Flanges are essential components in piping systems, used to connect pipes, valves, pumps, and other equipment to create a secure and leak-proof system. They come in various types, each designed to meet specific requirements of pressure, temperature, and ease of maintenance. Here’s an overview of the main types of flanges:

1. Slip-On Flange

The Slip-On Flange is one of the most commonly used types. This flange is designed to slide over the end of the pipe and is then welded both inside and outside to create a secure connection. The primary advantage of Slip-On Flanges is their ease of alignment and lower cost compared to other flange types. However, their pressure rating is lower due to the reduced wall thickness after welding, making them less suitable for high-pressure applications.

2. Weld Neck Flange

The Weld Neck Flange features a long neck that fits over the pipe and is welded to it, providing a smooth transition from the pipe to the flange. This design reduces stress concentration and enhances the strength of the connection. Weld Neck Flanges are ideal for high-pressure and high-temperature applications due to their robust construction. However, they require precise alignment during installation and are more expensive than other types.

3. Blind Flange

Blind Flanges are solid and do not have any opening. They are used to seal the end of a pipe or vessel, providing a complete closure. This type of flange is essential for high-pressure applications where a secure seal is crucial. The main disadvantage is that Blind Flanges are not suitable for situations where frequent access to the pipe is necessary, as they are intended to remain permanently in place.

4. Threaded Flange

Threaded Flanges have internal threads that match the external threads of the pipe, allowing them to be screwed into place. This design eliminates the need for welding, making them easier to install and remove. They are ideal for low-pressure applications and situations where welding is not feasible. However, the threaded connection can wear out over time and may not be suitable for high-pressure or high-temperature applications.

5. Socket Weld Flange

Socket Weld Flanges are designed with a socket into which the pipe is inserted and then welded around the outside. This type of flange provides a smooth bore and strong connection, reducing turbulence and pressure drop. They are commonly used in high-pressure and high-temperature applications. However, they are not ideal for pipes that undergo significant thermal expansion or contraction.

6. Lap Joint Flange

Lap Joint Flanges consist of two components: a backing flange and a loose flange that fits over the pipe. This design allows for easy alignment and adjustment, making it suitable for applications where the joint needs to be frequently dismantled. While convenient, Lap Joint Flanges require a matching backing flange, which can add to the overall cost.

7. Orifice Flange

Orifice Flanges are specifically designed for use with orifice meters to measure flow rates. They feature bolt holes for pressure taps and a dedicated area for flow measurement. This specialized design is crucial for accurate flow measurement and pressure drop calculations but is less versatile for general applications.

8. Raised Face Flange

Raised Face Flanges have a slightly elevated area around the flange’s perimeter, which provides a larger sealing surface. This design enhances the tightness of the joint and is often used in high-pressure applications. However, the raised face can be prone to damage during handling.

9. Flat Face Flange

Flat Face Flanges have a flat sealing surface that aligns with the pipe’s surface. This design ensures even pressure distribution and is typically used with cast iron flanges. While effective for distributing pressure, Flat Face Flanges are less effective at sealing compared to Raised Face Flanges, especially in high-pressure situations.

10. RTJ Flange (Ring Type Joint)

RTJ Flanges use a metal ring to create a seal between the flange faces. This type of flange is well-suited for high-pressure and high-temperature applications due to its robust sealing capabilities. However, it requires precise machining and installation.

11. Swivel Flange

Swivel Flanges are similar to Lap Joint Flanges but feature the ability to rotate around the pipe. This flexibility can be beneficial in complex installations. Swivel Flanges are generally more expensive and less commonly used compared to other types.

Each type of flange is tailored for specific applications, balancing factors such as pressure, temperature, ease of maintenance, and cost. Selecting the appropriate flange type ensures a reliable and efficient piping system.