What Are Non-Asbestos Gaskets?

Non-asbestos gaskets seal flange connections in piping systems using synthetic or fiber-based materials that do not contain asbestos. In oil and gas service,workers typically use green or blue sheet material and then cut it into gasket shapes to match specific flange sizes and pressure ratings.

Material Composition

Manufacturers build non-asbestos gasket sheets from aramid fibers, synthetic fibers, elastomers (such as NBR or SBR), and chemical fillers. As a result,these materials replace asbestos while still providing strength, flexibility,and chemical resistance.

How They Work

First, workers place the gasket between two flange faces. Next, they tighten
the bolts in a proper sequence. Consequently, the gasket compresses and conforms to small surface imperfections. Finally, this compression creates a tight seal that prevents fluid or gas leakage.

Typical Applications

• Oil and gas production and processing facilities
• Refineries and petrochemical plants
• Water, steam, and utility piping systems
• General industrial flange connections
• Pumps, valves, and heat exchangers

Common Characteristics (Green/Blue Sheet Material)

• To begin with, suppliers deliver the material in flat sheets that workers cut into gaskets
• In addition, manufacturers color-code sheets (often green or blue) for quick identification
• Moreover, the material remains flexible, which makes field installation easier
• Furthermore, different grades support different pressure, temperature, and chemical conditions

Advantages

• Most importantly, engineers use it as a safer alternative to asbestos materials
• In addition, it performs well under moderate pressure and temperature conditions
• Similarly, contractors choose it because it costs less than many specialty gasket types
• Finally, workers can easily cut and fit it on-site for a wide range of flange sizes

Limitations

• However, it performs less effectively in extreme temperature or high-pressure service
• In some cases, certain chemicals can degrade the material over time
• As a result, technicians may need to re-tighten bolts after thermal cycling in certain systems

Summary

In summary, non-asbestos gaskets replace older asbestos sheet gaskets in flange systems. In oil and gas applications, technicians cut green or blue fiber-reinforced sheets into gasket shapes and install them between flanges. Therefore, they create a reliable, cost-effective sealing solution for a wide range of service conditions.