FREE Certified Pipefitter Pipe Fabrication and Joining Questions and Answers

Question 1

A pipefitter is tasked with assembling a flanged joint on a high-pressure steam line. What is the correct procedure for tightening the bolts to ensure a leak-free seal?

Accepted Answer

Tighten the bolts in a star or crisscross pattern using multiple, incremental steps of increasing torque.

Answer

Tighten the bolts sequentially in a clockwise pattern to the final torque value in a single pass.

Answer

Tighten the bolts in a star or crisscross pattern, applying the final torque in one continuous step.

Answer

Tighten the bolts to a snug-tight condition, then apply the final torque to every other bolt.

Question 2

Which of the following joining methods is most suitable for connecting small-bore (≤ 2 inches) carbon steel piping in a high-pressure hydraulic system where frequent disassembly is NOT required?

Accepted Answer

Socket weld

Answer

Threaded joint

Answer

Flanged joint

Answer

Grooved joint

Question 3

A pipefitter needs to create a 4-inch branch connection on a 10-inch header pipe that is currently in service and cannot be shut down. Which fabrication technique is specifically designed for this scenario?

Accepted Answer

Hot tapping

Answer

Stub-in branch welding

Answer

Using a butt-weld tee

Answer

Cold cutting and coupling

Question 4

According to ASME B31.3, when a branch connection is made by welding a fitting (like a Weldolet) onto a header pipe, what is the primary purpose of the fitting's design?

Accepted Answer

To provide integral reinforcement for the opening cut in the header pipe.

Answer

To provide a threaded outlet for instrumentation.

Answer

To reduce the flow velocity into the branch.

Answer

To transition between two different pipe schedules.

Question 5

A welding procedure specification (WPS) calls for a butt weld on a 6-inch carbon steel pipe to be made in the 6G position. What does this position entail?

Accepted Answer

The pipe is fixed at a 45-degree angle, and the welder must weld all around it without moving the pipe.

Answer

The pipe is in a vertical position, and the welder moves horizontally around it.

Answer

The pipe is in a horizontal position and is rolled as the welder applies the weld from the top.

Answer

The pipe is fixed in a horizontal position, and the welder must weld in flat, vertical, and overhead positions.

Question 6

When fabricating a piping system with polyvinyl chloride (PVC) pipe, what is the most common and recommended method for creating a permanent joint?

Accepted Answer

Solvent cementing

Answer

Butt fusion

Answer

Threaded connection with sealant

Answer

Compression fitting