What is another name for a double back elbow?

What is another name for a double back elbow?

• A. Lobster back
• B. Swept elbow
• C. Piano elbow
• D. Angle tee

Answer: (A)

The main idea here is recognizing a common nickname for a specific pipe-fitting shape. A double back elbow describes a configuration with two back-to-back bends in a line, which creates a rounded, arced silhouette. In many trades, that particular shape is colloquially called a lobster back, because the curved back of a lobster resembles the two closely spaced bends. That familiar imagery makes lobster back the natural, well-attested name for this elbow arrangement. The other terms refer to different fittings or shapes. A swept elbow describes a single bend with a large radius, not a double bend. A piano elbow isn’t a standard term used for this configuration, and an angle tee is a three-way fitting that forms a T shape, not a curved elbow.

The main idea here is recognizing a common nickname for a specific pipe-fitting shape. A double back elbow describes a configuration with two back-to-back bends in a line, which creates a rounded, arced silhouette. In many trades, that particular shape is colloquially called a lobster back, because the curved back of a lobster resembles the two closely spaced bends. That familiar imagery makes lobster back the natural, well-attested name for this elbow arrangement.

The other terms refer to different fittings or shapes. A swept elbow describes a single bend with a large radius, not a double bend. A piano elbow isn’t a standard term used for this configuration, and an angle tee is a three-way fitting that forms a T shape, not a curved elbow.