mechanical seal failure analysis in stock

When a mechanical seal fails in one of your operation’s vital pieces of equipment, figuring out the cause of the failure is often even more important than procuring a replacement seal. After all, if there is an underlying issue causing your seals to fail, replacing the seal is only going to be a temporary fix. Unless you plan on purchasing and installing new seals on a regular basis – something that can quickly become both expensive and time-consuming – figuring out the cause of your seal failures is an essential objective.

This is where mechanical seal failure diagnostic services can prove highly valuable. By simply examining your broken seal, we at Gaddis Mechanical Seals are able to pinpoint the exact cause of its failure, enabling you to perform whatever repairs are necessary to keep the same issue from happening again in the future.

At Gaddis Mechanical Seals, we strive to make our seal failure diagnostic services as convenient as possible for our valued customers. All you have to do is send us your broken seal along with any available information regarding where the seal was located and the events leading up to its failure. From there, our expert team will perform a wide range of diagnostics to determine the exact cause behind the seal’s failure.

This includes inspecting the seal’s O-rings, face, springs, gasket, and every other component. By determining the exact component within the seal that failed and analyzing the design of the equipment that it came from, we are able to provide our customers with an accurate and detailed description of exactly what needs to be fixed in order to prevent the same issue from happening again.

Mechanical seal failures are the most common cause of pump downtime and failure, so mechanical seals and seal support systems must be very carefully designed with components and options selected according to the specific application. However, even high-quality seal support systems can fail unexpectedly for a variety of reasons. When this happens, it’s critical to conduct mechanical seal support failure analysis quickly and accurately, because every minute of downtime results in lost production.

Identifying the failure mode and root cause of a mechanical seal failure allows you to not only correct the immediate problem but prevent it from happening in the future. Thorough mechanical seal support failure analysis can help you understand the conditions under which the seal failed.

In this article, we’ll look at the three most common types of seal support failures—leaks, overheating, and seal failure—what can cause them, and how to prevent them with proactive measures.

Mechanical seals minimize leakage around rotating equipment by creating a “seal” between two very flat surfaces—one stationary and one rotating. These mechanical seal faces inevitably produce some leakage, but the leakage normally evaporates immediately and isn’t a problem. When leaks become noticeable, it’s time to perform mechanical seal support failure analysis to find out why.

When troubleshooting mechanical seal leaks, make note of any unusual noises, damage, or other symptoms accompanying the leak. Use the table below as a starting point to help you identify the cause of the leak.

Overheating indicates either friction between rotating components or excessive fluid temperatures. There are two main reasons mechanical seals overheat: inadequate cooling and excessive friction. Refer to the table below to help diagnose the problem.

As you can see, there is a lot of overlap between the causes of leaks and overheating. Many mechanical seal failure modes can be traced back to the same underlying causes, so be sure to check for leaks as well and use the leak troubleshooting table to investigate.

Excessive heat can eventually lead to heat checking. Mechanical seal heat checking can be identified by fine radial cracks in the seal face caused by excessive stress from the mechanical load and thermal expansion. These cracks may be barely visible to the naked eye, so heat checking can go unnoticed until failure occurs and it’s too late to save the seal. The risk of heat checking increases with high temperatures and high-viscosity fluids like those used in SAGD. It is more common in brittle materials like tungsten carbide.

The same underlying issues that cause leaks and overheating can eventually lead to complete seal failure. A mechanical seal failure likely began as a leak or overheated condition that went unaddressed. The same troubleshooting procedures for leaks and overheating apply, but once the seal has failed, correcting the problem becomes much more difficult. Therefore, it’s important to be proactive and check for problems like leaks and overheating before they cause major problems.

Do you still need help with mechanical seal support failure analysis, or want to learn more about how to be proactive in preventing failures? Field Advisors at Edmonton Valve & Fitting can perform an onsite or remote evaluation to determine the cause of failure and make recommendations on upgrades, component materials, tubing diameters, and instrumentation to help deter mechanical seal failures.

To find out more about how Edmonton Valve & Fitting can help with mechanical seal support failure analysis, contact usthrough our websiteor by calling 780-437-0640.

Fluid Sealing International offers Mechanical Seal Analysis (MSA) service.  As a seal is disassembled all parts are inspected to determine their condition with respect to original specifications.  It is during the MSA procedure that a failure mode can be identified and recommendations can be determined.  These may include changes required in equipment operation, suggested environmental controls for improved performance, upgrades in seal materials, or even a change in seal design.

After a complete inspection of the seal, all major parts are cleaned and replaced.  Where necessary, Fluid Sealing International can provide Mechanical Seal Repair Services to repair your seal.

Mechanical seals prevent pumps from leaking by containing the pressure of the pumping process and withstanding the friction caused by the rotating shaft. The right seals provide reliable operation, less wasted product, more cost savings, and fewer housekeeping issues. However, why do mechanical seals fail?

In many pump systems, a mechanical seal is the first component to fail. They are also the most common cause of pump downtime and account for more pump repair costs than any other part of a pump. Often, however, the seal is not to blame. Other culprits include:Bearing wear

Therefore, teams must install and maintain seals properly to prevent failures. Teams must pinpoint the root causes of each failure. But how do plant and maintenance managers isolate the root cause though?

One option is to have a seal manufacturer perform a seal failure analysis. Some seal manufacturers offer complimentary seal analysis on any seal, not just theirs.

End users simply send their mechanical seal to the manufacturer’s engineering team. If multiple seals need to be analyzed, they may come on-site to perform the root cause analysis. Most reviews canbe completedin about two weeks.

With a seal failure analysis, experts deliver a complete diagnosis of why the mechanical seal failed and what actions to take to prevent future failures. The experts who examine the seal can ensure that the ideal seal for the application has been selected. If not, they recommend alternate technologies.

After an analysis, the manufacturing ream will also help end users optimize their system conditions and achieve the best possible operation from their assets. Optimizing mechanical seal performance also improves shutdown to shutdown processes. This information, along with alternative proposals as needed, help end users prevent further failures and improve their return on investment.

Many problems with a system may be discovered by investigating a failed mechanical seal. In most instances, a seal problem is not the reason for the failure. Something else happened to cause it.

The story of what the seal experienced during operation, before it failed, can be revealed by investigating the failure. An analysis may determine or confirm:If misalignment or other mechanical problems exist in the pump system

Eliminating the problems identified by the seal failure analysis may have a huge impact on the system. Several improvements may be realized, including:Optimized operating conditions

For instance, a stationary seal face is cracked, originating from the drive pin slot. Also, sticky residue has adhered to the face. This crack means something different than a stationary seal face with a crack located at a different position and product residue that is fairly clean and not tacky.

Both cases look the same on a simple table listing all the seal damage. However, the failure cause is different. In the first example, the crack was caused by the product attempting to stick the rotary and stationary faces together. This adhesion caused increased torque on the stationary pin. This caused the stationary face to crack.

In the second example, the crack was likely caused by impact. This indicated that the seal was not installed properly. Different symptom combinations reveal multiple failure modes.

In conclusion, to determine the true reason that a seal failed, seal failure analysis is required. Without a diagnosis of the system problem, failure will continue.

Jack Ferguson is a seal reliability engineer with Sealing Equipment Products Co. Inc. (SEPCO). He is a recent graduate of Clemson University with a degree in mechanical engineering. Ferguson may be reached at jackf@sepco.com.

Failure of the mechanical shaft seal is the most common cause of pump downtime. The shaft seal is exposed to widely varying operating conditions. Sometimes operating conditions change to become quite different from the specific conditions for which the seal was intended.

85% of process mechanical seals, fail long before they are worn out. In these series we are going to examine the most common wear patterns that could lead us to critical conclusions regarding the reason of failure.

The inner face of a “back to back” double seal application is not positively locked in position. A snap ring must be installed to prevent the inboard stationary face from moving towards the rotating face when the high pressure barrier fluid pressure is lost or overcome by system pressure.

In each used mechanical seal you provide us, our team in Technoseal will implement the mechanical seal failure analysis and suggest you the best solution as far as the design, the material selection and the installation limitations are concerned.

Knowing the manufacture and model number of the mechanical seals and pumps at your plant is imperative when managing your plant.  Carolina Seals offers an Equipment Survey program in which we will collect important data about equipment such as but not limited to:  Equipment ID and service name, Type and mfg of mechanical seal, Single seal or Double seal, API piping plan, standard bore or large bore seal chambers, pump Mfg and Model #s, bearing isolators or lip seals, oil bath or grease, motor frame size, Horse power, & rpms.   With help from the plant we can determine how critical each piece of equipment is and create an Excel spreadsheet listing the collected data.  This spreadsheet will aid you in determining the following:  Troubleshooting issues with pump & sealing specialist,  Inventory of pump parts and mechanical seals, Establishing the average  Mean Time Between Failure of your equipment and Identify bad actors.

Prevention of seal failures through proper design, material selection and maintenance certainly minimizes the risk of failure. Attention to the condition of replaced seals, as well as the equipment performance over time, will result in improved process reliability, reduced operating costs and a safer work environment.

O-ring seals often fail prematurely in applications because of improper design or compound selection. This section is designed to provide the user with examples of common failure modes. By correctly identifying the failure mode, changes in the design or seal material can lead to improved seal performance.

One major factor in possible seal failure is the extreme and harsh environment in which seals are expected to perform. The sealing environment can consist of virtually anything from inert gases at room temperatures to aggressive chemicals at very high temperatures. The sealing environment may result in chemical degradation or swelling of the sealing components. Elevated temperatures may cause seal degradation, swelling or outgassing. And the pressure—or more often, the vacuum environments—can cause outgassing and weight loss.

Analysis of the seal application is crucial to the understanding of possible failure. Most seal design is performed by component suppliers and equipment manufacturers. The designs are refined as experience is gained. As quickly as process technology changes, however, the experience gained with seal design may not be relevant to the latest process technology. Vacuum applications have historically relied on high levels of compression and gland fill to reduce permeation and trapped gases. These techniques, when applied to new materials, or at higher operating temperatures, can result in premature seal failure.

Description:The seal or parts of the seal exhibit a flat surface parallel to the direction or motion. Loose particles and scrapes may be found on the seal surface.

Contributing Factors:Rough sealing surfaces. Excessive temperature. Process environment containing abrasive particles. Dynamic motion. Poor elastomer surface finish.

Description:The seal may exhibit many signs of degradation including blisters, cracks, voids or discoloration. In some cases, the degradation is observable only by measurement of physical properties.

Description:The seal exhibits blisters, pits or pocks on its surface. Absorption of gas at high pressure and the subsequent rapid decrease in pressure. The absorbed gas blisters and ruptures the elastomer surface as the pressure is rapidly removed.

Description:The seal exhibits parallel flat surfaces (corresponding to the contact areas) and may develop circumferential splits within the flattened surfaces.

Description:The seal often exhibits discoloration, as well as powdered residue on the surface and possible erosion of elastomer in the exposed areas.

Contributing Factors:Chemical reactivity of the plasma. Ion bombardment (sputtering). Electron bombardment (heating). Improper gland design. Incompatible seal material.

Description:The seal may exhibit radial cracks located on the highest temperature surfaces. In addition, certain elastomers may exhibit signs of softening—a shiny surface as a result of excessive temperatures.

Any piece of equipment which has been in operation has a story to tell. The condition of the equipment can uncover a rich set of information which reveals the way the equipment was operated, maintained, and eventually, degraded. Noticing that equipment has failed is only the beginning. Understanding how and why it failed can be more useful since it gives the user the opportunity to eliminate or mitigate the causes of failure. Unfortunately, this is not a casual exercise and requires a structured approach. Fortunately, the methods of problem solving can be demonstrated and extrapolated to a wide variety of applications. This course will introduce Root Cause Analysis (RCA), function evaluation, and mechanism identification in the context of mechanical seal failure investigations. In addition, these same techniques will be applied to monitoring opportunities for mechanical seal piping plans in operations. All of these techniques will focus on identifying true root causes and creating effective corrective actions to prevent the reoccurrences of failures.

Any piece of equipment which has been in operation has a story to tell. The condition of the equipment can uncover a rich set of information which reveals the way the equipment was operated, maintained, and eventually, degraded. Noticing that equipment has failed is only the beginning. Understanding how and why it failed can be more useful since it gives the user the opportunity to eliminate or mitigate the causes of failure. Unfortunately, this is not a casual exercise and requires a structured approach. Fortunately, the methods of problem solving can be demonstrated and extrapolated to a wide variety of applications. This course will introduce Root Cause Analysis (RCA), function evaluation, and mechanism identification in the context of mechanical seal failure investigations. In addition, these same techniques will be applied to monitoring opportunities for mechanical seal piping plans in operations. All of these techniques will focus on identifying true root causes and creating effective corrective actions to prevent the reoccurrences of failures.

Years ago, most pump shafts were sealed using rings of soft packing, compressed by a packing gland, but this type of shaft seal required a fair amount of leakage just to lubricate the packing and keep it cool.

Then came the development of the mechanical seal, which accomplishes the job of restraining product leakage around the pump shaft with two very flat surfaces (one stationary and one rotating). Even though these mechanical seal faces also require some leakage across its faces, this leakage normally evaporates and is not noticeable.

However, because of the delicate components used for this new sealing method, mechanical seal failures are the greatest cause of pump down time. To avoid this, it"s essential to apply the right seal for the desired and appropriate function.

A seal can be exposed to a wide variety of operating conditions—sometimes very different from conditions the seal was intended for—which can cause issues down the line. However, even if your seal is the right one for the job, there can be times when it fails faster than anticipated.

Allowing your pump to run dry can be very damaging to a mechanical seal. Under the right conditions, mechanical seals can experience thermal shock and shatter within 30 seconds or less.

VIBRATIONPump vibration is caused by pump imbalance, improper alignment, operating the pump too far to the right or left of the BEP (Best Efficiency Point) on theperformance curve, etc. Vibration hurts your equipment and can result in damaged seals and shortened seal life.

When it comes to pumps, hammers are not friends! Mechanical seal faces can be very fragile. Pounding couplings onto the shaft will damage the mechanical seal.

Lack of knowledge and information accounts for the majority of mechani­cal seal installation errors. Consider normal operating conditions, the potential for off-design excursions, and non-process activities, such as cleaning, steaming, acid and caustic flushes. The picture to the right is an example of poor material choice for an abrasive liquid.

Tom Borrino, Regional Engineer for John Crane, recommends that if you’re interested in reducing seal failures, take a look at all phases of equipment application – how is the sealed equipment specified, installation practices, all the way up to operations. Seals are very repeatable, so if you continue operating the same seal, expect to see the same rate of failure in the same manner. He further recommends thinking about the seal in terms of its total lifetime costs – not so much by its initial cost. Start a reliability program that defines the cost of failure and justify it by increasing the seal’s mean time between failures.

Look to your local seal supplier for help with seal selection, best-operating practices, and seal flush plan recommendations. If you have specific questions, ask us about them! We gladly provide mechanical seal assistance to businesses in Wisconsin and Upper Michigan.

A company specializing in temperature-controlled warehousing and logistics for the food industry recognized an issue concerning a failed mechanical seal on a Goulds 3196 ammonia pump. Being that ammonia pumps are critical to maintaining temperatures at a cold storage facility, identifying the problem and appropriate solution was dire. In conjunction with the facility"s Maintenance department, the engineering and service teams at Crane Engineering worked tirelessly to troubleshoot and identify the right solution.

This cold storage facility has two primary pumps used to maintain temperature throughout the facility. One of these pumps experienced catastrophic seal failure less than one year after it was replaced by the customer. To make things worse, the other critical pump wasn’t doing much better as it slowly leaked as well. The customer was in a tough situation as it was now June and the weather was really starting to heat up – making it even more difficult to maintain the cold temperatures. Time was running out.

Instead of simply installing a new seal, the team at Crane Engineering made the decision to troubleshoot and determine why the customer-installed seal failed in under one year. Oftentimes there is an underlying cause for seal failures, especially when they happen within a short period of time. It was determined that seal selection was not the issue, this style of seal is commonly used across the cold storage industry and is widely accepted due to its reliability.

The pump was disassembled by Crane Engineering"s service team in Kimberly, Wisconsin. The condition of critical parts was assessed to determine if replacing the seal would fix the problem. With a number of components showing significant wear, it was determined that replacing the seal would only be a temporary solution, as the worn components directly impact the overall reliability of the seal.

A Crane Engineering Account Manager also noticed the seal’s piping plan wasn’t ideal as it sloped in the wrong direction with tight 90 degree elbows instead of gentle slopes. A proper pipe installation method was discussed and necessary changes were made to ensure adequate lubrication.

The pump repair and installation took a total of two days. A number of causes for the shortened seal life were found, and necessary components on the pump were either repaired or replaced. Since then, the pump has operated flawlessly, and the facility came out with a greater depth of knowledge on the subject. Root cause analysis of the failed mechanical seal helped to ensure maintenance personnel could extend the life of their pumps minimizing costs associated with repeated mechanical seal failure.

According to its own analysis, some 98% of mechanical seals fail prematurely before they have reached their optimum design life-time expectancy. The Flowserve Seal Failure Analysis App is a web-based tool designed to visually identify and prevent future mechanical seal failures.    Accessible via desktop, tablet and mobile devices, this reference tool is a resource for reliability engineers and maintenance staff, tasked with troubleshooting and preventative maintenance. While mechanical seal failures are the number one cause of pump and mixer down-time, this area represents a great opportunity to reduce whole life costs on site across all pump systems.