Introduction to Ship Building Piping

A: Heating reduces viscosity and frictional losses, improving valve control; density effects don't dominate here, Reynolds number actually rises not falls, and vapor lock isn't driven by moderate HFO heating at service tank pressures.

A: Poor venting traps air at high points during idle periods; impeller wear wouldn't self-recover after venting, check valve flutter doesn't create persistent air pockets, and strainer fouling causes sustained loss not intermittent prime loss.

A: Epoxy-lined carbon steel addresses condensate-driven corrosion; aluminum suffers pitting and fatigue issues, 316L is overkill and still vulnerable to crevice attack at drains, and bare steel relies on maintenance that rarely matches reality.

A: Hydraulic losses from long, small branches explain local low pressure with normal pump discharge; pump wear or air ingress would affect all hydrants, and gauge range errors don't change delivered flow.

A: Suction throttling reduces NPSHa and promotes cavitation; cold water doesn't negate vapor pressure limits, reduced velocity doesn't compensate for pressure loss, and efficiency doesn't recover lost suction head.

A: Unbraced small-bore take-offs experience cyclic vibration leading to fatigue; overpressure would cause yielding not cracks, material defects wouldn't localize at clamps, and thermal mismatch shows slow distortion not high-cycle failure.

A: Polypropylene resists chemicals and avoids corrosion; carbon steel degrades quickly in grey water, copper reacts with cleaning agents, and cast iron coatings fail at joints over time.

A: Lower pressure promotes flashing and two-phase instability; heat loss isn't the driver, density doesn't increase here, and subcooling won't occur without pressure or temperature change.

A: Poor slope traps air reducing local flow despite normal pressure; low viscosity would show system-wide effects, a stuck relief lowers discharge pressure, and transmitter drift doesn't overheat bearings.