Working principles of flowmeters vs pressure measuring instruments:

• An Orificemeter measures flow rate by creating a differential pressure across a constriction based directly on Bernoulli's principle.
• Venturimeter accelerates fluid through a converging-diverging throat to convert pressure head to velocity head per Bernoulli's equation.
• Pitot tube measures fluid velocity by converting kinetic energy into stagnation pressure head per Bernoulli's equation.
• Bourdon tube is a mechanical pressure gauge that operates based on the elastic mechanical deflection/uncoiling of a flattened, curved metal tube subjected to internal static fluid pressure; it does not utilize fluid velocity or Bernoulli's hydrodynamic energy equation.

Fundamental laws of hydrostatics:

• Archimedes' principle governs buoyant upward force on submerged bodies.
• Bernoulli's principle relates pressure, velocity, and elevation along a streamline in moving fluids.
• Pascal's Law states that in a fluid at rest in a closed system, the pressure exerted at any point is transmitted equally and undiminished in all directions throughout the fluid ($P_x = P_y = P_z$).
• Continuity principle governs mass conservation in fluid conduits ($A_1 v_1 = A_2 v_2$).

Construction of centrifugal pumps:

• Pistons belong to reciprocating positive displacement pumps.
• The two vital working components of any centrifugal sanitary milk pump are the rotating Impeller (which imparts kinetic energy to the liquid) and the stationary Volute casing (a spiral expanding chamber that smoothly converts velocity head into pressure head).
• Diaphragms belong to diaphragm pumps.
• Gears belong to rotary gear pumps.