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CAPTER 8. Plumbing Equipment and System 8.3
What are there equivalent between pound and
grain, gallons and cubic feet, ppm and
mg/L? ? ? ppm and mg/L
8.5 Name seven process processes used to improve
the quality of water. ? Sedimentation,
Coagulation ,Aeration ,Filtration ,Disinfection
,Fluoridation ,Softening 8.7 What mineral
content is used determine the hardness in water?
? Carbonate or CaCO3 8.9 What is osmosis?
What is reverse osmosis? ? OsmosisThe
phenomenon of water flow through a semi-permeable
membrane that blocks the transport of salts or
other solutes through it. Osmosis is a
fundamental effect in all biological systems. It
is applied to water purification and
desalination, waste material treatment, and many
other chemical and biochemical laboratory and
industrial processes. ? Reverse
osmosisThe process of forcing a solvent from a
region of high solute concentration through a
semipermeable membrane to a region of low solute
concentration by applying a pressure in excess of
the osmotic pressure.
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8.19 What is the function of a vacuum break?
? An attachment commonly placed on a bibcock
valve or toilet or urinal flush valve, that
prevents water from being siphoned backward into
the public water system. This prevents
contamination should the public water system's
pressure drop. 8.21 What is the function of a
shock absorber? Where should it be installed?
? When the flow of water in a pipe is a abruptly
stopped, as by the closing of a faucet or a
flushometer, the dynamic (kinetic)energy in the
water must be absorbed 8.23 Why is a
flushometer, rather than flush tanks, required
for water closets in public facilities?
? A device for flushing toilets and urinals that
utilizes pressure from the water supply system
rather than the force of gravity to discharge
water into the bowl, designed to use less water
than conventional flush toilets. 8.25 What is
the purpose of a drainage trap? Do water closets
require traps? ? To prevent the backup
of sewer gas
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8.27 What is the difference between a waste pipe
and a soil pipe? ? waste pipe Pipes
which convey waste water from any or all of the
fixtures in a building except the water closets.
? soil pipe The pipe that directs the
sewage of a house to the receiving sewer,
building drain or building sewer. 8.31 What is a
stack? A vent? A stack vent? A vent stake?
? Stack vertical portion of a SWV-piping
system. ? vent Pipe open to the
atmosphere. ? vent stack Stack that
does not carry waste of any kind and that is
installed primarily for providing
circulation of air to and from any part of the
DWV system. ? stack vent Open-ended
extension of a water or soil stake above the
highest horizontal drain connected to the stack.
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8.35 Normally, municipalities in the Unite
States have separate sanitary sewer systems
however, several major cities still have
combination storm and sanitary sewer systems. In
such cases, can the sanitary and storm piping
systems within the building be combines?
? The sanitary and storm water systems can be
combined either inside or outside the building
wall. But good engineering practice has them
leave the building separately and combined
outside the building wall(Facility piping systems
Handbook, second edition, Michael Frankel, 2001,
pp 9.45). ? But, in the south Korea,
Separation of sanitary and storm sewer systems is
decided by building law(Section 17(5) of building
equipment standard). 8.39 What is the purpose of
a dosing chamber in a septic tank sewage
treatment systems? ? Component of the
septic tank system that periodically discharges
effluent to an approved method of disposal.
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8.1.2 Processes Commonly Used to Improve Water
Quality

• Sedimentation Suspended matter by
  precipitation Reduces the turbidity
• Coagulation
• Use chemicals(hydrated aluminum sulfate)
• Reduce turbidity and improve the color and taste
  of water
• Aeration
• Air into water to oxidize impurities to improve
  the color and taste
• Filtration
• Removes suspended material and bacteria
• Improve overall quality (turbidity, potability,
  color and taste)
• Disinfection
• Use chlorine gas, hypochlorite solid,
  ultraviolet light to disinfect bacteria
• Fluoridation
• Adds a fluoride chemical in water to prevent
  tooth decay
• Softening
• Replaces Ca and Ma ions with Na ions to reduce
  scale formation

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• Water Purification System
• A deionizing system the tank contain a mixed
  bed of both cation- and anion-absorbing resins
  made of porous polymer minerals
• A reverse osmosis(RO) , Distillation

Operating principle of a mixed-bed deionizer
Principle of (a) osmosis (b) reverse osmosis
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8.2.4 Design Considerations for Water
distribution Systems

• Vacuum breaker is installed at the branch
  connection to an equipment item or plumbing
  fixture, such as a sink, dishwasher, boiler,
  water closet, or urinal

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8.2.4 Design Considerations for Water
distribution Systems

• Shock Absorption
• when the flow of water in a pipe is a abruptly
  stopped, as by the closing of a faucet or a
  flushometer, the dynamic (kinetic)energy in the
  water must be absorbed
• if it is not, the energy will be converted into a
  loud noise and vibration known as water hammer.