Ultimate Gasket User Guide

Understanding Viton (FKM), EPDM, Buna-N, and PTFE Gaskets for Processing Systems

1. Overview: Why Gasket Selection Matters

Gaskets form a critical seal between tri-clamp fittings, flanges, and other connections in recovery fluid systems. The correct gasket material ensures compatibility with your process media, operating temperature, and pressure requirements — helping prevent leaks, degradation, and contamination.

This guide compares four of the most commonly used gasket materials:

Viton (FKM / Fluoroelastomer)
EPDM (Ethylene Propylene Diene Monomer)
Buna-N (Nitrile Rubber / NBR)
PTFE (Polytetrafluoroethylene / Teflon®)

2. Gasket Material Comparison

Viton (FKM / Fluoroelastomer)

Best for: High-temperature systems and aggressive chemical resistance

Temperature Range: -20°C to +205°C (intermittent use up to 230°C)

Chemical Resistance: Excellent resistance to oils, acids, fuels, and many aggressive fluids

Common Uses: Fluid systems, high-temp equipment & high-purity environments

Not Recommended For: Steam, polar fluids like ketones or amines

Strengths:

Excellent compression set resistance
Long service life under heat and pressure
Ideal for high-performance processing environments

EPDM (Ethylene Propylene Diene Monomer)

Best for: Steam, water-based fluids, and polar fluids

Temperature Range: -50°C to +150°C

Chemical Resistance: Excellent with steam, water, glycol, alcohols, and oxygenated compounds

Common Uses: Clean-in-place (CIP) systems, water lines, hygienic processing

Not Recommended For: Petroleum-based fluids or hydrocarbons

Strengths:

Excellent weather and ozone resistance
Steam-compatible
Cost-effective and widely used in food/pharma

Buna-N (Nitrile Rubber / NBR)

Best for: Oils, greases, and general-purpose sealing

Temperature Range: -40°C to +120°C

Chemical Resistance: Good with oils, greases, and hydraulic fluids

Common Uses: Pumps, compressors, fluid manifolds, basic process systems

Not Recommended For: Strong acids, ozone, or polar fluids

Strengths:

Affordable and flexible
Excellent tear and abrasion resistance
Good sealing for oils and non-polar fluids

PTFE (Polytetrafluoroethylene / Teflon®)

Best for: Universal chemical resistance and ultra-high purity systems

Temperature Range: -200°C to +260°C

Chemical Resistance: Near-total resistance to aggressive acids, bases, and cleaning agents

Common Uses: Ultra-clean fluid processing, acid lines, high-purity chemical systems

Not Recommended For: Applications requiring elasticity or high compressive recovery

Strengths:

Chemically inert and non-stick
Exceptionally wide temperature range
FDA-compliant and suitable for pharmaceutical/food-grade systems

Weaknesses:

Cold flow (creep) under pressure can lead to long-term deformation
Low elasticity — does not compress and rebound like rubber
May require backup support rings in high-pressure systems

3. Quick Selection Chart

Property	Viton (FKM)	EPDM	Buna-N (NBR)	PTFE (Teflon®)
Temperature Tolerance	★★★★☆ (to 230°C)	★★★☆☆ (to 150°C)	★★☆☆☆ (to 120°C)	★★★★★ (to 260°C)
Chemical Resistance	★★★★☆	★★★☆☆	★★☆☆☆	★★★★★
Steam Resistance	★☆☆☆☆	★★★★☆	★☆☆☆☆	★★★★☆
Oil Resistance	★★★★☆	★☆☆☆☆	★★★★☆	★★★★★
Cost Efficiency	★★☆☆☆ (higher cost)	★★★★☆	★★★★☆	★★☆☆☆ (moderate–high)
Elastic Recovery	★★★☆☆	★★★★☆	★★★★☆	★☆☆☆☆

4. Best Practices for Gasket Use

Match gasket material to your process media (always check a chemical compatibility chart)
Inspect regularly for signs of swelling, cracking, or flattening
Avoid over-tightening clamps to prevent deformation or cold flow
Clean gaskets after each processing cycle
Store unused gaskets in dry, UV-free environments
Replace on a scheduled basis in high-cycling or high-temp systems

5. Summary

Use Case	Recommended Gasket
High-temp processing	Viton (FKM)
Steam and water-based systems	EPDM
Oil and hydrocarbon-based fluids	Buna-N (NBR)
Universal chemical resistance (acids, cleaners, reagents)	PTFE (Teflon®)
Budget-friendly general use	Buna-N (NBR)
Food or pharma-grade chemical compatibility	PTFE (Teflon®)