PPH Backing Rings
A PPH (Polypropylene Homopolymer) Backing Ring is a pipe fitting component used in flanged piping systems to provide support and alignment for stub end flanges. It is typically placed behind a PPH stub end and works together with a metal or plastic flange to create a secure bolted joint between pipes or equipment. PPH Backing Rings are precision-molded components used to reinforce and support flange connections in plastic piping systems. Made from Polypropylene Homopolymer (PPH), these rings are designed to be used in conjunction with stub ends or flanged joints, ensuring proper compression of the gasket and providing a leak-proof, strong mechanical joint.
Due to their high chemical resistance, lightweight, and non-corrosive properties, PPH backing rings are widely used in chemical processing, industrial fluid transport, wastewater management, and corrosive fluid pipelines.A PPH Backing Ring is a supporting ring used behind a stub end in flanged piping systems to ensure proper alignment, strength, and secure bolted connections.
- Chemical Resistance
- Low Maintenance Requirement
- Low Thermal Conductivity
- Long Service Life
- Easy Installation
- Corrosion Resistance
PPH Backing Rings Details
- OD – Outer Diameter
- PCD – Pitch Circle Diameter (for flange bolt circle)
- D – Outside Diameter (often used interchangeably with OD)
- Holes × Dia – Number of Bolt Holes × Diameter of Each Hole
| Nominal Pipe | Pipe OD (mm) | Ring OD D (mm) | Bolt Circle PCD (mm) | Holes × Dia (mm) |
| ½″ (DN15) | ~21.3 | ~89 | ~60.3 | 4 × ~16 |
| ¾″ (DN20) | ~26.7 | ~98.6 | ~69.8 | 4 × ~16 |
| 1″ (DN25) | ~33.4 | ~108 | ~79.4 | 4 × ~16 |
| 1¼″ (DN32) | ~42.2 | ~117.3 | ~88.9 | 4 × ~16 |
| 1½″ (DN40) | ~48.3 | ~127 | ~98.5 | 4 × ~16 |
| 2″ (DN50) | ~60.3 | ~152.4 | ~120.6 | 4 × ~19 |
| 2½″ (DN65) | ~73.0 | ~177.8 | ~139.7 | 4 × ~19 |
| 3″ (DN80) | ~88.9 | ~190.5 | ~152.4 | 4 × ~19 |
| 4″ (DN100) | ~114.3 | ~228.6 | ~190.5 | 8 × ~19 |
| Parameter / Property | Specification / Detail |
| Product Type | Backing Ring (PP-V Insert) |
| Material | PPH (Polypropylene Homopolymer) / PPH-Coated Steel |
| Application | Used with stub end for flanged pipe connections |
| Pressure Rating | PN10 / PN16 (depending on design) |
| Maximum Working Pressure | Up to 10–16 bar |
| Temperature Range | 0°C to +100°C (short-term up to 110°C) |
| Connection Method | Bolted flange connection |
| Size Range | DN15 to DN300 (½” to 12”) or up to DN400 |
| Standards | DIN 2501, ISO 7005, ANSI B16.5 |
| Color | Grey / Black / Natural |
| Compatibility | Suitable for PPH stub ends and thermoplastic piping systems |
| Design | Flat circular ring with bolt holes |
| Weight | Lightweight compared to metal rings |
| Strength | Provides strong mechanical support to flange joint |
| Surface Finish | Smooth and corrosion-free |
| Corrosion Resistance | Excellent (non-rusting, chemical resistant) |
| UV Resistance | Suitable for outdoor use |
| Durability | Long service life in harsh environments |
| Reusability | Can be dismantled and reused |
Strong Mechanical Support – Ensures proper flange alignment and even gasket compression.
Excellent Chemical Resistance – Ideal for corrosive environments including acid, alkali, and saltwater exposure.
Corrosion-Free Material – Will not rust or corrode, even under harsh conditions.
Lightweight and Durable – Easier to handle and install than metal alternatives.
UV & Weather Resistant – Suitable for outdoor applications.
Compatible with PPH Flanged Systems – Designed for perfect fit with PPH stub ends.
Reusable – Can be dismantled and reused for maintenance or system modification.
| Parameter | Specification |
| Standard Pressure Rating | PN10 / PN16 |
| Maximum Working Pressure | 10 – 16 bar (at 20°C) |
| Pressure Rating (Water Systems) | PN10 / PN16 |
| Hydrostatic Test Pressure | Typically 1.5 × PN (≈ 15–24 bar) |
| High Pressure Variant | PN16 (up to 16 bar) |
| Large Size Limitation | Often PN10 for bigger diameters |
| Applicable Standards | DIN, ISO, EN 1092, ANSI |
Custom Product Manufacturing Available
If you are searching for customized product designs that meet your requirements, don’t worry. Petron Thermoplast also offers custom product manufacturing services to meet the unique needs of various industries. Work with our expert engineers to create custom designs suited for your application.
Benefits of Using PPH Backing Rings
1. Strong Mechanical Support
- Provides firm support to flange joints
- Ensures proper alignment and stability during operation
2. Excellent Chemical Resistance
- Resistant to acids, alkalis, and corrosive fluids
- Ideal for chemical processing and wastewater systems
3. Corrosion-Free Material
- Does not rust or corrode like metal backing rings
- Suitable for harsh and aggressive environments
4. Uniform Load Distribution
- Distributes bolt load evenly across the flange
- Ensures better gasket compression and leak-proof sealing
5. Lightweight & Easy Handling
- Much lighter than metal rings
- Easier to transport, install, and handle
6. Easy Installation & Maintenance
- Simple bolted connection
- Can be easily assembled and dismantled
- Reduces maintenance time and effort
7. Reusable Design
- Can be removed and reused during maintenance or system changes
- Reduces overall operational cost
8. UV & Weather Resistance
- Suitable for outdoor installations
- Withstands environmental exposure without degradation
9. Cost-Effective Solution
- Lower cost compared to metal backing rings
- Long lifespan reduces replacement expenses
10. Compatibility with Thermoplastic Systems
- Designed to work perfectly with PPH stub ends and flanged piping systems
- Ensures reliable and secure connections
Types of PPH Backing Rings
Full PPH Backing Ring
- Made completely from PPH material
- Lightweight and highly resistant to chemicals
- Suitable for corrosive environments and chemical industries
PPH-Coated Backing Ring
- Steel ring coated with PPH layer
- Combines strength of metal + corrosion resistance of PPH
- Used in higher pressure and heavy-duty applications
Galvanized Steel Backing Ring (with PPH systems)
- Made of steel with zinc (galvanized) coating
- Provides strong mechanical support
- Used where mechanical strength is more important than chemical resistance
Stainless Steel Backing Ring (PPH compatible)
- Made from SS 304 / SS 316
- High strength and corrosion resistance
- Used in high-pressure or hygienic applications
Solid (Unreinforced) PPH Backing Ring
- Fully plastic, no metal reinforcement
- Used in low to medium pressure systems (PN10)
Reinforced Backing Ring
- Steel core with PPH coating
- Provides extra rigidity and load-bearing capacity
- Suitable for PN16 applications
PN10 Backing Ring
- Suitable for low to medium pressure systems
- Common for larger pipe sizes
DIN Standard Backing Ring
- Designed as per DIN 2501 / EN standards
- Common in European and Indian piping systems
ANSI / ASME Backing Ring
- Designed as per ANSI B16.5 (Class 150, etc.)
- Used in American standard systems
BS / ISO Standard Backing Ring
- Conforms to BS / ISO flange drilling patterns
- Ensures compatibility with different global systems
PN16 Backing Ring
- Used in higher pressure applications
- Thicker and stronger design
Applications of PPH Backing Rings
Process Industry
High Purity Applications
Electronic Industry
Electrical Industry
Semi-conductors Industry
Pharmaceutical Industry
Solar power panels
Sugar Industry
Paper & Pulp Industry
Nuclear Power Industry
Automotive Industry
DI water plants
Why Choose Petron Thermoplast?
Petron Thermoplast PPH Backing Ring are efficient, reliable, and essential tools in industrial automation, offering precise control of flow, pressure, and temperature. Proper selection, correct installation, and regular maintenance to ensure that these rings perform optimally in practical applications. As industrial automation technology continues to advance, the PPH Backing Ring will see broader applications and improved performance, providing a reliable foundation for safe, efficient, and stable production.
