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.