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Optimal Maintenance Practices for Stationary Equipment: What You Need to Know

Question:

While preventive maintenance plans for rotating machinery are widely available and documented, the necessity of similar plans for stationary equipment such as heat exchangers, furnaces, reactors, and vessels is often questioned. These stationary equipment are typically inspected during turnarounds, which occur every two years. What are the recommended best practices for maintaining stationary equipment? Should they be included in a Preventive Maintenance Program (PMP) or only receive maintenance when necessary? Share your insights on the optimal approach to managing stationary equipment maintenance.

Top Replies

I highly recommend implementing maintenance plans for all your equipment to ensure consistent and standardized work practices. By documenting CM work plans for specific equipment, you can assist system owners and technicians in addressing potential breakdowns, leading to improved reliability. For submersed electric heat exchangers, a megger test is a valuable tool for assessing element condition. Keeping detailed work plans also allows you to easily record data in your CMMS for future reference. In the event of an inspection by a regulatory agency, having a comprehensive CMMS system can be invaluable for showcasing your maintenance history and strategies.

Hello Yahoo, a large percentage of assets are included in the RBI (Risk-Based Inspection) Policy. This policy establishes guidelines for inspection and maintenance frequency based on the asset's condition, rather than having set time intervals for maintenance.

When it comes to stationary equipment like heat exchangers, furnaces, reactors, and vessels, regular maintenance plans are essential. While most of these equipment are inspected during turnarounds every two years, it is crucial to have a maintenance plan in place for ALL equipment. Pressure-containing and structurally-integral parts can be effectively analyzed using Risk-Based Inspection (RBI). However, other parts are prone to age-related failures such as wear, creep, corrosion, or fatigue. These issues are best addressed through regular inspections and maintenance activities. Remember, inspection is a key part of maintenance, and any necessary follow-up repairs should also be considered part of the maintenance process.

In stationary equipment maintenance, age-related failures such as wear, creep, corrosion, and fatigue are common issues that should be addressed proactively. It is recommended to conduct regular inspections to identify and address any potential issues. Some of the equipment that may require attention include boilers, furnaces, heat exchangers, ammonia and carbamate vessels, and other columns. For stationary equipment reliability-centered maintenance (RCM), it is important to refer to guidelines and best practices. While rotating equipment often uses metrics like MTTR and MTBF, RBI as per API standards is typically referenced for stationary equipment. However, RBI provides flexibility in inspection timing, primarily based on thickness criteria. Your input on this is appreciated.

In a previous conversation, Yahoo stated that they conduct inspections on pressure-containing equipment such as boilers, furnaces, heat exchangers, and vessels used for ammonia and carbamate. They mentioned that Risk-Based Inspection (RBI) is applicable to these items. However, for equipment like hoppers and spray atomizers, age-related failure modes may be more prominent, making time-based schedules more suitable. If you're looking for guidelines on best practices for RCM of stationary equipment, some recommended resources include the UK HSE's Research report 3637, ASME's RBI Guideline, and API's RBI Resource Document. While there may not be textbooks specifically on this topic, RBI vendors like DNV and Veritas likely have proprietary documents available.

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While everyone has valid points, one crucial aspect that often goes unmentioned is the significance of experience, particularly from sister plants or similar industry peers. The concept of Recognized and Generally Accepted Good Engineering Practices (RAGAGEP) is endorsed by OSHA, but in its absence, plant-specific experience becomes paramount. The main challenge lies in ensuring you have sufficient documented data to back up your decisions. It's important not to overlook the critical factor of 'operating context' in Reliability-Centered Maintenance (RCM), which is often underemphasized. Remember, industry standards are just that - standard. If your plant operates differently, don't hesitate to make necessary adjustments.

Cliff, your observation raises a valid point. Your comment underscores the importance of processes like Reliability-Centered Maintenance (RCM), which focuses on understanding the operational environment. It is widely believed that the term gained popularity following the groundbreaking work of Nowlan & Heap. Similarly, Risk-Based Inspection (RBI) is a structured approach that emphasizes the operational context. Both RCM and RBI are designed to pinpoint potential failure risks through a systematic approach. Managing risks is at the core of all operational management. You mentioned that standards are just that - standard, but when it comes to RCM and RBI, they are tailored processes that consider specific factors like functions, operating conditions, potential failure modes, and decision-making logic for identifying appropriate maintenance tasks. Unlike manufacturer guidelines or legal requirements, RCM and RBI are not strict directives; rather, they provide a methodology for implementation. In essence, they outline the steps to reach a solution, not the solution itself.

I completely agree with you, Vee. It's important to note that industry standards like ASME and ANSI are crucial. However, the beauty of RCM, PMO, or RBI lies in their adaptability to your specific operating environment. It's even more beneficial when tailored to your unique operating culture. This is a crucial consideration, as some companies have faced challenges when attempting to implement RCM without a well-functioning work order system in place.

Can you clarify the statement "businesses lacking a operational work order system attempt to initiate RCM implementation" in this situation? Thank you.

I have encountered companies that haphazardly jump into Reliability Centered Maintenance (RCM) without being fully prepared, simply because it's a trending practice. This approach can lead to issues like a poorly established Work Order process, tasks being completed without following proper procedures, and inadequate priority setting. A more concerning issue arises when the Asset Register itself is incomplete or contains inaccuracies. Another observation I've made is that some companies overlook the basics, such as ensuring equipment is kept dry, clean, aligned, lubricated, balanced, and properly tightened before diving into RCM implementation. It's crucial to establish a strong foundation before taking on more advanced maintenance strategies like RCM. Walk before you run!

I recently attended a conference where attendees were seeking a magic solution to their issues. Many were looking towards Reliability Centered Maintenance (RCM) as the answer. However, upon discussing their current system with them, it was clear that their existing system was inadequate, lacking in functionality and failing to provide valuable insights. Much of their work was reactionary, without proper work orders in place. A key aspect of RCM is its reliance on data-driven decisions. Without a structured approach to capturing, categorizing, and analyzing work - typically through a work order system - organizations may not be prepared for the implementation of RCM. It is essential to have the foundational elements in place before moving forward. It was surprising to see the popularity of RCM at the conference, especially considering that many could significantly improve their maintenance practices simply by focusing on fundamental principles such as planning, scheduling, analysis, involvement, and empowerment. Some attendees believed RCM alone could solve all their problems, when in reality, their main issue was communication breakdowns. While RCM is a powerful tool, it is important to remember that it is just one tool in the maintenance toolbox. Like any tool, its effectiveness depends on the skill and knowledge of the user. RCM is not a cure-all solution for maintenance problems. It is important to use the right tool for the job, just like you wouldn't use a hammer to drive in a screw. Let's continue this valuable conversation.

Hello Cliff, I completely agree with your statement about the influence of RCM marketing on customer maintenance strategies. Implementing a back-to-basics maintenance approach and fostering effective communication between operators and maintenance planners can decrease equipment failure rates. The timing of implementing the RCM process is uncertain but should be determined by reliability discipline specialists based on achievement objectives. I have experience with RCM processes that were successful when actively tracked and updated to address new failure patterns.

As part of our preventive maintenance program, we regularly perform eddy current testing on steam generators, heat exchangers (HX), and other critical equipment every two years during scheduled shutdowns. This proactive approach helps us ensure the safety and efficiency of our operations while minimizing the risk of unexpected downtime. Contact Irshad for more information.

Dear Vee and everyone, After reviewing the RBI approach, I attempted to persuade my middle management to consider moving equipment to a condition-based inspection schedule rather than including it on every turnaround list. However, they raised concerns about the potential production loss if any equipment fails before a scheduled TA. Do you have any comments or suggestions on this issue? Your feedback is greatly appreciated.

I recently stumbled upon a book discussing the importance of preventive maintenance, which suggests that PM should ideally not exceed 15-20% of the overall workload. What are your thoughts on this recommendation?

The definition of preventive maintenance (PM) can vary, with some interpreting it as a fixed time change out. In our analysis spanning over 20 years of PMO data, we have found that the percentage of PM-related failures is closer to 10-15%. Other discussions on various forums have presented a range of values, which I believe are influenced more by facilitators rather than the direct relationship between plant design, operating conditions, and failure patterns. I recently stumbled upon a book on preventive maintenance that argues PM should not make up 15-20% of the total workload. According to Nowlan and Heap, only 14% of failures are random, nowhere near the 80% figure mentioned by Sam. It appears that some consultants may be misinterpreting the work of Nowlan and Heap, as their study found that 68% of failures were due to infant mortality, which is quite different from random failures. Overall, it is important to understand the nuances of different failure types in order to effectively implement preventive maintenance strategies. Regards, Steve.

I am curious about the link between aircraft failures and failures in other industries such as refineries and manufacturing. With advancements and changes in technology, it's possible that failure trends may vary among different types of equipment. Has there been a comprehensive study on general industry (GI) failures to serve as a baseline for comparison? Have industry consultants confirmed the findings of the Heap & Nolan studies or are there discrepancies? It is crucial to avoid consultants misinterpreting and applying these results inaccurately. The variation in CM-PM ratio numbers suggests that reliability goals and equipment conditions may differ for each plant. Unfortunately, our CMMS system lacks clarity in categorizing failures and inspections. It has been a challenge to address this issue within our Corporate CMMS group, but as a Maintenance Reliability professional, I am committed to overcoming this obstacle. Maintaining reliability in the face of evolving technologies and challenges is indeed a challenge that requires constant effort.

I just recalled that the Society for Maintenance and Reliability Professionals (SMRP) is in the process of releasing baseline metric data. I am looking forward to seeing if they include Nolan & Heap's failure trends in their upcoming publications.

Yahoo explains that after undergoing the RBI approach, they attempted to persuade their middle management to shift towards condition-based inspection instead of including equipment in every turnaround list. However, the middle management raised concerns about potential equipment failures before the turnaround and resulting production losses. Despite the possibility of unexpected equipment failures due to various factors such as delayed or poor quality PM, changes in operating conditions, and ineffective operating practices, it is essential to acknowledge and manage risks proactively. While some failures may be age-related, focusing on age-related maintenance through PM for those specific failure modes is more practical. Addressing non-age related failures through PM may not be as effective and could be a waste of resources. It is crucial to identify risks effectively with strategies such as RBI, RCM, and IPF to mitigate them efficiently. Remember, a significant percentage of failures are attributed to poor maintenance practices, emphasizing the importance of optimizing maintenance efforts to prevent unnecessary failures.

Frequently Asked Questions (FAQ)

FAQ: FAQs:

Answer: 1. Why is preventive maintenance important for stationary equipment like heat exchangers, furnaces, reactors, and vessels? - Preventive maintenance helps to identify and address potential issues before they escalate, ensuring the reliability and efficiency of stationary equipment.

FAQ: 2. What are some recommended best practices for maintaining stationary equipment?

Answer: - Some recommended best practices include regular inspections, cleaning, lubrication, and testing to extend the lifespan and performance of stationary equipment.

FAQ: 3. Should stationary equipment be included in a Preventive Maintenance Program (PMP) or only receive maintenance when necessary?

Answer: - It is advisable to include stationary equipment in a Preventive Maintenance Program (PMP) to ensure consistent upkeep and proactive management of potential issues.

FAQ: 4. How often should maintenance be performed on stationary equipment like heat exchangers, furnaces, reactors, and vessels?

Answer: - Maintenance on stationary equipment should be performed regularly as per manufacturer recommendations, and additional inspections may be necessary depending on the specific operating conditions and usage.

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