SEALS & GASKETS FAILURE ANALYSIS OVERVIEW The following presentation will provide you with a basic understanding of the most common causes of seal failure. Please call for assistance regarding specific applications or issues.
Dec 18, 2015
SEALS & GASKETS
FAILURE ANALYSIS OVERVIEW
The following presentation will provide you with a basic understanding of the most common causes of seal failure. Please call for assistance regarding specific applications or issues.
Failure Analysis
Solution• Utilize a lubricant with
higher temperature capability.
Carbonized LubricantProblem• Carbonized lubricant
can result when the lubricant temperature limits have been exceeded.
• Degraded lubricant will deposit around the main sealing interface, hindering sealing capability.
Failure Analysis
Solution• Verify whether the required shaft lead is present. • If shaft lead is insufficient, correct it, or use a
recommended seal design to aid installation.
Fractured ElementProblem
• Fractured elements can result from installation damage.
• The element hinge is rolled over, causing element fracture or splits.
Failure Analysis
Solution• Determine if the delamination is a result of improper installation; • If so, modify installation technique to eliminate future
occurrence.
DelaminationProblem
• Delamination can develop as a result of air trapped in the element.
• Material separation will reduce sealing capability.
Failure Analysis
Solution• Decrease internal pressure,
allowing adequate lubrication to the primary sealing lip.
Lack of LubricationProblem• Lack of lubrication
to the sealing surface can be a result of excessive internal pressure or insufficient lubrication.
• Surface cracks or irregular wear patterns can develop.
Excessive Wear Pattern
Problem• An excessive wear
pattern can result from internal pressure, high misalignment / runout or an oversized shaft. A wide wear pattern will result in ineffective sealing.
Solution• Determine maximum
operating parameters, and use seal design recommended for the application.
Rolled Sealing Lip
Problem:• A rolled sealing lip is
caused by improper installation or inadequate shaft lead. This could result in element fracture, and immediate leakage.
Solution:• Verify whether the
required shaft lead is present. If shaft lead is insufficient, correct it, or use a recommended seal design to aid installation.
Extended Service
Problem• Extended service is
typically a result of changing product requirements or modified maintenance planning. Increased lip wear will lower sealing capability.
Solution• Upgrade the seal design
and element material for extended service capability.
Spring DelaminationProblem• Excessive deflection,
elevated temperature or improper preparation can separate the spring and sealing element, causing leakage.
Solution• Upgrade to seal with
additional shaft-to-bore capability. If temperature is elevated, use alternate sealing material to meet application requirements.
Fluid Degradation
Problem• Fluid degradation is a
result of incompatibility between lubricant or coolant and the sealing element material. Excessive swelling or element distortion will develop.
Solution• Verify application coolant
and lubricants, then utilize recommended seal design and materials.
Thermal DegradationProblem• Thermal degradation
typically results from increased temperature at the sealing interface. Breaks or cracks that develop on the primary sealing lip may cause leakage or contamination.
Solution• Upgrade the sealing
element material to satisfy the application temperature requirements.
Fractured Carrier SpringProblem:• Fractured carrier springs
typically result from improper installation, or undue distortion from excessive weight. Fracture or distortion of the carrier spring results in ineffective sealing.
Solution:• Improve installation
technique, or utilize installation tools to eliminate future occurrence.