New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

For bolting a 12 inch, 600 class flange joint, what is the size and number of studs required?

1. 1 inch, 16

2. 1-1/4 inch, 20

3. 1-1/2 inch, 24

4. 3/4 inch, 12

The correct answer is: 1-1/4 inch, 20

For a 12 inch, 600 class flange joint, the specification typically indicates the size and number of bolts required to ensure a proper seal under the expected pressure conditions. In this context, the answer involving a stud size of 1-1/4 inch and a count of 20 is correct. This choice is in alignment with established engineering guidelines and industry practices specific to flanged connections at this diameter and pressure class. The 600 class denotes a higher pressure rating, which translates to the need for larger and more bolts to distribute the load effectively and maintain the integrity of the joint. The specified 1-1/4 inch size reflects the need for enhanced strength and resistance to the forces that can be present in such high-pressure situations. Furthermore, the number of 20 studs ensures that the load is well-distributed around the flange, minimizing the risk of failures such as leaks or mechanical malfunctions. Understanding the components and their specifications is crucial for pipe fitters working with flanged joints, as proper bolting ensures safety and reliability in piping systems.