Piping Components 4 — Questions and Answers
Question 1: Which component is used to absorb thermal expansion and contraction in piping systems?
- A union fitting
- An expansion joint or expansion loop (Correct answer)
- A reducing coupling
- A street elbow
Correct answer: An expansion joint or expansion loop
Expansion joints and expansion loops are specifically designed to absorb the movement caused by thermal expansion and contraction in piping.
Question 2: What is a 'weld-o-let' used for in industrial piping?
- To weld two pipes together end to end
- To create a branch connection by welding directly to the run pipe (Correct answer)
- To cap the end of a high-pressure pipe
- To connect flanged components without bolts
Correct answer: To create a branch connection by welding directly to the run pipe
A weld-o-let (olet fitting) is welded directly onto the run pipe to create a reinforced branch outlet connection.
Question 3: What is the purpose of a strainer (Y-strainer) in a piping system?
- To regulate fluid flow velocity
- To remove solid particles and debris from the fluid stream (Correct answer)
- To allow fluid to flow in one direction only
- To reduce pipe diameter gradually
Correct answer: To remove solid particles and debris from the fluid stream
A Y-strainer uses a perforated or mesh screen to filter out solid particles and protect downstream equipment from damage.
Question 4: In which situation would you use an eccentric reducer rather than a concentric reducer?
- When connecting pipes of the same diameter
- When installing horizontal liquid lines to prevent air pockets or vapor locks (Correct answer)
- When working with high-pressure steam systems
- When connecting threaded fittings to welded pipe
Correct answer: When installing horizontal liquid lines to prevent air pockets or vapor locks
Eccentric reducers are used in horizontal liquid lines with the flat side up to prevent air pockets, or flat side down to avoid sediment traps.
Question 5: What is a 'flange' in piping, and what is its primary advantage?
- A type of valve that controls flow rate with a disc
- A flat ring fitting that bolts two pipe sections together, allowing easy disassembly (Correct answer)
- A fitting used to join pipes of different materials without welding
- A pressure relief device installed on high-pressure lines
Correct answer: A flat ring fitting that bolts two pipe sections together, allowing easy disassembly
A flange is a flat disc-like fitting bolted to another flange to join pipe sections, allowing easy disassembly for maintenance or inspection.
Question 6: What does 'Schedule' refer to when describing pipe components?
- The length of pipe sections in a run
- The wall thickness of the pipe relative to its outside diameter (Correct answer)
- The material grade of the pipe or fitting
- The pressure rating of fittings in a system
Correct answer: The wall thickness of the pipe relative to its outside diameter
Pipe schedule designates wall thickness — a higher schedule number means a thicker wall, which supports higher pressure ratings.
Question 7: Which type of valve is best suited for fully open or fully closed service and should NOT be used for throttling?
- Globe valve
- Gate valve (Correct answer)
- Needle valve
- Pressure regulating valve
Correct answer: Gate valve
Gate valves are designed for on/off service and should not be used for throttling because partial opening causes erosion and chattering of the gate.
Piping Components 4
Which component is used to absorb thermal expansion and contraction in piping systems?