New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What is the formula to find the difference in length for a two-pipe 30-degree equal spread offset?

1. Spread x diameter = DOL

2. Spread x constant = DOL

3. Travel x constant = DOL

4. Spread + distance = DOL

The correct answer is: Spread x constant = DOL

The correct approach to finding the difference in length for a two-pipe 30-degree equal spread offset involves understanding the concept of "constant" in relation to the spread of the pipes. The formula that incorporates the spread and a specific constant accurately provides the correct dimension of length, which is known as the "DOL" (Distance Over Length). In pipe fitting, the constant varies based on the angle of the offset and the diameter of the pipe. For a 30-degree offset, the constant is established through geometrical relationships that account for the spread (the horizontal distance between the two pipe ends) and the vertical rise or drop. By multiplying the spread by this constant, you get the DOL, which is crucial for ensuring that pipes fit correctly when making turns or obtaining necessary distances in installations. Understanding this formula is essential for pipe fitters when creating accurate layouts and making adjustments to measurements, particularly in adjusting for bends and offsets.