GASKET FAILURE.
Gaskets are critical sealing components used to prevent leakage between two mating surfaces. However, they can fail due to various reasons. Below are common failure modes of gaskets, categorized by cause:
1. Mechanical Failure
a. Over-compression: Gasket crushed beyond its design limit, leading to loss of elasticity and sealing ability.
b. Under-compression: Insufficient bolt load causes poor sealing and leakage.
x. Improper bolt tightening: Uneven torque can create stress concentrations and leakage paths.
2. Thermal Failure
a. Thermal cycling: Repeated heating and cooling cause expansion and contraction, degrading the gasket material.
b. Overheating: Exposure to temperatures beyond the gasket’s rating leads to hardening, cracking, or burning.
3. Chemical Attack
a. Incompatible media: Fluids or gases chemically degrade the gasket, causing swelling, embrittlement, or dissolution.
b. Oxidation: Long-term exposure to oxygen at high temperatures weakens certain gasket materials.
4. Creep and Relaxation
a. Creep: Gasket slowly deforms under constant load at high temperature, reducing sealing force.
b. Stress relaxation: Loss of bolt load over time reduces compression on the gasket, leading to leaks.
5. Improper Gasket Selection or Installation
a. Wrong material: Selecting a gasket not suitable for pressure, temperature, or chemical environment.
b. Poor surface finish: Flange surface too rough or too smooth affects sealing.
c. Misalignment: Incorrect gasket placement or flange misalignment causes uneven stress distribution.
6. Fluid Pressure-Related Failures
a. Blowout: Sudden rupture of gasket under pressure due to weak design or incorrect installation.
b. Extrusion: Gasket material pushed out of joint under high pressure, often due to soft material or high gap.
7. Environmental or Aging Effects
a. Material degradation: Natural aging, UV exposure, or moisture can weaken gasket properties over time.
Summary:
1. Gasket failures often result from incorrect compression due to improper bolt torque, leading to leaks.
2. Thermal cycling and chemical exposure can degrade the gasket material over time.
3. Creep and relaxation reduce sealing force under sustained load and heat.
4. Misalignment during installation causes uneven sealing, while sudden pressure spikes may lead to gasket blowout.
5. Proper selection and installation are key to preventing these issues.
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