inspection results that require
corrective actions. These areas should have been obvious and
automatically included in any inspection/maintenance program.
Section 2 – Normative References
The title of this section has been changed, but its intent has not.
Several additional references have been added (e.g., API RP 583, RP 584,
RP 585, RP 939-C, ASME PPC-2, etc.)
Section 3 – Terms, Definitions, Acronyms and Abbreviations
Here again, the title of this section has changed but its intent has not.
There are now 73 definitions vs. the previous 62, and commonly used
acronyms and abbreviations have been added.
Section 4 – Owner/User Inspection Organization
- New paragraphs have been added that require management to ensure
that inspectors have an annual vision test and can meet specified
- Para. 4.1.3 – New paragraph covers Management of Change (MOC) and
makes the owner/user responsible for implementing and executing an
effective MOC process that reviews and controls changes to the process
and the hardware. Items to be included in the MOC process are
- Para. 4.1.4 – New paragraph covers Integrity Operating Windows
(IOWs). The owner/user is responsible for implementing and maintaining
an effective program for creating, establishing, and monitoring IOWs.
IOWs make the connection between physical and chemical process
parameters and their potential impact on equipment integrity if not
- Para. 4.6 – Other Personnel. This has been expanded and now
provides examples of potential issues that may affect vessel integrity
that “other personnel” should notify the inspector or engineer about.
- Para 4.7 – New paragraph requires that each owner/user
organization be periodically audited to determine if the authorized
inspection agency is meeting API 510 requirements. The audit team
should typically be from another owner/user plant site, a central
office, or an experienced third party organization.
Section 5 – Inspection, Examination, and Pressure Testing Practices
- Para. 220.127.116.11 – Additional sources of data to be considered in
determining required inspection intervals have been added (e.g.,
extent of previous examination, recent operating history, MOC records,
- Para. 5.2.1 – Mentions that identifying IOWs for key process
variables is a useful adjunct to RBI.
- Para 5.2.2 – Has additional factors to be considered in an RBI
probability assessment (e.g., both the pressure retaining and
structural requirements, past and projected operating conditions).
- Para. 5.2.5 – Has been edited to also require that an RBI
assessment be updated anytime an unanticipated failure occurs due to a
- Para. 5.3.4 – Covers vessel entry and has several additional
requirements that mention following site and jurisdictional safe entry
requirements, inspector responsibilities to know and follow safe entry
- Para. 5.4.1 – Now makes direct reference to API 571 regarding
common damage mechanisms, and expands the list of examples that are
- Para. 5.4.4 – New paragraph provides considerations for evaluation
of vessels that are in cyclic service.
- Para. 5.5.1 – Added that “operator surveillance” be included in
inspection plans. It also now requires that damage identified during
inspections “shall be characterized, sized and evaluated.” By this
last addition, should there have been a doubt before, inspection
results cannot be just filed and forgotten but must be evaluated.
- Para. 18.104.22.168 – Now permits properly qualified personnel other
than inspector (e.g., NDE examiner) to assist, but not replace, the
inspector for internal vessel inspection. Inspections done from a
manway or inspection port may only be done when the vessel cannot be
- Para. 22.214.171.124 – Lists issues that could limit the effectiveness of
using external, onstream inspection techniques to identify internal
- Para. 126.96.36.199 – Additional considerations are provided with
respect to the excavation and external inspection of buried pressure
- Para. 188.8.131.52 – Now explicitly states that the inspector shall
review the results of the thickness inspection data to look for
- Para. 184.108.40.206 – Adds duplex stainless steel material and
associated temperature range for its susceptibility to CUI. Reduces
maximum temperature for austenitic stainless steel CUI susceptibility
from 400°F to 350°F.
- Para. 220.127.116.11 – Adds reference to API 583 for more detailed
information on CUI.
- Para. 18.104.22.168 – Additional considerations for insulation removal
to inspect for CUI are added.
- New Para. 5.5.7 – Highlights operator surveillance during their
normal duties as a means to identify to the unit inspector anything
unusual associated with pressure vessels and pressure relieving
devices. This is comparable to what API-653 requires for aboveground
atmospheric storage tanks.
- Para 22.214.171.124 – Adds reference to API 579-1/ASME FFS-1 in cases
where detailed thickness reading grids are needed to perform FFS
assessments of metal loss.
- Para. 5.6.3 – provides additional guidance for the selection,
number, and placement of CMLs.
- Para. 5.6 3 – Provides additional guidance for the selection,
number, and placement of CMLs.
- Para 126.96.36.199 – Adds hardness measurements and advanced ultrasonic
backscatter examination as possible examination techniques to
consider. It also references API 572 and API 577 for additional
- Para. 188.8.131.52 – A caution was added to ensure that all instruments
and components that will be subjected to the hydrotest pressure are
either designed for it or blinded off from the test.
- Para. 184.108.40.206 – More details are provided for cases where a
hydrotest will be done on equipment having components of Type 300
- Para. 5.8.6 – Adds reference to ASME PCCC-2 for pneumatic test
- New Para. 220.127.116.11 – Requires that the water temperature not exceed
120°F when hydrotesting solid or clad austenitic stainless steel
vessels to prevent possible chloride stress corrosion cracking.
- Para. 18.104.22.168 – Advises that an FFS assessment to identify
critical flaw size(s) should be conducted to specify acceptance
criteria when NDE is used as an alternative to pressure testing for
repairs or alterations.
- Para. 5.11.2, 5.11.4 and 5.11.5 – Have additional details
regarding the inspection and repair of flanged joints.
Section 6 – Interval/Frequency and Extent of Inspection
- Para. 22.214.171.124 – Adds a requirement that if vessel damage is found
during inspection done at the time of installation, it be documented
and recommendations made for appropriate repairs or engineering
- New Para. 6.3.4 – Requires that RBI assessments be per API RP 580.
- Para. 6.4.2 – Adds external inspection requirements for equipment
that is retired and abandoned in place.
- New Para. 126.96.36.199 – Provides inspection requirements when
comparing vessels having the same or similar service. This approach
could be considered in order to use onstream inspection instead of
- Para. 188.8.131.52 – Adds a requirement that the QA manual for an
organization that repairs pressure relieving devices include
requirements for shop auditing for adherence to the QA process.
- New Paras. 6.7, 6.8, and 6.9 – Provide requirements for deferral
of inspection due dates, deferral of inspection repair recommendation
due dates, and review of inspection repair recommendations.
Section 7 – Inspection Data Evaluation, Analysis, and Recording
- Para. 184.108.40.206 – Has been expanded to provide considerations to
determine what corrosion rate should be used for determining remaining
life and next inspection due date.
- Para. 220.127.116.11 – Adds criteria that must be met in order to use
thickness averaging to evaluate corroded areas of a considerable size.
- Para. 18.104.22.168 – Has been expanded to provide thickness averaging
requirements near structural discontinuities, not just for near
nozzles as was the case before.
- Para. 7.4.3 – Now adds reference to API 579-1/ASME FFS-1 for
Section 8 – Repairs, Alterations, and Rerating of Pressure Vessels
- Para. 8.1.5 – Adds cautions if need to weld carbon steel having a
carbon content over 0.30%. It also indicates that PMI should be
specified if the inspector has any questions about material
- A new Figure 8.2 – Provides a sample additional nameplate (or
stamping) that must be installed in a rerated pressure vessel.