New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What is the end to center measurement of a reducing 90 degree long radius elbow?

1. 1 NPS

2. 2-1/2 NPS

3. 1-1/2 NPS

4. 3 NPS

The correct answer is: 1-1/2 NPS

The end to center measurement of a reducing 90 degree long radius elbow is determined by the size of the pipes being connected, specifically focusing on the larger diameter of the reducing elbow. In this case, the term "NPS" stands for Nominal Pipe Size, which is a standard that represents the diameter of the pipe. For a reducing 90 degree long radius elbow, the long radius aspect means that the radius of curvature is typically 1.5 times the nominal pipe size (NPS) of the large end of the elbow. This rule is critical as it defines the relationship between the physical measurements of the elbow and its respective sizes. In this scenario, a measurement of 1-1/2 NPS represents the end to the center dimension for this type of elbow. It aligns with standard piping practices where elbows of different sizes have specific measurement characteristics. Therefore, the answer reflects the established standards for pipe fittings, specifically for long radius reducing elbows, which simplifies and standardizes installations within various piping systems.