Pipefitter Core Responsibilities 4 — Questions and Answers
Question 1: When a pipefitter discovers an unmarked underground utility line during excavation, what is the correct immediate action?
- Continue digging carefully to identify the line
- Stop work and notify the supervisor and utility owner (Correct answer)
- Mark the line and proceed with the job
- Remove the line if it interferes with the pipe route
Correct answer: Stop work and notify the supervisor and utility owner
Work must stop immediately and the supervisor and utility owner must be notified to prevent damage or injury.
Question 2: Which document governs the allowable pressure rating for a piping system in a given facility?
- The purchase order for the pipe material
- The piping and instrumentation diagram (P&ID)
- The piping specification or pipe class document (Correct answer)
- The contractor's work order
Correct answer: The piping specification or pipe class document
The piping specification or pipe class document defines materials, pressure ratings, and fittings allowed for each service.
Question 3: A pipefitter is asked to install a branch connection on a high-pressure steam header. Which method is MOST appropriate for a full-strength connection?
- Threadolet fitting welded to the header (Correct answer)
- Saddle weld directly onto the pipe wall
- Threaded nipple screwed into a drilled hole
- Compression fitting clamped to the outside
Correct answer: Threadolet fitting welded to the header
A threadolet (or weldolet) provides a full-penetration weld and is rated for high-pressure branch connections.
Question 4: What is the primary purpose of a hydrostatic pressure test on a newly installed piping system?
- To clean the interior of the pipe before commissioning
- To verify the system holds pressure without leaks or failures (Correct answer)
- To check the alignment of pipe supports
- To flush debris from the pipeline
Correct answer: To verify the system holds pressure without leaks or failures
A hydrostatic test confirms the integrity of all welds, fittings, and joints by pressurizing the system above operating pressure.
Question 5: Which OSHA standard primarily governs permit-required confined space entry for pipefitters?
- 29 CFR 1910.119
- 29 CFR 1910.146 (Correct answer)
- 29 CFR 1926.502
- 29 CFR 1910.217
Correct answer: 29 CFR 1910.146
29 CFR 1910.146 covers permit-required confined spaces, including atmospheric testing and entry procedures.
Question 6: What does the term 'dead leg' refer to in a process piping system?
- A pipe section with no flow that can accumulate contamination or stagnant fluid (Correct answer)
- A pipe run that bypasses a control valve
- A support leg under a horizontal pipe section
- A blind flange installed at a system terminus
Correct answer: A pipe section with no flow that can accumulate contamination or stagnant fluid
A dead leg is a section of piping with no flow, which can lead to corrosion, contamination, or freezing in certain services.
Question 7: Before beginning hot work (welding/cutting) on a piping system in a plant, a pipefitter must first obtain a:
- Material safety data sheet for the pipe material
- Hot work permit signed by the area authority (Correct answer)
- Written request from the pipe owner
- Approval from the welding inspector only
Correct answer: Hot work permit signed by the area authority
A hot work permit ensures hazards are identified, combustibles are cleared, and fire watch is in place before ignition sources are introduced.
Pipefitter Core Responsibilities 4
When a pipefitter discovers an unmarked underground utility line during excavation, what is the correct immediate action?