New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

A malleable iron coupling with 4 ribs is identified as having what type of threads?

1. Right-hand threads

2. Left-hand threads

3. Mixed threads

4. No threads

The correct answer is: Right-hand threads

The identification of a malleable iron coupling with 4 ribs as having right-hand threads is accurate because it aligns with standard practices in piping systems. Right-hand threads are the most commonly used type in piping connections, which allows for easier installation as they follow the natural motion of tightening. This convention means that turning the coupling in a clockwise direction will tighten the connection, which is intuitive for most workers. Malleable iron is frequently utilized in plumbing and piping applications for its strength and durability, and the inclusion of ribs enhances the coupling's grip and ability to hold under pressure. The fact that the coupling is described as having 4 ribs suggests that it is designed for robust connections, making the use of right-hand threads suitable. The acknowledgment of left-hand threads would indicate a less common application typically reserved for specialized situations, while the concepts of mixed threads or the absence of threads do not fit the description of a standard coupling intended for general use in piping systems. Therefore, the designation of right-hand threads aligns well with industry standards and practices surrounding malleable iron fittings.