Rubber expansion joints are important flexible components widely used in industrial piping systems. They are designed to absorb vibration, reduce mechanical noise, compensate for thermal expansion, and protect connected equipment such as pumps, valves and pipelines.
When selecting a rubber expansion joint, the pressure rating is one of the most important technical factors. Different projects may require different pressure classes, such as PN10, PN16, PN25 and ANSI Class 150. Choosing the correct pressure rating ensures safe operation, longer service life and reliable performance of the entire piping system.
As a professional rubber expansion joint manufacturer in China, Hongze Pipe (Zhengzhou Hongze Valve Pipeline Equipment Co., Ltd.) provides customized rubber expansion joints according to working pressure, temperature, medium, flange standards and movement requirements.
This article explains the differences between PN10, PN16, PN25 and Class 150 rubber expansion joints and provides guidance on how to select the right pressure rating for industrial applications.
1. What Does Rubber Expansion Joint Pressure Rating Mean?
The pressure rating of a rubber expansion joint refers to the maximum allowable working pressure that the product can withstand under specified operating conditions.
Pressure ratings are commonly expressed in two systems:
PN Rating System
PN stands for Pressure Nominal and is commonly used in European and international standards.
Examples:
- PN10 = 10 Bar nominal pressure
- PN16 = 16 Bar nominal pressure
- PN25 = 25 Bar nominal pressure
Class Rating System
Class ratings are mainly used in ASME/ANSI standards.
Examples:
- Class 150
- Class 300
- Class 600
The pressure capability of a rubber expansion joint depends not only on the pressure rating but also on:
- Rubber material
- Reinforcement layers
- Flange design
- Operating temperature
- Installation conditions
- Working medium
2. PN10 Rubber Expansion Joint
Working Pressure
PN10 rubber expansion joint means:
Maximum nominal working pressure: 10 Bar (1.0 MPa)
PN10 is commonly used for low-pressure piping systems.
Typical Applications
PN10 rubber expansion joints are suitable for:
- Water supply systems
- HVAC pipelines
- Cooling water circulation systems
- Building service pipelines
- Low-pressure industrial applications
Advantages
The main advantages include:
- Economical solution
- Good vibration absorption performance
- Excellent flexibility
- Easy installation and maintenance
However, PN10 rubber expansion joints are not recommended for systems with frequent pressure fluctuations or high-pressure operation.
3. PN16 Rubber Expansion Joint
Working Pressure
PN16 rubber expansion joint means:
Maximum nominal working pressure: 16 Bar (1.6 MPa)
PN16 is one of the most commonly used pressure ratings for industrial rubber expansion joints.
Typical Applications
PN16 rubber expansion joints are widely used in:
- Industrial water pipelines
- Pump inlet and outlet connections
- Fire protection systems
- Chemical processing pipelines
- Power plant cooling systems
- Municipal water projects
Why Is PN16 Widely Used?
Compared with PN10, PN16 provides:
- Higher pressure resistance
- Better safety margin
- Improved performance under pressure fluctuation
For many industrial projects, PN16 is considered the standard choice because it provides a good balance between performance and cost.
Hongze Pipe supplies PN16 rubber expansion joints with various options:
- EPDM rubber bellows
- NBR rubber bellows
- FKM/Viton rubber bellows
- Carbon steel flanges
- Stainless steel flanges
- DIN PN16 and EN1092-1 PN16 connections
4. PN25 Rubber Expansion Joint
Working Pressure
PN25 rubber expansion joint means:
Maximum nominal working pressure: 25 Bar (2.5 MPa)
PN25 is designed for high-pressure piping systems.
Typical Applications
PN25 rubber expansion joints are commonly used in:
- High-pressure water systems
- Industrial process pipelines
- Chemical plants
- Power generation facilities
- Heavy-duty pumping systems
Features of PN25 Rubber Expansion Joints
Because of the higher pressure requirement, PN25 expansion joints require:
- High-quality rubber compounds
- Strong reinforcement layers
- Reliable flange connections
- Strict manufacturing control
Correct installation is especially important for PN25 applications because excessive movement, misalignment or improper bolt tightening may affect service life.
5. Class 150 Rubber Expansion Joint
What Is Class 150?
Class 150 is an ASME/ANSI pressure class commonly used in international industrial projects.
The approximate pressure rating is:
150 PSI (approximately 10.3 Bar)
Although Class 150 and PN10 have similar pressure levels, they are not exactly the same because flange dimensions and standards are different.
Typical Applications
Class 150 rubber expansion joints are widely used in:
- Oil and gas pipelines
- Industrial equipment connections
- Chemical processing systems
- Cooling water systems
- Pump and compressor applications
They are usually supplied with:
- ANSI B16.5 Class 150 flanges
- RF or FF flange faces
- Carbon steel or stainless steel flanges
6. Comparison Between PN10, PN16, PN25 and Class 150
| Pressure Rating | Working Pressure | Standard System | Typical Applications |
|---|---|---|---|
| PN10 | 10 Bar | EN / DIN | Water, HVAC, low-pressure systems |
| PN16 | 16 Bar | EN / DIN | Industrial pipelines, pumps, water treatment |
| PN25 | 25 Bar | EN / DIN | High-pressure industrial systems |
| Class 150 | 150 PSI (≈10 Bar) | ASME / ANSI | Oil, gas and industrial projects |
7. Factors Affecting Rubber Expansion Joint Pressure Performance
7.1 Rubber Material Selection
Different rubber materials provide different pressure, temperature and chemical resistance.
EPDM Rubber Expansion Joint
EPDM is widely used for water applications.
Suitable for:
- Cooling water
- Hot water
- HVAC systems
- General industrial water
Advantages:
- Excellent aging resistance
- Good weather resistance
- Good temperature resistance
NBR Rubber Expansion Joint
NBR is commonly selected for oil-related applications.
Suitable for:
- Hydraulic oil
- Fuel oil
- Petroleum products
Advantages:
- Excellent oil resistance
- Good mechanical strength
FKM / Viton Rubber Expansion Joint
FKM is used for demanding applications.
Suitable for:
- High-temperature media
- Chemical applications
- Special industrial environments
Advantages:
- Excellent chemical resistance
- High temperature performance
7.2 Flange Standards
The flange connection directly affects pressure performance.
Common flange standards include:
- EN1092-1 PN10 / PN16 / PN25
- DIN PN16
- ASME B16.5 Class 150
- JIS 10K
- AWWA C207
Flange materials can include:
- Carbon steel
- Stainless steel
- Ductile iron
The correct flange standard should always match the pipeline system requirements.
7.3 Installation Requirements
Proper installation is essential for the service life of rubber expansion joints.
Important installation requirements:
- Ensure correct pipeline alignment
- Avoid excessive stretching during installation
- Prevent twisting of rubber bellows
- Tighten bolts evenly
- Install control rods when required
- Avoid direct contact with sharp objects
Incorrect installation may cause:
- Rubber cracking
- Flange leakage
- Excessive deformation
- Premature failure
8. How to Select the Correct Rubber Expansion Joint Pressure Rating?
Before selecting a rubber expansion joint, engineers should confirm the following information:
1. Working Pressure
Example:
- Low-pressure water system → PN10
- Industrial water system → PN16
- High-pressure system → PN25
2. Working Temperature
Temperature affects the allowable pressure of rubber materials.
3. Working Medium
Different media require different rubber compounds:
- Water → EPDM
- Oil → NBR
- Chemical media → FKM or special rubber
4. Flange Standard
Confirm:
- DIN
- EN
- ANSI
- JIS
- AWWA
5. Movement Requirements
Including:
- Axial movement
- Lateral movement
- Angular movement
9. Common Applications of Rubber Expansion Joints
Rubber expansion joints are widely used in many industries:
Water Treatment
Used for:
- Pump connections
- Water pipelines
- Filtration systems
Power Plants
Used for:
- Cooling water systems
- Equipment vibration isolation
Petrochemical Industry
Used for:
- Process pipelines
- Chemical transportation systems
HVAC Systems
Used for:
- Chillers
- Pumps
- Air conditioning pipelines
Mining Industry
Used for:
- Slurry pipelines
- Heavy-duty industrial systems
10. Why Choose Hongze Pipe Rubber Expansion Joints?
Hongze Pipe (Zhengzhou Hongze Valve Pipeline Equipment Co., Ltd.) is a professional manufacturer specializing in pipeline expansion solutions.
Our main products include:
- Rubber Expansion Joints
- Metal Bellows Expansion Joints
- Flexible Rubber Connectors
- Industrial Pipe Fittings
- Valves and Pipeline Accessories
We provide customized rubber expansion joint solutions according to:
✔ Pressure rating requirements
✔ Temperature conditions
✔ Pipeline movement requirements
✔ Flange standards
✔ Industrial application requirements
Our products include:
✔ PN10 Rubber Expansion Joints
✔ PN16 Rubber Expansion Joints
✔ PN25 Rubber Expansion Joints
✔ ANSI Class 150 Rubber Expansion Joints
✔ EPDM, NBR and FKM Rubber Materials
✔ DIN, EN, ANSI and JIS Flange Connections
Hongze Pipe products are widely used in:
- Water treatment plants
- Power plants
- Petrochemical projects
- HVAC systems
- Mining projects
- Industrial pipeline systems
For technical consultation and quotation:
Company: Zhengzhou Hongze Valve Pipeline Equipment Co., Ltd.
Website: https://www.hongzepipe.com
Email: export@hongzepipe.com
WhatsApp: +86 15838027988
Hongze Pipe is committed to providing reliable rubber expansion joint solutions and professional pipeline equipment services for customers worldwide.
Conclusion
Selecting the correct pressure rating is essential for the safe and reliable operation of rubber expansion joints.
PN10, PN16, PN25 and Class 150 represent different pressure standards for different industrial applications. The correct choice depends on working pressure, temperature, medium, flange standard and movement requirements.
As a professional rubber expansion joint manufacturer, Hongze Pipe provides high-quality customized expansion solutions for global customers with professional engineering support and manufacturing capability.
Contact Hongze Pipe for your rubber expansion joint requirements and professional pipeline solutions.