SPED Piping Design Principles & Standards 4

Question 1

Which of the following is NOT a recognized type of pipe stress analysis per ASME B31.3?

Accepted Answer

Compressive buckling stress

Answer

ASME B31.3 categorizes pipe stresses as sustained (dead weight and pressure), occasional (wind, seismic), and expansion (thermal) loads; compressive buckling is not a defined B31.3 stress category.

Question 2

What is the purpose of a pipe rack in an industrial plant?

Accepted Answer

To provide an elevated structure that routes and supports multiple process piping runs

Answer

Pipe racks are structural frameworks that elevate and organize multiple piping runs across the plant, providing efficient routing between equipment while allowing maintenance access.

Question 3

In piping design, what does 'NPSH' refer to and why is it important?

Accepted Answer

Net Positive Suction Head — ensures adequate pressure at pump inlet to prevent cavitation

Answer

Net Positive Suction Head (NPSH) is the difference between suction pressure and fluid vapor pressure; insufficient NPSH causes cavitation, which damages pump impellers.

Question 4

Which insulation type is typically used for cryogenic piping operating below -100°F?

Accepted Answer

Cellular glass

Answer

Cellular glass insulation is preferred for cryogenic service because it is impermeable to moisture, dimensionally stable at low temperatures, and does not absorb condensation.

Question 5

What is a 'dead leg' in a piping system, and why is it a concern?

Accepted Answer

A stagnant section of piping with no flow, which can cause corrosion, contamination, or Legionella growth

Answer

Dead legs are sections of pipe with no flow where fluid stagnates, potentially causing microbial growth, corrosion, or product contamination — especially critical in pharmaceutical and water systems.

(SPED) Society of Piping Engineers and Designers Certification Practice Test

(SPED) Society of Piping Engineers and Designers Certification Practice Test

SPED Piping Design Principles & Standards 4