Which of the following describes a “coupling” in pipefitting?

A coupling in pipefitting specifically refers to a device designed to connect two pipes together. Couplings are used to create a secure joint that allows fluid to flow seamlessly through the connected pipes. They can be made from various materials such as metal, plastic, or rubber, depending on the application, and they come in different types, such as threaded, slip, or compression couplings. This makes them fundamental components in piping systems for both residential and industrial applications.

In contrast, other choices do not correctly define a coupling. The description of a type of elbow fitting refers to a different component that allows for changes in direction in piping systems. A sealant for leaks pertains to materials used to prevent leaks at joints or fittings but is not a physical connector like a coupling. Meanwhile, a tool for tightening pipe joints refers to instruments like wrenches or pipe vises, which are used to secure and tighten connections but do not serve the purpose of connecting two pipes directly.