In industrial automation and process measurement, sealing performance directly affects the stability, accuracy, and lifespan of measuring instruments. Whether it is a pressure transmitter, ultrasonic level sensor, or hydraulic pressure sensor, selecting the correct sealing material is critical for long-term reliable operation.

Different media, temperatures, pressures, and environmental conditions require different sealing solutions. Choosing the wrong seal material can lead to leakage, corrosion, sensor failure, or costly downtime.

As a professional industrial sensor manufacturer, Pokcenser provides reliable measurement solutions for harsh industrial environments. This guide explains the characteristics of common sealing materials and how to select the best option based on real application conditions.

Common Seal Materials and Their Industrial Applications

1. Nitrile Rubber (NBR)

Características

• Excellent oil resistance
• Good wear resistance
• Strong adhesion performance
• Economical and widely used
• Poor ozone and low-temperature resistance
• Limited high-temperature capability

Temperatura de funcionamiento

• Typical range: -20°C to +80°C

Recommended Applications

NBR seals are commonly used in:

• Hydraulic systems
• Lubrication equipment
• Oil-based industrial media
• General machinery pressure sensors

For example, NBR is widely used in:

• Pokcenser Hydraulic Pressure Sensors 
• Oil pressure monitoring systems
• Industrial machinery transmitters

Not Recommended For

• Strong oxidizing chemicals
• Entornos de alta temperatura
• Outdoor ozone exposure

2. Fluororubber (FKM / VITON)

Características

• Outstanding chemical resistance
• Excellent oil resistance
• Superior high-temperature performance
• Good compatibility with petroleum products
• Longer service life in harsh environments

Temperatura de funcionamiento

• Typical range: -20°C to +200°C

Recommended Applications

FKM sealing rings are ideal for:

• Depósitos químicos
• Petrochemical industries
• Hydraulic oil systems
• Fuel and solvent applications
• High-temperature industrial processes

FKM is frequently selected for:

• Pokcenser Intrinsically Safe Pressure Transmitters 
• Hazardous-area pressure monitoring
• Corrosive liquid measurement

Advantages for Industrial Sensors

Compared with ordinary rubber materials, FKM provides:

• Better sealing stability
• Lower maintenance frequency
• Improved corrosion resistance
• Longer sensor lifespan

3. EPDM Rubber

Características

• Excellent weather resistance
• Outstanding ozone resistance
• Strong steam and hot-water resistance
• Wide low-temperature capability
• Poor compatibility with oils and solvents

Temperatura de funcionamiento

• Typical range: -60°C to +130°C

Recommended Applications

EPDM is suitable for:

• Water treatment systems
• Steam pipelines
• Cooling systems
• Non-oily media environments

Common industrial uses include:

• Water pressure sensors
• Sistemas de calefacción, ventilación y aire acondicionado
• Environmental monitoring equipment

Best Choice For

• Clean water applications
• Outdoor industrial installations
• Moisture-rich environments

4. Silicone Rubber (SIL)

Características

• Exceptional high and low temperature resistance
• Excellent aging resistance
• Good flexibility
• Safe for hygienic applications
• Lower mechanical strength

Temperatura de funcionamiento

• Typical range: -70°C to +260°C

Recommended Applications

Silicone seals are commonly used in:

• Food processing equipment
• Pharmaceutical industries
• High-temperature instruments
• Outdoor monitoring devices

Limitations

Silicone rubber is generally not recommended for:

• Heavy oil environments
• High-pressure hydraulic systems

5. PTFE (Polytetrafluoroethylene)

Características

• Outstanding chemical stability
• Excellent corrosion resistance
• Extremely wide media compatibility
• High-temperature resistance
• Low friction coefficient

Recommended Applications

PTFE is ideal for:

• Strong acid or alkali environments
• Corrosive chemical tanks
• High-purity liquid systems
• Chemical process automation

It is commonly used with:

• Pokcenser Ultrasonic Level Sensors 
• Chemical storage tank monitoring
• Sistemas de tratamiento de aguas residuales

Why PTFE Matters

For ultrasonic level transmitters operating in chemical tanks, PTFE seals significantly improve:

• Chemical resistance
• Long-term sealing reliability
• Sensor durability

6. Metal Sealing Rings

Características

• Extremely high pressure resistance
• Excellent temperature resistance
• Superior structural strength
• Strong corrosion resistance
• Long service life in extreme environments

Recommended Applications

Metal seals are widely used in:

• High-pressure process industries
• Petrochemical plants
• Power stations
• Heavy industrial equipment
• Extreme-temperature systems

Lo mejor para

Applications where ordinary rubber seals may fail due to:

• High pressure
• Severe vibration
• Aggressive chemicals
• Extreme temperatures

How to Choose the Right Seal Material

Selecting the correct sealing ring depends on several key factors.

1. Medium Compatibility

Different media require different seal materials.

Medium Type	Recommended Material
Aceite hidráulico	NBR / FKM
Corrosive chemicals	PTFE / Metal
Water & steam	EPDM
High-temperature fluids	FKM / SIL
Solvents & fuels	FKM

2. Operating Temperature

Temperature resistance is one of the most important selection factors.

Temperatura	Recommended Material
Low temperature	EPDM / SIL
Medium temperature	NBR
High temperature	FKM / SIL
Temperatura extrema	Metal seals

3. Pressure Conditions

High-pressure systems require stronger sealing materials.

Recommended solutions:

• Metal sealing rings
• Reinforced FKM seals
• High-strength industrial elastomers

These are especially important for:

• Hydraulic pressure transmitters
• Heavy-duty machinery sensors
• Industrial oil pressure systems

4. Chemical Resistance

Chemical compatibility determines long-term sensor reliability.

For aggressive chemicals:

• Choose PTFE or FKM
• Avoid ordinary rubber materials

This is particularly critical for:

• Chemical tank level measurement
• Industrial wastewater systems
• Acid and alkali storage monitoring

5. Cost vs Performance

Lower-cost materials may reduce initial expenses, but premium materials often provide:

• Longer service life
• Reduced maintenance
• Better measurement stability
• Lower downtime costs

For demanding industrial environments, higher-quality sealing materials typically deliver better long-term ROI.

Why Seal Material Selection Matters for Industrial Sensors

Inaccurate seal selection can cause:

• Sensor leakage
• Pressure instability
• Signal fluctuation
• Corrosion damage
• Premature equipment failure

En Pokcenser Industrial Sensors, sealing material selection is optimized according to different industrial applications to ensure:

• Gran precisión de medición
• Stable long-term performance
• Reliable operation in harsh environments
• Reducción de los costes de mantenimiento

FAQ About Seal Materials for Measuring Instruments

Which sealing material is best for oil applications?

NBR and FKM are the most commonly used materials for oil-based media because of their excellent oil resistance.

What seal material should be used for chemical tanks?

PTFE and FKM are recommended due to their strong chemical corrosion resistance.

Which sealing material works best in high-temperature environments?

FKM, silicone rubber, and metal seals are ideal for high-temperature industrial applications.

Why is PTFE commonly used in ultrasonic level sensors?

PTFE offers excellent chemical resistance and stability, making it ideal for corrosive liquid level monitoring applications.

Conclusión

Choosing the right sealing material is essential for improving the performance, reliability, and lifespan of industrial measuring instruments.

Whether your application involves:

• Depósitos químicos
• Hydraulic systems
• Tratamiento del agua
• High-temperature processes
• Corrosive media

Selecting the proper seal material can significantly improve equipment stability and reduce maintenance costs.

If you are looking for reliable industrial sensors with optimized sealing solutions, explore the full range of products from Pokcenser.