Piping Engineering 2 — Questions and Answers
Question 1: What is the primary purpose of a pipe stress analysis in piping engineering?
- To determine pipe wall thickness
- To evaluate forces and moments on piping systems under load (Correct answer)
- To calculate fluid flow velocity
- To select pipe material grade
Correct answer: To evaluate forces and moments on piping systems under load
Pipe stress analysis evaluates forces, moments, and displacements in piping systems caused by pressure, temperature, weight, and other loads.
Question 2: Which piping code primarily governs process piping in industrial plants in the US?
- ASME B31.1
- ASME B31.3 (Correct answer)
- ASME B31.4
- ASME B31.8
Correct answer: ASME B31.3
ASME B31.3 covers process piping used in petroleum refineries, chemical plants, and similar facilities.
Question 3: What does the term 'schedule' refer to when specifying pipe?
- The delivery timeline for pipe
- The pipe wall thickness designation (Correct answer)
- The pipe length standard
- The allowable pressure rating
Correct answer: The pipe wall thickness designation
Pipe schedule is a dimensionless designator that determines the wall thickness of a pipe for a given nominal pipe size.
Question 4: What is cavitation in a piping system?
- Air trapped in a high point of pipe
- Formation and collapse of vapor bubbles due to pressure drop below vapor pressure (Correct answer)
- Erosion of pipe from abrasive particles
- Thermal expansion of liquid in a closed system
Correct answer: Formation and collapse of vapor bubbles due to pressure drop below vapor pressure
Cavitation occurs when local pressure drops below the fluid's vapor pressure, forming bubbles that collapse violently and damage equipment.
Question 5: Which type of valve provides the best throttling control in a piping system?
- Gate valve
- Ball valve
- Globe valve (Correct answer)
- Butterfly valve
Correct answer: Globe valve
Globe valves are designed for throttling service because their disc movement perpendicular to the seat allows fine flow control.
Question 6: What is the purpose of a rupture disk in a piping system?
- To reduce flow turbulence
- To provide one-time overpressure protection by bursting at a set pressure (Correct answer)
- To measure differential pressure
- To prevent backflow in the line
Correct answer: To provide one-time overpressure protection by bursting at a set pressure
A rupture disk is a non-reclosing pressure relief device that bursts at a predetermined pressure to protect equipment from overpressure.
Question 7: In piping design, what is the term for the minimum pressure a piping system must withstand at maximum operating temperature?
- Design pressure (Correct answer)
- Operating pressure
- Test pressure
- Burst pressure
Correct answer: Design pressure
Design pressure is the maximum internal pressure used in the design of a piping component, typically set above the maximum expected operating pressure.
Piping Engineering 2
What is the primary purpose of a pipe stress analysis in piping engineering?