Stainless steel flanges come in various types, each designed for specific applications and joining methods. Here are some of the most common types of stainless steel flanges:
1. Weld Neck Flanges (WN): Weld neck flanges have a long neck that is welded to the pipe, providing reinforcement and strength at the joint. They are commonly used in high-pressure and high-temperature applications. The flange's neck accommodates pipe expansion and contraction.
2. Slip-On Flanges (SO): Slip-on flanges slide over the pipe and are then welded in place. They are easy to align and install, making them suitable for low-pressure applications. They are not recommended for systems with high temperatures or extreme pressure conditions.
3. Socket Weld Flanges (SW): Socket weld flanges have a socket or hole to accommodate the pipe, and the pipe is then fillet-welded to the flange. They are primarily used for small-diameter, high-pressure pipelines and are well-suited for systems with limited space.
4. Threaded Flanges (TH): Threaded flanges have threads on the inner bore, allowing them to be screwed onto threaded pipes. They are used in low-pressure, non-critical applications and are common in small-diameter piping systems.
5. Blind Flanges (BL): Blind flanges are solid disks used to close the end of a pipe or vessel. They are commonly used to terminate pipelines and are sometimes used for pressure testing purposes.
6. Lap Joint Flanges (LJ): Lap joint flanges consist of two parts—a flat ring with bolt holes and a stub end that fits over the pipe. The stub end is free to rotate, making them suitable for systems that require frequent disassembly.
7. Orifice Flanges: Orifice flanges are used in orifice metering systems for flow measurement. They have concentric or eccentric holes (orifice bores) and are typically used with orifice plates to measure fluid flow rates.
8. Expander Flanges: Expander flanges are used to increase the pipe size from a smaller bore to a larger one. They are typically used in pipelines that require a smooth transition between different pipe sizes.
9. Reducing Flanges: Reducing flanges are used to connect pipes of different sizes. They have one size larger on one side and one size smaller on the other, allowing for a transition between pipes with different diameters.
10. Ring Type Joint (RTJ) Flanges: RTJ flanges are used in high-pressure and high-temperature applications. They have a groove and an accompanying ring gasket that ensures a tight seal under extreme conditions.
11. Spectacle Blind Flanges: Spectacle blind flanges are used in pipelines where regular maintenance or inspection is required. They can be rotated to block the flow in one direction while allowing flow in the other.
12. Swivel Ring Flanges: Swivel ring flanges are similar to lap joint flanges but have a rotating ring that allows for easy alignment of bolt holes. They are used in applications where bolt hole alignment is critical.
These are some of the common types of stainless steel flanges, and each serves specific purposes in various industries and applications. The choice of flange type depends on factors such as pressure, temperature, pipe size, and the specific requirements of the piping system.