What You Need to Know About Damage Mechanism Reviews

ABS Group Technical Inspection and Process Safety Management Services

The California Interagency Working Group on Refinery Safety was formed in 2012, as a response to recent refinery and process industry accidents, to examine ways to improve public and worker safety at petroleum refineries. The objective of the group was to identify means of improving both refinery and agency performances with regard to identifying regulatory gaps, areas of overlap and areas in need of improved coordination. The Interagency Group published its findings in February 2014 in the report "Improving Public and Worker Safety at Oil Refineries."

This study resulted in changes to the accident prevention and process safety requirements as these apply to refineries. The most recent draft of the proposed changes to the Process Safety Management (PSM) Standard requirements was published in July 2016. ABS Group anticipates that the revised and new PSM requirements will become effective in the fall of 2017.

New Damage Mechanism Review Requirements

One of the new elements added to the PSM regulations is the requirement to perform a damage mechanism review (DMR). While industry already conducts damage mechanism assessments and DMRs and has done so for quite some time, this is the first instance in which specific regulations have addressed this topic as an explicit requirement of a PSM program.

DMRs are a systematic analysis process which may be performed on a circuit-by-circuit basis by a multi-disciplinary team of technical professionals and are:

• designed to determine credible damage mechanism susceptibilities of pressure-containing equipment
• used to help formulate inspection plans to mitigate risk of loss of containment and/or unplanned outages

The revised PSM requirement per the California Accidental Release Prevention (CalARP) program / California Occupational Safety and Health Administration (Cal/OSHA) defines a damage mechanism as a mechanical, chemical, physical or other process that results in equipment or material degradation. This includes internal damage that may occur due to process conditions as well as external damage due to environmental conditions. 

Here are the key points relating to the new DMR requirements that you will need to know to comply with the latest PSM regulations:

Application and Timing

Refiners will be required to address DMR for each process in which a damage mechanism exists. Based on our experience, this would be almost every refining process imaginable; however, if you believe that you have a process in which no damage mechanism exists, you will be required to document the rationale for that process according to the new DMR requirements.

In terms of implementation, refiners will have to determine and document a priority order for DMRs. The expectation is that 50% of the processes would have DMRs completed within the first three (3) years and 100% within five (5) years after the effective date of the regulation. In addition, there is a required revalidation of the DMR after five (5) years from the completion of the initial review.

DMR Process

So what is the regulators' expectation for what occurs in a DMR? One is an assessment that involves a review at least at the process flow diagram (PFD) level. Another expectation is to identify all potential damage mechanisms and determine whether or not the materials of construction are both appropriate for their application and resistant to the potential damage mechanisms.

Refiners will need to think about other methods to prevent and/or mitigate damage, such as corrosion monitoring programs and controlling/monitoring process conditions via integrity operating window (IOW) limits. They will also need to review operating parameters to identify operating conditions that could accelerate or otherwise increase damage, or that could minimize/eliminate damage.

In order to understand the new PSM regulations, refiners should assess their own previous experience with the DMR process as well as consider the industry-wide processes and applicable standards, codes and practices as these relate to mechanical integrity.

DMR Team

According to the new requirements, DMRs will need to be performed by a team. This team must include people with expertise in engineering, equipment and pipe inspection, damage and failure mechanisms, process operations and an individual(s) familiar with the DMR process. While this team has similar membership to that of a process hazard analysis (PHA) team, a DMR is a different type of analysis requiring a specific set of skills. In addition, the new CalARP / Cal/OSHA requirements specify that the DMR must be available for consideration during the PHA, implying that the DMR should be performed prior to the PHA.

Types of Damage Mechanisms

What do regulators mean by damage mechanisms? In the revised PSM regulations, they specifically call out that the following types of items/damage mechanisms should be considered, which mirror those referenced in API Recommended Practice 571:

• Mechanical loading failures (such as fatigue)
• Erosion
• Uniform corrosion, localized corrosion and pitting
• Thermal-related failures
• Cracking
• Embrittlement

DMR Report

One of the important questions for industry stakeholders who have conducted DMRs and have this information is how to meet the report requirements. According to the new DMR requirements, the report must contain information regarding process unit and damage mechanism analysis, the results of all analyses conducted and the recommendations for temporarily mitigating damage (for example, confirming materials of construction when this may not be clear during a DMR), and/or preventing damage, such as documenting your corrosion monitoring program or your chemical injection program. As another example of this, we like to set what we call a positive material identification, or PMI, flag during our DMR process. The flag is a safeguard that helps us manage getting the right materials of construction in place.

Incorporating DMR into Other PSM Elements

The DMR requirements also include links to other elements, specifically PHA, management of change (MOC) and employee participation.

New requirements to the PHA topic note that applicable DMRs will be used. The PHA team will also need to consult with individuals with expertise in damage mechanisms when performing the review of applicable DMR reports. This means that someone from the DMR team, probably the corrosion and materials engineer, is going to be part of your PHA team, at least on a part-time basis. The PHA may be supplemented with a checklist to address DMR reports that apply to the process unit.

Incident investigation/root cause analysis (RCA) may also include DMRs, providing a two-way transfer of information between the DMR team and the incident investigation/RCA team. During an incident investigation, a DMR will provide information that needs to be considered. During incident investigation involving a damage mechanism as part of the event or incident, it may be necessary to update the DMR or even generate the DMR for the first time. Put another way, a recent DMR needs to be reviewed if a damage mechanism may be a contributing factor of an incident. A DMR also needs to be performed as part of the incident investigation if a DMR is not available for the process in which the incident occurred. 

There are also changes as to employee participation in the new PSM regulations. This element now includes a requirement that employees must participate in the DMR process and so in order to comply with these new regulations, employee participation plans should be updated to address the DMR.

DMR is also an output to MOC, pre-startup safety review and hierarchy of hazard controls analysis.

How to Address the New DMR Requirements

ABS Group recommends the following path forward for complying with the new DRM requirements:

• Establish and document priority and schedule for performing DMRs
• Consider defining a DMR protocol/management system, especially team and documentation requirements
• For previously completed DMRs, review documentation/results in view of new requirements and upgrade as necessary
• Determine approach and develop tools for using DMRs in PHAs
• Revise other PSM elements/practices to address DMR requirements

Damage Mechanism Review Webinar Available

For more information about how to perform a DMR as well as how to use a DMR to improve process safety, request access to our webinar, "Cal/OSHA's PSM Regulation: Damage Mechanism Reviews," which details ABS Group's DMR process and solutions.