Feb 14, 2025
A compression gasket is a critical sealing component that ensures a secure bond between joined surfaces. The effectiveness of its seal depends on multiple factors, including the percentage of compression applied to the gasket material. Compression gaskets are subjected to various stresses, including mechanical loads, vibrations, and temperature fluctuations. To maintain an effective seal, the gasket material must be able to expand and contract while consistently returning to its original shape.
Durlon® 8500 and Durlon® 8600 are high-performance compressed non-asbestos (CNA) gaskets designed for demanding applications across industries such as food and beverage processing, chemical processing, mining, OEM services, water and wastewater treatment, primary metals, and rail tank cars.
This article explores the significance of gasket compression, optimal compression percentages, factors affecting gasket performance, and the concept of compression set.
Why Does Gasket Compression Matter?
Gasket compression plays a fundamental role in ensuring a leak-proof seal between mating surfaces. When a gasket is installed, it deforms to fill microscopic surface irregularities, preventing leaks and maintaining pressure stability. Additionally, the gasket must adapt to changes caused by vibrations and temperature variations.
Proper gasket compression is essential for several reasons:
- Leak Prevention:
Insufficient compression may result in fluid or gas leaks, compromising system integrity. - Structural Integrity:
Over-compression can damage the gasket, causing premature failure. - Regulatory Compliance:
Industries such as food and beverage manufacturing require gaskets to meet strict regulatory standards, including material compatibility and resistance to aggressive cleaning processes.
Optimal Gasket Compression Percentage
Each gasket material has an ideal compression range that ensures a complete and effective seal. The recommended compression percentage varies based on the material, application, and design specifications. Generally, gasket compression falls within the 25-50% range.
- Over-compression Risks:
Excessive compression can cause material deformation, preventing the gasket from returning to its original shape. This results in sealing failure, potential leaks, or even a blowout. - Under-compression Risks:
Insufficient compression can allow fluid infiltration, increasing the risk of material degradation and compromised sealing performance.
Selecting the Right Compression Percentage
Gasket compression is measured as a percentage of its original thickness. The appropriate compression level depends on manufacturer recommendations, which provide torque specifications and installation guidelines to ensure proper sealing performance.
For example:
- Durlon® 8500 and Durlon® 8600 Gaskets:
- Compressibility: 8-16%
- Recovery: 45% (Durlon® 8600), 50% (Durlon® 8500)
- Creep Relaxation: 20%
Causes of Gasket Compression Issues
Several factors contribute to gasket compression problems, including:
- Chemical Exposure:
Harsh chemicals can degrade gasket materials, reducing their sealing effectiveness. - Extreme Temperature Variations:
Insufficient compression can allow fluid infiltration, increasing the risk of material degradation and compromised sealing performance. - Over-Torquing:
Excessive bolt torque can cause permanent deformation, resulting in compression set. - Material Relaxation:
Certain gasket materials may experience relaxation over time, diminishing their sealing properties. - Pressure Cycling:
Repeated pressure fluctuations within a system can cause mechanical fatigue, reducing gasket lifespan. This is particularly relevant in industries such as food processing, where pressure cycling is used for sterilization and product handling.
Understanding Compression Set
Compression set refers to the permanent deformation of a gasket after being compressed and subsequently released. When a gasket material fails to return to its original thickness, its ability to maintain an effective seal is compromised. Compression set is expressed as a percentage, with lower values indicating higher resistance to deformation.
Key factors influencing compression set include:
- Material Density and Type:
Denser materials typically exhibit lower compression set values. - Manufacturing Quality:
Higher-quality gaskets are designed to withstand prolonged compression cycles without significant deformation. - Operating Conditions:
Exposure to extreme temperatures, pressure cycling, and chemical environments can accelerate compression set.
Enhancing Gasket Performance
Gaskets with low compression set values offer superior reliability, minimizing maintenance requirements and reducing downtime. Selecting the right gasket material and following manufacturer-recommended installation procedures are essential for maximizing performance and longevity.
For more information on selecting the ideal compression gasket for your application, contact our experts today.