Lap Joint Flanges: Specifications, Benefits, and Applications
Lap Joint Flanges Manufacturers Mumbai India. Best Price Exporter Supplier of Customize flange for Europe, US, UK & Gulf. Call +91-9769996991.
Lap joint flanges by Falcon are widely used in industrial piping systems, offering flexibility, easy alignment, and cost-effectiveness. These flanges are specifically designed to be used with a stub end, allowing for quick assembly and disassembly, making them ideal for frequent maintenance applications.
What is a Lap Joint Flange?
A lap joint flange is a type of flange that is loose and slides over the pipe, designed to work with a stub end that is welded to the pipe. The flange itself is not welded, allowing it to rotate for easy bolt alignment during installation.
Key Features of Lap Joint Flanges:
✔ Movable Design – Can rotate around the pipe for easy alignment.
✔ Used with a Stub End – The stub end is welded to the pipe, while the flange remains loose.
✔ Ideal for Low-Pressure Applications – Suitable for non-critical applications.
✔ Cost-Effective – Reusable, making it an economical choice for pipelines requiring frequent adjustments.
Types of Lap Joint Flanges
Lap joint flanges are categorized based on face type and pressure rating.
1. Standard Lap Joint Flange
- Designed for low to medium-pressure systems.
- Works with a stub end for alignment flexibility.
2. Raised Face (RF) Lap Joint Flange
- Has a slightly raised surface for better gasket compression.
- Suitable for moderate pressure and temperature applications.
3. Flat Face (FF) Lap Joint Flange
- Features a completely flat sealing surface.
- Used in low-pressure, non-critical environments.
Benefits of Using Lap Joint Flanges
✔ Easy Alignment – The flange can rotate, making bolt hole alignment simple.
✔ Cost-Effective – Can be reused, reducing material costs.
✔ Ideal for Frequent Maintenance – Easily removable for cleaning or replacement.
✔ Compatible with Various Pipe Materials – Can be used with stainless steel, carbon steel, and other materials.
✔ Corrosion Resistance – Available in coated and alloy steel variants for enhanced durability.
Lap Joint Flange Specifications
Lap joint flanges must comply with international industry standards to ensure compatibility, safety, and durability.
1. Standard Specifications
Lap joint flanges are manufactured according to the following industry standards:
- ASME/ANSI B16.5 – Covers flanges up to 24 inches.
- ASME B16.47 – Used for large-diameter flanges above 24 inches.
- EN 1092-1 – European standard for flange connections.
- DIN 2642 – German standard for lap joint flanges.
- JIS B2220 – Japanese standard for steel flanges.
2. Material Specifications
Lap joint flanges are available in various materials based on corrosion resistance, temperature, and pressure requirements.
| Material | Properties & Applications |
|---|---|
| Carbon Steel | Cost-effective, used in general piping applications. |
| Stainless Steel | Corrosion-resistant, ideal for chemical and marine industries. |
| Alloy Steel | High strength, suitable for extreme temperatures. |
| Duplex Steel | Resistant to corrosion and stress cracking. |
| Copper-Nickel | Used in marine and desalination plants. |
3. Size & Dimensions
Lap joint flanges come in various sizes and pressure ratings.
Common Lap Joint Flange Dimensions (ANSI B16.5 Standard)
| Nominal Pipe Size (NPS) | Outer Diameter (OD) mm | Bolt Circle Diameter (BCD) mm | Number of Bolt Holes |
|---|---|---|---|
| ½” | 90 | 60 | 4 |
| 1″ | 125 | 90 | 4 |
| 2″ | 150 | 120 | 4 |
| 4″ | 230 | 190 | 8 |
| 6″ | 280 | 241 | 8 |
| 8″ | 345 | 298 | 8 |
| 10″ | 405 | 362 | 12 |
| 12″ | 485 | 432 | 12 |
(Note: Dimensions may vary depending on pressure rating and specific industry standards.)
4. Pressure Ratings
Lap joint flanges are available in different pressure classes, which indicate their maximum pressure handling capacity.
| Class (ANSI/ASME B16.5) | Maximum Pressure (PSI) |
|---|---|
| Class 150 | 285 PSI |
| Class 300 | 740 PSI |
| Class 600 | 1,480 PSI |
| Class 900 | 2,220 PSI |
| Class 1500 | 3,700 PSI |
| Class 2500 | 6,170 PSI |
Higher pressure ratings offer better strength and durability in demanding applications.
Common Applications of Lap Joint Flanges
🔹 Oil & Gas Industry – Used in pipelines requiring frequent dismantling.
🔹 Chemical Processing Plants – Provides flexibility in corrosive environments.
🔹 Water Treatment Systems – Common in water purification and distribution.
🔹 Power Plants – Used in low to moderate-pressure piping systems.
🔹 Marine & Shipbuilding – Resistant to saltwater corrosion.