Practice Test Geeks(SPED) Society of Piping Engineers and Designers Certification Practice Test
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Fluid Dynamics & Flow Analysis 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.

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  1. In gas pipeline design, the Weymouth equation is most accurate for:

    Answer: High-pressure, large-diameter, long gas transmission lines

    The Weymouth equation is empirically developed for high-pressure gas transmission pipelines and assumes fully turbulent flow.

  2. Choked flow in a gas line occurs when the gas velocity at the restriction reaches:

    Answer: The local speed of sound (Mach 1)

    Choked (critical) flow occurs when gas velocity reaches Mach 1 at the minimum cross-section; further reducing downstream pressure cannot increase mass flow.

  3. The equivalent length method for minor losses converts a fitting's resistance into:

    Answer: A length of straight pipe with the same frictional pressure drop

    The equivalent length Le expresses a fitting's pressure loss as the length of straight pipe that would produce identical friction loss, so Le = K·D/f.

  4. Flashing in a liquid piping system occurs when:

    Answer: Static pressure drops below the fluid's vapor pressure

    Flashing occurs when local static pressure falls below the saturation (vapor) pressure, causing partial vaporization of the liquid.

  5. For a gas flowing through a pipe, the Panhandle A equation accounts for which factor that Weymouth does not explicitly include?

    Answer: Pipe roughness effects at lower Reynolds numbers

    The Panhandle A equation was developed for partially turbulent flow regimes and includes an efficiency factor that implicitly accounts for friction variation with Reynolds number.

  6. The velocity of a pressure wave traveling through a liquid-filled pipe (wave speed 'a') is most significantly reduced by:

    Answer: Pipe wall elasticity and larger diameter-to-thickness ratio

    Wave speed a = √(K/ρ · 1/(1 + KD/Ee)), so higher pipe compliance (larger D/t or lower elastic modulus E) significantly reduces the wave propagation speed.

  7. The Strouhal number in vortex-induced vibration (VIV) of piping relates:

    Answer: Vortex shedding frequency, flow velocity, and pipe diameter

    Strouhal number St = fD/V relates vortex shedding frequency f, pipe diameter D, and flow velocity V; for circular cylinders St ≈ 0.2.