New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What is the distance (end to center) for an 8 inch long radius 45-degree elbow using the alternative method?

1. 3 inches

2. 4 inches

3. 5 inches

4. 6 inches

The correct answer is: 5 inches

In piping, when determining the distance from the end of a fitting to the centerline (known as the "end to center distance"), specific dimensions are established for different types of fittings. For an 8-inch long radius 45-degree elbow, the alternative method refers to a standard calculation which involves the radius of the elbow. The long radius of the elbow is typically given as 1.5 times the nominal pipe diameter. For an 8-inch elbow, the long radius would thus be 12 inches (1.5 x 8 inches). When calculating the end to center distance for a 45-degree elbow, the method accounts for the radius of the elbow in relation to the pipe size. Using the formula for the end to center distance for a long radius elbow of this type, it results in a distance of 5 inches. The typical formula used is: End to center distance = Radius of elbow – (Diameter of pipe / 2) Since the radius is 12 inches for an 8-inch elbow, and factoring in the diameter, you reach the final calculation. This understanding of the relationship between the dimensions and the elbow's specifics helps the technician accurately determine pipe layout requirements. Thus, the correct value for the end to center distance