Water Properties and Systems Quiz

Properties of Water

• Specific gravity of water is assumed to be 1.0, allowing it to float on pure water.
• Substances with specific gravity greater than 1.0 are denser than water and will sink.

Fundamental Units of Water Systems

• Volume (V): Amount of space occupied by a substance, often measured in gallons (g or gal).
• 1 cubic foot (ft³) equals 7.48 gallons; 1 gallon is approximately 3.8 liters.
• Volumetric Flow Rate (Q): Volume passing a point per time, calculated as ( Q = \frac{Volume}{time} ) (commonly in m³/s or gpm).
• Velocity (v): Rate of linear motion; average velocity of water is used due to varying speeds of water molecules.
• Pressure (P): Force per unit area from a liquid or gas; commonly measured in pounds per square inch (psi).
• Standard atmospheric pressure is approximately 14.696 psi at sea level (101,325 Pa).

Domestic Water Supply Systems

• Building Main: Primary water supply pipe running through the building, often located in basements or ceilings.
• Riser: Vertical pipe extending at least one story, connecting to fixture branches to supply water to fixtures.
• Fixture Branch: Pipe that runs from the riser or main to individual fixtures, either in walls or floors.
• Fixture Connection: Pipe connecting the fixture branch to the fixture, usually including a shut-off valve.

General Water Distribution System

• Water Service Pipe: Underground pipe (lateral) delivering pressurized potable water from the street main to the building.
• Water Meter: Device measuring consumption connected to the water service lateral.

Water Supply Considerations

• Potable Water: Clean water suitable for drinking, cooking, and cleaning; vital for human survival.
• Nonpotable Water: Water unsuitable for drinking (e.g., used for flushing toilets, irrigation).
• Surface Water: Freshwater found in rivers, lakes, swamps, and reservoirs; does not infiltrate to become groundwater.
• Groundwater: Water trapped in sediment and rock; can be accessed from various depths through aquifers.
• Aquifers and Wells: Layers of groundwater; artesian wells force groundwater to the surface.

Water Collection and Treatment

• Watershed: Land area where water flows towards a common body, consisting of tributaries leading to larger bodies of water.
• Reservoirs: Hold surface water for use during periods of high runoff; treated to provide potable water.
• Cistern: Storage tank collecting rainwater, typically from roofs, that is pumped into building supply lines.

Water Pressure Dynamics

• Hydrostatic Pressure: Force exerted by fluid weight against container walls; pressure is directly proportional to fluid depth.
• Pressure loss in plumbing systems occurs due to friction and changes in elevation.
• Acceptable water pressure at service points ranges from 40 to 80 psi (275 to 550 kPa); pressure drops are common as water moves through pipes.
• Minimum pressure requirements for plumbing fixtures are specified by code, typically requiring 8 psi (55 kPa) for flush tanks.

Fluid Flow Principles

• Fluid flows from regions of higher pressure to lower pressure, driven by pressure differences.