Flange Gaskets

What Is a Flange Gasket?

A flange gasket is a precision sealing element placed between two flanges to create a leak-proof joint when the flanges are bolted together. It compensates for surface imperfections and fills gaps that could otherwise allow fluids or gases to escape.

Flange gaskets are essential in systems carrying liquids, vapours, or gases under pressure. They are available in various styles – such as ring gaskets (sealing only the flange face) and full-face gaskets (covering bolt holes as well).

The choice of gasket material depends on factors like:

• Temperature range.
• Pressure rating.
• Type of media (water, steam, oil, gas, chemicals).
• Flange surface finish and bolt load.

5. Corrosion Barrier

Certain gaskets isolate metal surfaces from one another, helping prevent galvanic or chemical corrosion in corrosive environments.

6. Easy Installation and Maintenance

Most flange gaskets are easy to install and replace, minimising maintenance time and ensuring long-term reliability.

7. Cost Efficiency

Flange gaskets reduce the likelihood of leaks, system failures, or shutdowns, saving time and money on both emergency repairs and production losses.

Common Flange Gasket Materials in Manufacturing

Selecting the right gasket material depends on the media being handled, system pressure, temperature, and regulatory requirements.

1. Rubber (NBR, EPDM, Neoprene, FKM)

Used for general water, air, and low-pressure oil sealing. Cost-effective and easy to handle.

2. PTFE (Teflon)

Inert and hygienic, ideal for chemical and pharmaceutical systems. Resists acids, solvents, and high temperatures.

3. Graphite

Used for steam, hot oils, and high-temperature, high-pressure environments. Maintains sealing integrity under thermal cycling.

4. Compressed Non-Asbestos Fibre (CNAF)

Suitable for oils, water, steam, and mild chemicals. Versatile and asbestos-free.

5. Metallic and Semi-Metallic Gaskets

Spiral wound, ring-type joints, and kammprofile gaskets are used for extreme pressures and thermal conditions.

6. Fibre (Cellulose, Aramid)

Used in lower-pressure applications. Easy to cut and install; ideal for pump and valve gaskets or older equipment.

Common issues solved by Flange Gaskets

Flange Gaskets prevent many costly and dangerous system failures. When correctly selected and installed, they solve several recurring problems in industrial systems:

• Incorrect Material Selection
  Using the wrong material can cause chemical degradation or thermal breakdown. Always match gasket composition to media and operating conditions.
• Installation Errors
  Over- or under-tightening bolts can cause gasket damage. Flange faces must be properly cleaned and aligned.
• Compatibility with Flange Type
  Different flange types require specific gasket styles. For example, metal gaskets are only suitable for high-quality, smooth flange finishes.
• Gasket Creep and Relaxation
  Heat and pressure can cause some gasket materials to relax over time. This can be mitigated with high-performance materials like graphite or reinforced composites.
• Stocking Challenges
  Having too many sizes and materials in stock increases overhead. A versatile gasket programme simplifies inventory and ensures readiness.
• Maintenance Downtime
  Choosing higher-quality gaskets may increase service life and reduce the need for frequent changeouts or unplanned shutdowns.