The face to center distance of a 4" welded long radius 45 degree elbow is:

To determine the face-to-center distance of a 4" welded long radius 45-degree elbow, it's important to understand the specifications of pipe fittings and how they are measured. The face-to-center distance refers to the distance from the end of the fitting where it connects to the pipe (the face) to the centerline of the fitting.

In the case of a long radius elbow, the radius of the curvature is longer than that of a short radius elbow. For a 4" diameter pipe, the long radius elbow typically has a radius that is 1.5 times the diameter of the pipe. Therefore, the radius for a 4" long radius elbow is 6 inches (1.5 times 4 inches).

When calculating the face-to-center distance for a 45-degree elbow, this distance is generally derived from a standard formula or table often used in piping to provide quick reference for fittings. According to these tables, the face-to-center distance for a 4" long radius 45-degree elbow is commonly listed as 2.5 inches.

Therefore, the choice indicating 2 1/2 inches accurately reflects this established measurement for a 4" welded long radius 45-degree elbow, ensuring that installation adheres to