Learning tasks Flashcards
True or false: plumbers install water distribution systems
True
Define Service Water heater
a device for heating water for plumbing services
Who uses private water sources and where can they be found?
Rural
lakes and wells
What is a benefit in having a water meter?
can determine if there are any leaks or unauthorized use of water taking place
What are the 2 basic types of water meters?
positive displacement
velocity
Where are positive displacement meters used most?
residential (very accurate)
small commercial
What type of meter is sensitive to flow rates and have a high accuracy?
Positive displacement meters
What is the minimum size of water service that would require a bypass?
1 1/2” (40mm)
What is a Fixture supply pipe also called?
graded supply
What is a fixture supply pipe?
a pipe installed bn a fixture / another building water distribution pipe.
What is another name for a stop-and-drain?
stop-and-waste
What is the largest control valve with a drain?
1”
True or False: sprinklers are on a metered system.
False
Why are PRV installed?
to limit the max pressure to 550kPa (80psi)
Do fixture units for irrigation systems have to be added to the water service sizing?
Yes
What must be supplied in every dwelling and where WC and lavs are mandatory?
a hot water supply
Define a service water heater
is an expansive fluid and a device for heating water for plumbing services
Does direct heating have it’s own heat source?
Yes, uses combustion fuels
Does Indirect heating have its own heat source?
nope, gets its heat from remote heat services (boilers, solar etc)
What are point of distribution water heaters?
water heaters that serve the entire domestic hot water distribution system
What is a point of use water heater?
a water heater designed to deliver hot water almost instantaneously
Where are point-of-use water heaters installed?
location of the fixture
True or False: Indirect water heaters has its hot water from a heat source the flows through one side of a heat exchanger
True
Define indirect service water heater
a service water heater that gets its heat from a heating medium such as warm air, steam or hot water.
What does an anode rod do?
protect exposed steel areas against corrosion
What are anode rods made of?
either aluminum or magnesium
What is the purpose of a dip tube?
deliver cold water near the bottom of the tank
Where is a temperature and relief valve installed on all HWT?
12 inches from the floor
Where are point -of-use heaters aka booster heaters installed?
commercial dishwashers
What temperature do booster heaters boost it to?
180 F or 82 C
What is an advantage to electric water heaters?
They do not require a vent
can be installed in various locations
What is the efficiency of an electric water heater?
100%
what is the efficiency of a gas-fired tankless water heater?
80%
Why is storing hot water at temperatures below 60 C 140F not a good idea?
may lead to the growth of legionella bacteria
True or false: hot water delivered at 60 C (140 F) will severely burn human skin in 1 to 5 seconds
true
What do manufacturer’s water heating sizing calculations use?
a 2 hour window
What are 2 types of mixing valve design?
pressure - balanced and temperature activated (thermostatic)
What happen if hot water tanks are allowed to operate at excessively high pressures?
creates bursts of water / piping noise when a fixture is first opened
Where should the thermal expansion tank be placed?
always on the cold water piping supply
downstream of any non-return valve or device
How are circ pumps sized?
by height
What are compound meters?
Meters that feature both positive displacement and velocity (turbine)
