A pipe coupling is a device used to connect two pipes together. It’s essentially a fitting that joins two pipes of the same diameter in a straight line. Couplings come in various materials such as steel, brass, plastic, or copper, and they can have different designs depending on the specific application.

Common types of pipe couplings include:

1. Compression Coupling: This type of coupling uses compression fittings to join pipes together. It consists of two parts: a compression nut and a compression ring (often called a ferrule). When the nut is tightened, it compresses the ring onto the pipe, creating a tight seal.
2. Threaded Coupling: Threaded couplings have male threads on one end and female threads on the other end, allowing pipes to be screwed together. They are commonly used in plumbing and other applications where a secure connection is required.
3. Slip Coupling: Also known as a repair coupling, slip couplings are used to repair a broken or leaking pipe. They consist of two parts that slide over the ends of the pipes to be joined and are secured in place with clamps or screws.
4. Flanged Coupling: Flanged couplings have flanges on each end that are bolted together to join pipes. They are commonly used in applications where the pipes need to be easily disconnected for maintenance or repair.
5. Grooved Coupling: Grooved couplings have grooves on each end that match up when the pipes are joined together. A gasket is placed between the grooves to create a tight seal, and the coupling is secured in place with bolts or clamps.
6. Flexible Coupling: Flexible couplings are used to join pipes that may not be perfectly aligned or that need to accommodate some movement or vibration. They typically consist of a rubber or elastomeric sleeve with clamps or bands at each end to secure it to the pipes.

Overall, pipe couplings play a crucial role in various industries and applications, providing a reliable and leak-proof connection between pipes.