How Are Pipes And Flanges Connected?

1. **Welded Connection:**

- **Welding:** The most common method for permanently joining pipes and flanges is welding. In this process, the ends of the pipe and flange are aligned and fusion-welded together. Welding is strong and reliable but requires skilled labor and specialized equipment.

2. **Threaded Connection:**

- **Threaded flanges:** Pipes with threads on their ends can be screwed into threaded holes in the flanges. This method is easy to install and remove, suitable for low-pressure applications, and is commonly used in piping systems that may need to be disconnected for maintenance or replacement.

3. **Solvent weld Connection:**

- **Solvent weld flanges:** These flanges are designed to be joined using solvent cement, which is applied to the outside of the pipe and flange before they are pressed together. This creates a chemical bond and is commonly used in non-pressurized piping systems, such as drainage piping.

4. **Hydraulic Flange Connection:**

- **Hydraulically expanded flanges:** This method involves expanding the diameter of the pipe within the flange to create a permanent joint. It is commonly used in high-pressure applications where a strong, leak-free connection is required.

5. **Clamp Connection:**

- **Ring gasket and bolted flanges:** This is a common method for joining flanges in lower-pressure applications. A gasket is placed between the flanges, and bolts are tightened to compress the gasket and create a seal. This method is easier to install and remove compared to welding and can be used in a wide range of temperatures and pressures.

6. **Lug Connection:**

- **Lugged flanges:** These flanges have protruding lugs or studs that pass through holes in the pipe and are secured with nuts. This method is often used in high-pressure and high-temperature applications.

7. **Friction Grip Connection:**

- **Friction grip flanges:** Also known as compression flanges, these flanges rely on friction to create a seal between the flange and the pipe. The flange is tightened around the pipe, creating a secure connection.

8. **Bolted Connection:**

- **Bolted flanges:** This is similar to the clamp connection but uses bolts to secure the flanges together. Bolted connections are versatile and can be used in a wide range of applications.

The choice of connection method depends on factors such as the pressure and temperature of the fluid, the type of fluid, the required durability and leak-tightness, and the ease of installation and maintenance. Each method has its advantages and is chosen based on the specific requirements of the piping system.