Condition Monitoring Locations (CMLs) are designated locations on pressure vessels and piping where thickness measurement inspections (TMIs) are conducted to monitor the presence and rate of damage and corrosion.
Most CMLs consist of at least one examination point, usually a two to three inch diameter circle on the surface of the equipment. It’s within these circles that the inspection takes place. The number of specific spots where individual readings are taken within these areas varies. API 510 and API 570 recommend recording either the lowest or an average of several readings within the area of the examination point.2,3
The number and location of CMLs needs to be a sampling that covers the entire population range. Additionally, the number is based on the user’s desired confidence in the sample data. In other words, more CMLs will produce more sample data, which, in turn, should increase a user’s confidence in the estimated condition. More locations should be used to monitor higher risk equipment. For sites that have implemented risk based inspection, the number of CMLs will typically depend on the desired level of risk mitigation.
Prior to the 9th edition of API 510 and 3rd edition of API 570, a thickness measurement location (TML) referred to a single examination point where thickness measurements would be performed in order to establish general and localized corrosion rates. Whereas a CML can include one or more of these points, CMLs now include what were previously referred to as TMLs. Upon publication of the 9th edition of API 510 and 3rd edition of API 570, API codes no longer use the designation TML independent of CML.
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November/December 2017 Inspectioneering Journal
By Geoff Clarkson at UTComp, Inc.
This article, part two in a series, provides a case study of an inspection and evaluation of a Fiberglass Reinforced Polymer (FRP) column using nondestructive ultrasound readings on the outer surface of the FRP. |
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May/June 2017 Inspectioneering Journal
By Ryan Myers at PinnacleART, and Brian Marino at PinnacleART
Effective condition monitoring location selection is a key component of a best-in-class mechanical integrity program. Learn how moving beyond traditional qualitative approaches to optimized CML selection can reduce risk and maximize the value of each inspection. |
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March/April 2017 Inspectioneering Journal
By Fernando Vicente at ABB, and Laza Krstin at ABB
Myths, challenges, and good practices related to process piping integrity management activities that help inspection and maintenance managers make the right decisions to develop cost-effective piping inspection plans without compromising the asset’s reliability or performance. |
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January/February 2017 Inspectioneering Journal
By Israel D. Martinez at ORPIC
Evaluating remaining wall thickness of an asset is not enough to ensure its continued safe operation. Proactive strategies should be implemented to assess the entire environment affecting an asset’s condition, including the development of more effective inspection plans. |
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November/December 2016 Inspectioneering Journal
By Loganatha Pandian at Meridium, Inc.
This article summarizes seven key questions that an organization needs to answer to create a robust mechanical integrity program that is properly designed to monitor corrosion and indicate when issues increase to a level requiring review or maintenance. |
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Partner Content
Industrial Rope Access is a proven method of achieving a safe work position at elevated heights or areas that are difficult to access. When combined with advanced NDE technologies, rope access technicians can substantially reduce the cost of inspections and maintenance activities by virtually eliminating the need for fixed scaffolding. |
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November/December 2016 Inspectioneering Journal
By Marc McConnell, P.E. at Pro-Surve Technical Services, and Grady Hatton at Versa Integrity Group
The concept of reducing Condition Monitoring Locations (CMLs) is misguided, and the number and location of CMLs should be OPTIMIZED, not systematically reduced. CML allocation in piping requires a good process, otherwise, you can run into a lot of dead ends before arriving at your intended destination. |
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July/August 2014 Inspectioneering Journal
By A.C. Gysbers at The Equity Engineering Group, Inc.
One of the more common inspection monitoring programs for pressure vessels is to perform thickness measurement at Corrosion Monitoring Locations (CMLs) to allow monitoring of minimum thicknesses and provide estimates for corrosion rates. These minimum thicknesses and corrosion rates are critical in supporting risk based inspection techniques or in setting half-life prescriptive re-inspection intervals. |
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Blog
January 6, 2014 By Nick Schmoyer at Inspectioneering
In 2013 Inspectioneering published content covering a wide array of topics, from risk-based inspection, to advanced nondestructive testing methods, to pipeline integrity management systems. Last year, we published more content than any year prior; we expect the same trend to continue into 2014. |
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Blog
July 1, 2013 By John Reynolds at Intertek
I will emphasize the systems, work processes and procedures for identifying and controlling the rate and types of deterioration in pressure equipment. These are not in any particular order, as they are meant to operate interdependently. |
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Blog
July 1, 2013 By John Reynolds at Intertek
I will emphasize the systems, work processes and procedures for identifying and controlling the rate and types of deterioration in pressure equipment. These are not in any particular order, as they are meant to operate interdependently. |
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May/June 2013 Inspectioneering Journal
By A.C. Gysbers at The Equity Engineering Group, Inc.
Piping failures still represent a frustrating and ongoing problem for processing plants. Failures are still commonly reported and contribute to large losses. In the author’s experience, piping represents the highest percentage of fixed equipment failures in petroleum refining. |
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November/December 2012 Inspectioneering Journal
By A.C. Gysbers at The Equity Engineering Group, Inc.
Piping failures still represent a frustrating and ongoing problem for processing plants. Failures are still commonly reported and contribute to large losses. In the author’s experience, piping represents the highest percentage of fixed equipment failures in petroleum refining. |
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November/December 1998 Inspectioneering Journal
By Michael Twomey at CONAM Inspection Inc., and Jay N. Rothbart at Conam Inspection Inc.
We have been asked many times by existing and prospective users of PCMS (a computerized, inspection database management system), how many TMLs (Thickness Management Locations) should be installed per piping circuit. These inquiries must be addressed indirectly, because each specific site differs in its operation, mission and objectives. We firmly believe it is up to each site to make choices based upon their own circumstances. When pressed on the issue we have pointed toward a couple of papers published or generated within our User Community. While these provide cookbook methods, they do not encompass all the issues facing the User Group. Based upon the continuing questions in this area we decided to provide a review of the issues. |
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September/October 1997 Inspectioneering Journal
By Michael Twomey at CONAM Inspection Inc., and Jay N. Rothbart at Conam Inspection Inc.
This task though tedious and exasperating is a key part of the operation. Plant personnel often find ingenious uses and filing systems for key data such as UW 1 forms. The more remote the plant site is, the more extraordinary the hiding places. In addition, the adage "garbage in = garbage out" keenly applies. To avoid this concern, it is vital to quality assurance check the data prior to input. |
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Sentinel Integrity Solutions is a full service inspection company, providing a full suite of inspection support to service the Petroleum (upstream, midstream and downstream operations), Chemical, Power and Pipeline Industries. We are respected by our clients for the unsurpassed reliability, dedication and professionalism exhibited by our personnel and the customer service and responsiveness exhibited by our Management Team.
Pro-Surve Technical with subsidiaries ProSource Radiography and ProForce Industrial are an integrated inspection, NDT, reliability engineering, Data management and project controls service provider assisting clients across CapEx/OpEx budgeted projects processes. We concentrate on solutions provided by the integration of engineering and inspection.
Pro-Surve Technical with subsidiaries ProSource Radiography and ProForce Industrial are an integrated inspection, NDT, reliability engineering, Data management and project controls service provider assisting clients across CapEx/OpEx budgeted projects processes. We concentrate on solutions provided by the integration of engineering and inspection.
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PK Technology is a full-service inspection contractor, as well as, an in-house software development company specializing in the Oil and Gas industry. PK Technology is the creator of intelliSPEC, the worlds first Digital Data Management System (DDMS) which is a robust and intelligent solution designed to digitize, analyze and realize all vital data.
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Versa Integrity Group, Inc. is a full service inspection, maintenance, and engineering company serving the oil refining, chemical processing, and offshore industries. Versa possesses over 70 years of NDE inspection, engineering and rope access experience and provides its customers access to a total of more than 400 engineers, API inspectors, rope access climbers and NDE technicians. Like many companies, Versa has the tools to get the job done; what separates Versa from the rest of the pack is their commitment to professionalism, integrity, and above all else, customer service.
