Steamfitter Key Skills and Knowledge Areas 2 — Questions and Answers
Question 1: What type of weld joint is most commonly used when joining two pipes end-to-end in a high-pressure steam system?
- Socket weld
- Butt weld (Correct answer)
- Fillet weld
- Lap weld
Correct answer: Butt weld
Butt welds are preferred for high-pressure piping because they provide full penetration and maximum joint strength.
Question 2: Which tool is used to verify that a pipe flange face is perfectly flat before assembly?
- Pipe level
- Straight edge and feeler gauge (Correct answer)
- Caliper
- Pipe wrench
Correct answer: Straight edge and feeler gauge
A straight edge and feeler gauge are used together to detect any high or low spots on a flange face.
Question 3: When installing expansion loops in a steam piping system, what is the primary purpose?
- To reduce flow velocity
- To allow for thermal expansion and contraction (Correct answer)
- To increase system pressure
- To filter condensate
Correct answer: To allow for thermal expansion and contraction
Expansion loops absorb the dimensional changes in pipe length caused by heating and cooling cycles.
Question 4: A steamfitter discovers a threaded fitting is leaking at a joint. What is the correct first step before re-making the joint?
- Apply more pipe dope over the existing joint
- De-pressurize and drain the system (Correct answer)
- Tighten the fitting with a pipe wrench while under pressure
- Wrap the joint with tape and continue
Correct answer: De-pressurize and drain the system
Safety requires the system to be de-pressurized and drained before any threaded joint is disassembled or repaired.
Question 5: Which piping material is NOT acceptable for use in high-pressure steam service above 250 psi?
- Carbon steel (Schedule 80)
- Stainless steel
- Cast iron (Correct answer)
- Chrome-moly alloy steel
Correct answer: Cast iron
Cast iron is brittle and cannot safely handle the thermal cycling and pressure demands of high-pressure steam service.
Question 6: What does the term 'pipe schedule' refer to?
- The installation timeline for a piping project
- The wall thickness of a pipe relative to its nominal diameter (Correct answer)
- The pressure rating of a pipe fitting
- The material grade of the pipe
Correct answer: The wall thickness of a pipe relative to its nominal diameter
Pipe schedule is a standardized designation that defines wall thickness; higher schedule numbers indicate thicker walls.
Question 7: When reading an isometric drawing, what do the small 'tick' marks on a pipe run typically indicate?
- Weld locations (Correct answer)
- Change of pipe size
- Insulation boundaries
- Flow direction
Correct answer: Weld locations
Tick marks on isometric pipe drawings are used to indicate the location of field welds.
Steamfitter Key Skills and Knowledge Areas 2
What type of weld joint is most commonly used when joining two pipes end-to-end in a high-pressure steam system?