What Causes Mechanical Seals to Fail?

Posted on: Tuesday, May 10, 2022

Posted by: Hisco Engineering Department

Mechanical seals are a vital part of any pump system. They help prevent leaks, contain pressure, and withstand the friction caused by the shaft's rotations. When mechanical seals are working correctly, they ensure a pump's reliability and operability. However, these seals are usually the first pump component to fail.

Mechanical seals may fail due to issues with the pump, the seals themselves or due to external environmental and operational pressures. Some common causes of seal failures include excessive pressure, worn shafts or bearings, dirty or contaminated fluid, improper installation, and inadequate lubrication.

Identifying the cause of the failure is crucial for preventing future issues. Here are a few ways to help you and your team pinpoint problems and understand the importance of seal failure analysis.

What Causes Mechanical Seal Failure?

Most seal failures can be attributed to one of three main causes: poor installation, poor materials, or poor seal design. To determine the cause of failure, it is crucial to perform a seal evaluation and look for evidence of distress or damage. For example, if the seal faces are scored or scratched, this may indicate that the seal was installed incorrectly. If the seal material is discolored or hardened, this may mean that the wrong material was used for the application. Finally, if the seal geometry is incorrect or mismatched, this may indicate a problem with the seal design.

Taking the time to examine a damaged mechanical seal can provide valuable insights into what went wrong and determine how failures might be prevented in the future. When examining a failed seal, it's important to look at the following:

  • The orientation of the seal
  • The type of damage
  • The location of the damage
  • The amount of wear on the seal

Once you have collected all of this information, it can be used to help your team determine the root cause of the failure.

What is a Mechanical Seal Failure Analysis?

Another option is to have a Mechanical Seal Failure Analysis (MSFA). This is performed by the manufacturer or a 3rd party expert to determine the root cause of a seal failure. This expert report can provide information to help prevent future failures and identify additional or potential problems in the pump system.

The MSFA process begins with the expert reviewing the broken seal or in some cases by coming on-site. They will then begin to document the circumstances surrounding the failure. This includes taking photos of the failed seal and if necessary, collecting any failed parts. The next step is for the examiner to perform an "autopsy" on the failed seal to identify any abnormalities that may have contributed to the failure. Once all this information is compiled into a report it can then be used to make recommendations for preventing future component failures.

Why Is a Mechanical Seal Failure Analysis Recommended?

A failed seal analysis is recommended in the event of a failure because it helps identify the root cause of the issue which may not always be readily apparent. The combination of on-site observations, interviews with maintenance staff, and a review of maintenance records by an independent evaluator will allow for a non-bias explanation and solution to the issue. After the data is collected, the evaluator will look for trends and potential factors that lead to the failure.

Seal failure analysis is essential for preventing future problems because:

  • It provides an unbiased view of the problem
  • All potential causes are considered
  • Solutions are tailored to your system’s specific needs

How we can help

By having a seal failure analysis performed by an expert, your team can have peace of mind knowing that the source of the problem has been identified and can be addressed or repaired. Helping you prevent costly downtime, production losses, and future failures down the road.

Mechanical seal failure can be caused by a variety of factors, and the root cause of the failure can be difficult to determine without a mechanical seal failure analysis. Having an expert perform a mechanical seal failure analysis can help identify the problem and suggest steps that can be taken to prevent similar failures in the future. If you are experiencing seal issues, don’t hesitate to contact us. We have the experience and the expertise necessary to help you get your equipment back up and running!