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Hello Brighton, I am initiating this new discussion thread, as per Steven's suggestion. I will make an effort to address all your inquiries, but if I overlook any, please bring them to my attention. One query I have is regarding swapping over to the duty pump after running the standby one for a day. Can you confirm if this is what you had in mind? Answer: Yes. Another important aspect to consider is the maintenance strategy for critical equipment such as compressors and compressor after coolers. Your insights on this matter are highly valued. Answer: For reciprocating compressors with soft gland packings, a weekly switchover may be necessary to ensure proper lubrication. On the other hand, centrifugal or screw compressors, or reciprocating compressors with mechanical seals, should be operated on a duty/standby basis similar to pumps. Could you provide recommendations on the mechanical services available to improve equipment performance? For instance, how can thermography be utilized to detect issues like hot bearings, damaged insulation, or faulty steam traps? The potential applications are extensive. We are considering a plant shutdown followed by three years of operation. How will this impact the duty-standby approach for pump operation? Answer: There should be no conflict. Before implementing any new strategies, it is crucial to understand the rationale behind them. This requires thorough research through books, articles, papers, and discussions with operators, maintainers, and industry experts. Making decisions based solely on online discussions may not yield the best results.
When transitioning to standby mode, it is often necessary to have a "hot" backup ready for duty. This approach varies depending on the equipment being used. For example, a backup compressor can be put into unloaded operation before entering sleep mode, while a backup boiler must maintain pressure to quickly switch into operation. Refinery pumps used for hot service with mechanical seals may have a bypass from the suction to the discharge line with a check valve. During hot standby, this valve should be slightly opened to allow for slow rotation of the pump shaft. Any thoughts on this strategy?
In cases 1 and 2, the hot standby operates as a secondary mode under no or light load conditions, rather than the typical duty-standby operation. This mode only experiences some, but not all, degradation mechanisms compared to the primary operation. For example, think of a cruise liner cruising smoothly in calm weather versus navigating through ports or berthing, which puts high loading on all systems. When analyzing these dual modes, it's important to consider the percentage of time spent in each mode to develop an effective strategy. Traditional duty/standby approaches may not be suitable. In case 3, the motor is inactive with no load on the pump, simply being kept warm and sometimes rotated with barring gear. This is considered a standby mode, where duty/standby strategies are applicable.
Thank you, everyone. It's unfortunate that the pumps are swapped weekly at my workplace. This practice may not be ideal. I haven't had a chance to review any vendor manuals, so I'd like to ask the following question here: How can we ensure the standby equipment's integrity while running the duty one as much as possible? It's important to ensure that the standby equipment is ready to come online when needed.
One important question to consider is the frequency of vibration analysis (VA) conducted by a third-party company every quarter. While this may be beneficial, it is important to also have a plan for monitoring equipment in between these VA surveys. What proactive measures can be taken to ensure equipment is accurately monitored and maintained between scheduled VA assessments?
It is important to regularly monitor equipment in between two Veterans Affairs (VA) surveys, as the surveys themselves are a crucial component of the monitoring process. Keeping a close eye on the equipment during this time is essential for maintaining optimal performance and ensuring compliance with VA regulations.
I completely agree with you. When it comes to critical equipment like compressors and aftercoolers, a holistic maintenance strategy is paramount to ensure longevity and efficient operation. Thermography is indeed a valuable tool to foresee issues such as damaged insulation or faulty steam traps, not just in mechanical services but in electrical applications as well. Also, I believe a plant shutdown would indeed offer a great opportunity to reassess current strategies in place. There's no one-size-fits-all solution here, and local conditions must be thoroughly analyzed. You're spot on about not relying solely on online discussions. They're a great starting point, but diving into more comprehensive research materials and professional consultations is definitely a must for better informed decisions.
Brighton, your inquiries have already been answered in previous discussions. Please take a moment to revisit them to avoid redundant explanations. I previously elaborated on how to sustain the initial integrity, using the analogy of a horse and cart. Have you had a chance to review that explanation?
Vee, I recall your insightful analogy of the horse and cart; however, I am seeking information on a different topic. Our plant currently lacks vib tech capabilities, so I am eager to implement continuous machine monitoring by our plant technicians in addition to our quarterly vib surveys. 1- What are some fundamental maintenance tasks that our technicians can perform? 2- In the event that the vib technician checks a standby machine and we switch to the duty machine, it could be problematic if the standby machine fails to start when urgently needed the next day due to an unexpected issue with the duty machine. How can we prevent this scenario and ensure that the standby machine remains reliable for service? Thank you.
FAQ: What are the essential maintenance tasks for technicians to perform? Keeping machinery clean and properly lubricated is crucial for preventive maintenance at our facility. Routine checks during maintenance include inspecting for loose bolts, checking alignment, monitoring oil levels, clearing clogged filters, identifying rubbing parts, listening for strange noises, and securing loose electrical connections. It seems like you may be waiting for guidance on equipment maintenance. Remember, neglecting maintenance tasks could lead to major issues, as my boss used to say: "It's better to mess up while fixing a machine than to do nothing and have the machine fail."
Steven, I appreciate your attention to detail in checking the machine against the specified items. However, I am curious if there are any specific and crucial details we should be aware of. Could you please provide information on the process of changing the oil in a standby pump? This will ensure that we are well-prepared for any maintenance tasks that may arise. Thank you.
In areas with extremely low humidity and where you can confidently verify that the back-up pump is not in use to prevent dirt ingress or product contamination, opting for a yearly replacement is advisable. However, if these conditions are not met, it is more practical to schedule a replacement every 3 to 6 months for easier management.
If you're looking for the best strategy for managing vibration analysis and maintenance schedules, make sure to check out the thread titled "Best Strategy" by RCM2 in the Brighton forum. The thread contains numerous helpful suggestions to consider. When developing your strategy, it's important to reassess the frequency at which vibration analysis technicians come in. This frequency should align with your duty/standby regime to ensure timely responses to equipment issues. Additionally, consider incorporating maintenance interventions into the vibration analysis schedule to maximize efficiency. If you have any questions about technician responsibilities, remember that they typically handle all preventive maintenance tasks, as well as non-vibration condition monitoring activities like lubricating oil sampling and thermography. If you need further clarification, refer back to previous discussions on the topic.
Hey Vee, I'd appreciate it if you could clarify the meaning of MTBF in this scenario. Specifically, how will the MTBF of pumps increase by around 10% if...
Following your suggestion, I have started delving into the discussion on the "Best Strategy." However, I may have a few inquiries that I kindly ask for your patience in addressing. There are essential maintenance tasks that should be conducted regardless of the operating policy, such as oil top-ups, cleaning, and taking vibration readings. These tasks are considered part of routine housekeeping or preventive maintenance activities. Invasive work, on the other hand, is only necessary if a fault is detected during a test start. How frequently should this test start be performed? Would it be suitable to schedule it every three months when vibration specialists are on-site?
In Brighton, the Mean Time Between Failures (MTBF) is a crucial indicator of reliability. A higher MTBF results in fewer failures, leading to longer operational runs and improved availability, ultimately reducing costs.
Brighton, I have already explained that you should test start every 2 months, with the possibility of extending it to every 3 months in some cases. It is safer to stick to testing every 2 months initially. It is important that vib readings are taken at least every two months if tests are conducted every 2 months. I don't understand why you are fixated on your vibration monitoring team's schedule. They should be able to come every two months instead of being tied to a quarterly contract. If needed, the old contract for vib readings should be torn up and rewritten. The frequency of testing should not be determined by the outdated contract.
In Brighton, do you know what kind of plant this is? Are services available 24x7x360 or 5x8? And are the vibrational analysis technicians compensated per measuring point? Personally, I don't have an issue with this payment structure; however, if I were the one footing the bill, I would prefer a payment system based on performance and reporting.
Based on my perspective, utilizing the duty/standby system results in optimal reliability, availability, and cost-effectiveness. Vee, it appears that your recommendation is to run the duty until it fails, at which point you switch over to the standby option. Can you please verify this for me? I am still learning, so I apologize for any additional questions I may have. Thank you! Best regards.
In order to maintain the optimal performance of pump systems, it is essential to follow a strategic maintenance schedule. Rather than simply running a duty pump until it fails, it is important to regularly monitor its condition and intervene before any issues arise. Established warning and fault limits should be observed to ensure the pump's longevity. Additionally, the standby pump should be tested periodically to ensure its functionality under normal working conditions. A recommended schedule is to run the main pump for 12 weeks followed by 3 weeks off, while the backup pump runs for 12 weeks off and 3 weeks on. This rotation allows for continuous monitoring of both pumps and ensures that the backup is operational when needed. Frequent start-stop cycles should be avoided as they can lead to premature failures. It is crucial to avoid running the main pump until it fails, only to realize that the backup pump is not functional. By incorporating regular maintenance and testing into the pump system schedule, the risk of unexpected failures can be minimized.
Steven, I appreciate your response. Following the schedule of 12 weeks on and 3 weeks off deviates from the duty/standby policy Vee introduced, which observes a ratio of 90:10. Could you please provide clarification on this matter? Thank you.
When you calculate 12 weeks on and 3 weeks off, you get an efficiency of 83-17%. However, with 12 weeks on and 2 weeks off, the efficiency increases to 90-10%. It's clear that these schedules are better than having complete darkness (100-0%) or needing to replace both pieces of equipment simultaneously (50-50). Doing the math shows the importance of regular maintenance and scheduling for optimal performance.
Implementing a 90:10 policy or a similar approach eliminates the worry of 'fail-to-start' as a potential failure mode. Vee, can you please provide a detailed explanation?
Hi Steven, could you please clarify the duty/standby concept for me? I'm also curious about the operation/idle percentage.
The Operation/idle ratio is calculated by dividing the Duty Standby percentage. This assessment is made over a year (52 weeks) period, where Duty is planned to be operational 83% of the time, while Standby is active 17% of the time.
Hello Steven, Imagine the scenario where the pumps are in duty/standby mode, but due to a sudden issue like a leakage in the duty pump, the standby pump is activated. The duty pump is scheduled to be fixed in 3 days; will it automatically take over once repaired? Cheers!
Posted on 05 May 2006 at 10:43 AM. The first pump, also known as the main pump and duty taker, has the ability to cannibalize the other two pumps. The second pump serves as a standby option, cannibalizing only from the third pump. The third pump acts as a storage point located beside the other pumps, with its main purpose being to keep parts easily accessible for the first and second pumps. Its hours of operation are minimal. Steven, can you confirm if Eugene's post above is accurate?
Have you ever wondered what goes on in the world of pump systems? Typically, there is one primary pump and two backup pumps in operation. In the event that two pumps are in use and one is on standby, the system can still be managed effectively, despite potential challenges. It is important to be prepared for any unforeseen obstacles that may arise.
Steven: Are cannibals easily recognized by their large, menacing teeth?
"When facing a fixed deadline of 3 days for a duty, your flexibility will determine the best course of action. If it aligns with the service period of the Main pump, it's ideal to conduct the repair during the scheduled maintenance. Otherwise, restarting the main pump would be the recommended next step."
Vee mentioned that an idle standby pump has a crucial hidden failure mode where it may fail to start or not function at full capacity. To ensure its reliability, it is necessary to start the pump, put it under load for a few hours, and conduct a test start or follow a 90:10 policy. Opting for the 90:10 policy involves testing the start and running the standby pump for a few hours. This approach helps minimize the number of starts to maintain the mechanical seals in optimal condition. Steven, could you please provide further clarification on this matter?
Hello everyone, I apologize for joining the conversation late, but I have a suggestion that may be helpful. Brighton, have you considered implementing a fixed switch over policy, such as a ratio of 90:10, and using simple machine condition detection tools to monitor machine condition between vibration surveyor visits every three months? While I believe three months may be too frequent, if there is no change in machine condition over that period, it should not be a major issue. I recommend starting with a shorter time interval, like one or two months, until you have enough data to justify increasing the interval. Your feedback on this idea would be appreciated.
Steven, in terms of the pumps being equipped with Mechanical seals, I plan to implement the following strategies: a) For pumps handling chemicals such as Glycol 12w running and 1w off for duty, and 12w off and 1w on for standby. b) For pumps handling hot chemicals and hot oil at around 150°C, 12w on and 4w off for duty, and 12w off and 4w on for standby. Your feedback is appreciated.
I really enjoyed your concept, Ahmed. Cheers!
Ahmed from Brighton raises a valid point about the 3-month run not being the ideal starting point. I recommend starting with a schedule of 7 weeks on and 1 week off for your trials. You can find an article in the October issue of Uptime discussing duty/standby operations, where I delve into the rationale behind this approach. I encourage you to read this article for further insight.
Welcome back, Vee! I'm excited to hear you're considering purchasing your book. Could you please advise if it is suitable for beginners in maintenance? I would appreciate it if you could answer the following questions: 1- When operating high pressure reciprocating plunger pumps, is it still recommended to follow the 90/10 Policy? 2- If a pump with a mechanical seal that is on standby experiences a fault, such as a labyrinth seal leak, is it safe to test run it after repairs have been made? And how long should it be kept online? 3- You recommended using a 75% Duty 25% Standby for Hot Oil pumps (7W On/2W Off). There are 1/2" tubing lines from the common discharge of the pumps into the pump casing, with a temperature of around 150c. Will this cause any issues for the pump or seal? Thank you.
I wanted to inform you that the manufacturing plant I manage has been operational for 18 months. Previously, technicians were frequently changing out pumps every month. However, I implemented a new approach to prevent this practice. Best regards.
Hello Brighton! I've included my responses in italics. A user posted on September 19, 2006 inquiring about the benefits of my book for beginners in maintenance. I apologize for my absence due to business engagements. There are numerous excellent books on maintenance that you should explore. Here are answers to your questions: 1- When operating high pressure reciprocating plunger pumps, should the 90/10 Policy be followed? The frequency depends on whether the glands are packed with soft packing or a mechanical seal. For soft packing, run every other week. 2- If a pump with a standby mechanical seal experiences a fault, such as a labyrinth seal leak, is it safe to test run it after repair? The repaired unit must undergo a test run of 2-4 hours to ensure the leak is fixed. 3- Regarding the use of 75% Duty 25% Standby for Hot Oil pumps (7W On/2W Off), this ratio pertains more to starting complex equipment rather than specifically hot or cold oil. The 1/2" tubing lines from the common discharge of the pumps into the pump casing at a temperature of around 150c should be reviewed in the manual for any potential issues. It is essential to understand the function of these tubing lines to determine their impact on the pump and seal. I recommend consulting the vendor's manual for more information.
Thank you for your response. I am inquiring about pumping hot oil at a temperature of 150C with pumps equipped with mechanical seals. Should the pumps be operated at a 90/10 ratio or does the type of media being pumped play a role in this decision? I value your insights.
In the upcoming October edition of Uptime, look out for my insightful article on duty/standby operations. I delve into the rationale behind this process, so I highly recommend giving it a read. If you haven't come across the article yet, please send it my way. Thank you and best regards.
Can you believe it's already September in Brighton? It seems like time is flying by! Let's dive into this article and see what's in store for this month.
In Brighton, mechanical seal pumps are a must-have. While most media types work well, there are a few exceptions, with hot oil being a notable one. Keep an eye out for the upcoming October issue for more information on this topic. Stay tuned for the latest updates!
Thank you, Vee! I can't wait to read your article. Best regards.
When it comes to operating high-pressure reciprocating plunger pumps, the decision to adhere to the 90/10 Policy hinges on whether the glands are equipped with soft packing or a mechanical seal. If soft packing is used, it is recommended to run the pumps every other week. Currently, we have four high-pressure plunger pumps distributing glycol to two wellheads. Each well is assigned two pumps, with a rotation every three months, resulting in two pumps remaining idle for three months at a time. While this practice has been in place for almost 2 years, I am unsure if it is the most effective approach. Given that the pumps discharge to two separate common headers, I am seeking recommendations on how to maintain the idle pumps. Your insights would be greatly appreciated.
Switching them out every 3 months follows a 50-50 operating protocol. This process has been in place for close to 2 years, but I question its validity. Why is this practice still being maintained?
The ongoing debate aims to demonstrate why a 50-50 split is not the optimal solution!
Are you experiencing issues with your compressors? The wells are typically rotated every three months, but have you ever wondered why? What exactly is the purpose of injecting glycol into the well? What role does the well play, and what does it contain? Are there additional factors at play that may be beyond the scope of the maintenance team?
Gas wells located in the ocean require glycol injection for dehydrating incoming gas before it reaches the plant inlet, specifically in slug catchers. The wells are operated one at a time to ensure they are depleted evenly. This process is crucial for optimizing production efficiency in offshore gas extraction. We hope this information is helpful!
Are you experiencing issues with your compressors? If so, we can help resolve any problems you may be having.
Why are there no issues with the compressors?
In Brighton, it is common practice to swap wells every three months, leaving two pumps idle at all times. It is important to ensure the glycol pumps have proper lubrication when not in use for extended periods. Consult the vendor's manual for guidance on maintaining idle pumps. Consider incorporating a weekly no-load run in the pump startup procedure to prevent damage to the wells. Reservoirs must be treated carefully to avoid costly mistakes. The decision to rotate wells every 3 months is likely part of a reservoir maintenance strategy. Trust the experts' recommendations and focus on pump maintenance. While reciprocating pumps should be lubricated at start, the duty/standby schedule is less critical. If feasible, consider connecting all pumps to a common manifold for more flexibility, but proceed cautiously due to potential risks and costs. Opting for a 50:50 run schedule is suitable for soft packed reciprocating pumps.
Hello Vee, I wanted to bring to your attention that the pumps in question are reciprocating plunger models with an operating pressure range of 150 to 200 barg. These pumps are equipped with glands and an oil dripper system. The reason for the wells swapping over at regular intervals is part of their maintenance strategy, but I am concerned about the extended periods during which two pumps remain idle. Fortunately, there is no need for any modifications, additional costs, or downtime to connect these pumps to a common manifold, as their physical configuration aligns with your previous description. However, to optimize the efficiency of all pumps, it is important to note that the discharge valves of pairs of pumps should be opened to their respective wells. For example, pumps P1 and P2 should be open to well W1, while pumps P3 and P4 are open to well W2. If we wish to operate all pumps simultaneously, regardless of which well is online, we need to carefully coordinate their operation. One potential solution could be a rotating schedule, where each pump takes over the duty of servicing a specific well for a set period of time. For instance, P1 could be online for weeks 1 and 2, P2 for weeks 3 and 4, P3 for weeks 5 and 6, and so on. Your input and advice on this matter would be greatly appreciated. Thank you.
In Brighton, if all four pumps are connected to a common manifold, it is recommended to keep all discharge valves open at all times for optimal system reliability. If two pumps are required to meet the demand from each well, consider running pumps P1 and P2 for two weeks, followed by pumps P3 and P4 for another two weeks in a repeating cycle. However, if one pump can supply 100% of the flow to a well, you only need two pumps to run alternately. In this scenario, remove and service two pumps to save on maintenance costs and declutter the site and Asset Register. Regardless of the setup, the pumps will supply water to whichever well is operational.
When connecting pumps to a common manifold, there is no need for modification, cost, or downtime involved due to the physical configuration. The operating pressure ranges from 150 to 200 barg. In considering pumps P1 & P2, it is important to understand why having four pumps on a slab with a shared suction and discharge header (a pump station) is necessary. Can a single pump suffice in this setup? Are the pumps connected in series or parallel, and is there a booster pump? Are all the pumps identical, including their relief valve settings and flow control? How far are the wells from the pumps, and what led to this specific configuration? It is worth investigating the history of the wells, pumps, and company to understand the reasoning behind this setup. The design was engineered and approved by management, indicating that there are important factors beyond just the components involved.
Inquiring if a single pump can efficiently manage operations, determining if the pumps are operating in series or parallel, and checking for the presence of a booster pump are crucial considerations. Additionally, assessing the uniformity of the pumps, relief valve settings, and flow control mechanisms is essential. It is recommended to evaluate the distance between the wells and the pumps, as well as the feasibility of mothballing unnecessary equipment. This engineering oversight highlights the need for streamlining operations by possibly reducing the number of pumps from four to two. An efficient and cost-effective solution must be swiftly implemented to avoid unnecessary complications.
In Brighton, it is recommended to physically disconnect the piping from the manifold, remove the motor and gear box, and store the pumps, motors, and gear boxes. Update the asset register by removing the pump tag numbers and deleting all preventive maintenance tasks in the CMMS for these pumps. It is also advised to alternate the operation of the remaining two pumps every other week to ensure efficiency. These actions will help minimize idle pumps, decrease maintenance expenses and labor, enhance reliability, and maintain spare capacity to meet operational needs. Additionally, storing the motors and gear boxes in the store will be beneficial for future projects.
Thank you, Vee. Believe me, my colleagues would be startled if I proposed this idea to them and may be hesitant to take action. Nevertheless, I am confident that implementing this suggestion on-site will yield more positive results and allow me to drive it forward. I apologize for any delays in the process!
In Brighton, a common obstacle has arisen: resistance to change stems from a mental barrier. People are often hesitant to change, even when provided with multiple backups in case of failure. It is crucial to consider the costs involved in maintaining equipment, such as spare parts usage per year, manhours for preventative and corrective maintenance, and labor costs for monitoring equipment performance. It's essential to emphasize the financial implications of every hour spent on redundant equipment and redirecting those resources to more critical areas. Additionally, factoring in supervisor, planner, and stores hours will provide a comprehensive view of the overall costs. Best of luck in addressing this challenge.
Dear Steve, I will be recommending this to them shortly and look forward to their response. Vee, the pumps are equipped with J seal sets, lantern rings, and bushings. This answers your query regarding the type of pump packings used. Best regards.
Brighton, looking for ways to improve pump reliability, availability, and costs? Here's a strategy to consider: Take two pumps offline and store them on-site, preserving only the necessary preventive maintenance in the CMMS. This will enable a quick recommissioning if needed, although it's unlikely to occur. Running the remaining pumps biweekly can lead to noticeable improvements within six months. Collect data before, during, and after to demonstrate success. After a year, consider removing one pump set from the site and asset register, followed by another set later on. By effectively communicating your progress through various channels, you can pave the way for addressing your next goal effectively.
Hey vee, I appreciate your input and will definitely work on it. Can you provide your insights on the following queries? 1- During a discussion on Duty/Standby, I mentioned running the duty pump for 7 weeks followed by one week off, as per your suggestion. Someone asked why not run it for 1 day instead of 1 week. Do you have any thoughts on this? 2- Our reciprocating plunger pumps are equipped with hard j seals, oil drippers, and lantern rings for lubrication. They also have pulsation dampers. I couldn't get a clear answer from the vendor regarding duty/standby durations. What is your recommendation for these pumps? 3- If we follow a 2 months on/1 week off schedule for a pump with a mechanical seal, will this cause issues for the standby pump's shaft? How should we address this potential problem? 4- What is the best way to test a pump under no load conditions? If these questions seem elementary, I apologize in advance. PS. Have you distributed the article on duty/standby equipment?
In my responses, I will refer to your inquiries by the numbering you provided, Brighton. 1. The duty/standby cycle involves running for 7 to 8 weeks followed by a downtime of 8 to 24 hours. The 7-week on and 1-week off schedule is used when strict duty/standby cannot be maintained due to operational constraints. While not ideal, this setup is deemed acceptable. If possible, opt for a 7-week on, 1-day off routine. 2. I am not familiar with j seal construction. Could you share a sketch for reference? 3. In most cases, it is not necessary; however, if the shaft is slender and the pump has multiple stages with widely spaced bearings, the shaft may experience sagging and deformation. In such rare instances, manually rotating the shaft by 270 degrees weekly may be required. 4. When the discharge valve is closed, the pump operates on no load. It is recommended not to run the pump in this state for more than 10 to 15 minutes. Why would one want to test the pump under no load conditions? Your queries are valid, so no need to worry!
Thank you so much, Vee! I will be sharing a new sketch later this week. Appreciate your support! Best regards, Brighton.
Hello Vee, I would like your advice on when to change the status of standby equipment to duty. For instance, if a duty pump is malfunctioning and repairs will take one to two months, should it be immediately switched to duty after repairs or should the standby equipment continue to fulfill the duty role? Also, have you shared your article on Duty/Standby? If so, could you please direct me to where I can find it? Thank you and best regards, B.
In Brighton, a common question is: when should the status of a standby pump be changed to duty? For instance, if a pump designated for duty is in need of repair for an extended period, should it immediately become duty after repair, or should the standby pump continue in its place? The overarching rule is that the reliable pump should remain on standby, while the faulty pump should take on the duty role. It is crucial to ensure that the standby pump can effectively take over in case of a breakdown. If Terry O'Hanlon is reading this, perhaps he can provide insight on the publication date and location of my article submitted to Uptime through Jeff S.
Thank you for your quick and insightful responses. I want to discuss the issue of two centrifugal pumps located downstream of the HP flare Knock Out Drum. These pumps are meant to transfer the liquid collected in the KOD, but they have not been used in 2 years due to lack of liquid accumulation. The maximum outlet pressure for these pumps is 5 barg. How can we maintain these pumps to ensure they start when needed? Your input on this matter is greatly appreciated. Thank you.
In Brighton, there are two centrifugal pumps located downstream of the High Pressure (HP) flare Knock Out Drum (KOD) that are responsible for transferring accumulated liquid from the KOD to another location. This issue may seem minor, but it can lead to serious ramifications if not addressed. The root cause of potential pump failure is not the pumps themselves, but rather the presence of rust and scale from the KOD and suction piping. These contaminants can easily enter the pump and cause it to seize by getting stuck between the wear rings. As a common-cause failure, both pumps may fail one after the other, especially in scenarios where the KOD suddenly becomes filled with liquid. While there is no quick fix for this issue, regular cleaning of the pump suction strainers can help prevent such failures. Running one pump for a short period to clear out any debris trapped in the strainer is a simple yet effective maintenance practice. I have encountered a few incidents that could have turned disastrous due to neglecting this issue. It is crucial not to overlook this issue, as it has the potential to cause significant problems in the system.
To prevent false brinelling in bearings, it's important to follow proper maintenance schedules. Typically, a 60-40 ratio is recommended for lead and lag pumps, while a 50-30-20 ratio is advised for three pumps. Avoid letting pumps sit on stand-by for extended periods as this can lead to bearing failure. I have witnessed new equipment experiencing bearing issues after being on stand-by for a year. It's crucial to monitor pump hours and lubricate as needed to ensure optimal performance.
Hello Vee, I want to highlight that the liquid level in the drum is at a minimum, which is causing me concern. I am worried that starting the pumps in this condition may result in them getting damaged, or worse, already being damaged. This is because the pump may end up sucking gas instead of liquid from the drum, leading to issues like cavitation. To prevent corrosion of the bearings and potential pump seizure, I plan to clean the suction strainer and ensure the oiler and bearing chamber are filled with oil. However, I am unsure of the best way to start the pumps without sufficient liquid upstream. I would greatly appreciate your feedback on this matter. Thank you. Regards, B
Hello Sam, I agree with your thoughts. It is essential to develop a strategy based on the type of pumps being used on site. If the pumps are equipped with mechanical seals, it is advisable to operate them at 90% Duty - 10% Standby or higher. On the other hand, for pumps with soft gland or packings, a 50%-50% ratio is recommended. Personally, I prefer using only 2 pumps instead of 3, allowing me to keep the third one as a spare for the other two. Vee/Steve, I would love to hear your thoughts on this matter. Thank you and best regards, B
In Brighton, the preference is to use 2 pumps instead of 3. This decision involves mothballing the third pump and using its components as spares for the remaining two. The mention of 3 pumps is not clear, as previous discussions involved 4 glycol recips and 2 KOD drain centrifugal pumps. If there are unnecessary pumps on site, it is advisable to remove the extra one from the Asset Register, delete its PMs, and save on costs and manpower. This proactive approach can help streamline operations and optimize resources effectively.
Apologies for any confusion, Vee. I posted a response to Sam's thread, which is different from the discussion we had earlier about the 4 glycol pumps and 2 downstream pumps of KOD. In my initial post, I requested further clarification as I believe running just one pump may not be a practical solution in this scenario. Thank you for your assistance.
In Brighton, there seems to be a misunderstanding about the method of running one pump in a specific case. Could you please provide more details or ask the question again, specifying whether it relates to 3 pumps, 4 glycol pumps, or 2 KOD pumps? I have discussed several methods in previous responses and would like to clarify the specific query you are referring to.
Hello Vee, Apologies for the delay in my response, I was traveling abroad. Regarding the issue of the two pumps downstream of the Flare K.O.D that have not been operational for nearly two years, you mentioned starting one pump to clear out the debris in the strainer as a solution. I'm curious if it is feasible to start a pump in the absence of any liquid upstream. Also, I recall you mentioning an article on duty-standby equipment. Can you confirm if it has been published and provide details on its location on the website? Thank you.
In the October 2006 edition, Brighton asked me to review a website regarding the issue of pumps downstream of the Flare K.O.D not starting for almost two years. The suggested solution was to start one pump to draw in debris using a temporary filter cloth in the strainer. However, is it possible to start a pump when there is no liquid upstream? Unfortunately, a pump cannot be started if the vessel is empty. But, could you arrange for it to be filled for a brief trial period? The pump just needs a quick kickstart for 20-30 seconds. Be sure to remove the temporary filter cloth after the run to catch the debris. Running pumps after a long period of inactivity poses risks like not starting, not taking load, or seizing due to rust and scales in the pump housing. If safe, draining the KOD can help determine the liquid's particulate content. If your hydrocarbon streams are wet and made of carbon or low alloy steels, rust and millscale may enter the pump suction.
Hello Vee, I hope you're doing well. I came across your article and found it quite fascinating. Thank you! I wanted to discuss a new topic with you: there are duty and standby pumps controlled by level bridles attached to the reboiler upstream. These pumps, each 4 KW with mechanical seals, require the level bridles to be drained twice daily. However, during this process, the duty pump shuts down temporarily before restarting when the drain is closed. This has been going on for a year now. I suggested to the Production Superintendent to install a Maintenance Override Switch (MOS) to prevent pump shutdowns during drainage. We have two options: either implement the MOS or continue with the start-stop cycle and replace the pumps if necessary, as they are relatively small. The pumps, currently 2 years old, are still functioning well. I would appreciate your perspective on this matter. Thank you. PS. On a side note, we have been following the operating philosophy you discussed in your previous threads for the past 5 weeks. So far, it has been successful.
When it comes to pump operation, having two pumps running and one as a backup is more efficient than having one pump running and two spares. This 50-50 setup can lead to equal deterioration and potential simultaneous failure, which is not ideal. Consider a 60-40 ratio for two pumps in certain situations to prevent this. It's almost guaranteed that both pumps won't fail simultaneously with a 70-30 setup. Having a balanced distribution of pump operation can help prevent unexpected failures and ensure continuous operation.
Hello Vee, it's been 6 months since we last spoke! I wanted to discuss the equipment duty-standby philosophy and whether it can be implemented, for example, three years after the plant has been commissioned. I am considering implementing this strategy for equipment on an FPSO that is 2.5 years old. Look forward to your input. Regards, Brighton
Hello Brighton, it's great to hear from you! Have you been up to anything exciting lately? The approach of duty/standby operations can be utilized for backup equipment of any age, except for those with gland-packed seals. I detailed the rationale behind this in a publication on reliability engineering.
Hello Vee, I apologize for being away and unable to check the forum. I was eager to return, and I'm glad I finally made it back. I am interested in purchasing your book with ISBN 0-8311-3178-0. Have you authored any other books? Also, could you please guide me to the paper where you discuss the exceptions that need to be taken into account for Gland-Packed Seals? Thank you very much, Brighton.
Dear Vee, I would greatly appreciate your insights on the benefits of operating three pumps (A/B/C) simultaneously. What is the most effective way to designate duty and standby roles for each pump? Additionally, can you provide guidance on the optimal method for operating these pumps in parallel? Looking forward to your response. Best regards, Brighton
Is it advisable to operate three pumps A/B/C in parallel? How do you implement a duty/standby system for them? The operation of three pumps in parallel can be optimized based on their capacities and needs. This can include running all three pumps simultaneously (3oo3), running two out of three pumps (2oo3), or running one out of three pumps (1oo3). For 1oo3, operate pump A regularly and test start pumps B and C every two months. In a 2oo3 setup, rotate running pumps A and B while testing pump C every two months. In a 3oo3 configuration, all three pumps will run continuously. It is crucial to ensure the Q-H curves of the three pumps are similar for efficient parallel operation.
Thank you, Vee, for your guidance. I am interested in purchasing your book with ISBN 0-8311-3178-0. Are there any other published works by you that I should be aware of? Additionally, could you please direct me to the paper where you discuss the important exceptions that need to be taken into consideration for Gland-Packed Seals? Thank you, Brighton.
In a previous discussion on page 3 of this forum, I detailed why pumps with gland packing require a unique approach. For further information, please refer to the link http://www.reliabilityweb.com/art04/operating_philosophy.htm. You have mentioned twice now (previously in Sept, 06) that you plan to purchase my book. Perhaps it's time to follow through. To answer your query, Industrial Press Inc. will soon release my second book titled "100 Years of Maintenance: Practical Lessons from Three Lifetimes at Process Plants" with ISBN-13: 978-0831133238. This book consists of life stories and insights from myself and my co-authors, aimed at providing practical guidance for maintenance professionals.
Hello Mr. Steven Van Els, I am interested in finding study materials and books to prepare for the CMRP Exam administered by SMRP. As a certified professional, could you please provide me with some tips on where to find these resources? Your quote indicates a misconception about running the duty pump until it fails, but the correct approach is to monitor its condition regularly to determine when intervention is necessary based on experience. It is important to establish warning and fault limits for equipment. Additionally, it is recommended to test the standby unit periodically under normal working conditions to ensure its reliability. By implementing a schedule of 12 weeks on and 3 weeks off for the main pump, and vice versa for the backup pump, we can continuously assess the condition of both pumps. This proactive approach helps prevent premature failures and ensures that both pumps are operational when needed. Remember, it is crucial to maintain and evaluate both pumps regularly to avoid unexpected breakdowns.
Hey there, buddy! If you're looking for a valuable resource to help you prepare for your upcoming SMRP exams, then look no further than the suggested reading list on the SMRP website. Instead of diving into all the books right away, consider prioritizing based on your available time and budget. While these books can provide a comprehensive overview of exam content, it's important to remember that simply reading them won't guarantee exam success. The key lies in applying the principles learned in real-world scenarios. Check out reputable sources like Amazon, Maintenanceresources.com, Industrial Press, your local university library, and your plant library's hidden gems in the "heavy stuff" section. Additionally, staying informed by reading maintenance/engineering/process magazines and actively engaging in discussions on forums can further enrich your understanding. By incorporating these resources into your study routine, you'll be better equipped to tackle the exams with confidence.
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Answer: Answer: For reciprocating compressors with soft gland packings, a weekly switchover may be necessary for proper lubrication. Centrifugal or screw compressors, or reciprocating compressors with mechanical seals, should be operated on a duty/standby basis similar to pumps.
Answer: Answer: Thermography can be utilized to detect issues such as hot bearings, damaged insulation, or faulty steam traps in equipment, providing extensive applications for improving equipment performance.
Answer: Answer: There should be no conflict between a plant shutdown followed by three years of operation and the duty-standby approach for pump operation. Thorough research through various sources is recommended before implementing new strategies to understand their rationale effectively.
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