Stress Analysis & Mechanical Integrity Flashcards
7 cards from real SPED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Stress Analysis & Mechanical Integrity flashcards as text
In API 610 pump nozzle load evaluation, what does a 'load multiplier' greater than 1.0 signify?
Answer: The piping applies loads exceeding standard API 610 Table 4 allowables, requiring vendor approval
API 610 allows load multipliers when vendors confirm the pump can tolerate higher-than-standard nozzle loads, often through detailed FEA of the casing.
Which of the following most accurately describes 'creep' in high-temperature piping?
Answer: Time-dependent plastic deformation under sustained stress at elevated temperature
Creep is the slow, time-dependent deformation that occurs when metals are held under stress at temperatures above roughly 0.4 times the absolute melting point.
What is the purpose of performing a 'free-body diagram' analysis at an equipment nozzle?
Answer: To resolve all piping forces and moments acting on the nozzle for equipment evaluation
A free-body diagram isolates all forces and moments from the piping stress model at the nozzle node, providing the loads to be compared against equipment allowables.
Which ASME standard provides allowable nozzle loads for shell-and-tube heat exchangers?
Answer: TEMA (Thermal Equipment Manufacturers Association) standards
TEMA standards establish nozzle load allowables for shell-and-tube heat exchangers, which are used in conjunction with the stress analysis nozzle load outputs.
In a seismic stress analysis, the 'response spectrum method' accounts for:
Answer: The dynamic amplification of ground motion at various natural frequencies
The response spectrum method applies frequency-dependent earthquake excitation to determine the dynamic response of the piping at its various natural frequencies.
A piping engineer calculates the 'hot modulus of elasticity' (Eh) for a stress analysis. This value is used to:
Answer: Determine pipe stiffness at operating temperature for displacement stress calculations
The hot modulus (Eh) reflects the reduced stiffness of the pipe material at operating temperature and is used in computing displacement (thermal expansion) stresses.
Which parameter is most critical when checking a pipe span for excessive vibration susceptibility?
Answer: Natural frequency of the pipe span relative to excitation frequencies
If the natural frequency of a pipe span coincides with an excitation frequency (pump, compressor, flow pulsation), resonance can cause fatigue failure.