Questão 1
Questão
If properly designed, a closed-loop hydronic system should rid itself of most air within a few days of initial start-up.
Questão 2
Questão
The oxygen that causes corrosion is the same oxygen that forms water molecules.
Questão 3
Questão
Circulators transfer maximum head energy to incompressible fluids (e.g., liquids). A mixture of water and air is an example of an incompressible fluid.
Questão 4
Questão
Air has much lower specific heat and density than water.
Questão 5
Questão
Circulators with internal spring-load check valves installed in vertical piping with upward flow are especially susceptible to air pockets.
Questão 6
Questão
Although water may appear perfectly clear and free of bubbles, it can still contain a significant quantity of air in solution.
Questão 7
Questão
Combined air and dirt separators, or a hydraulic separator with the same capabilities, are never desirable in situations where an older distribution system containing steel or iron piping or radiators will be interfaced to a new boiler.
Questão 8
Questão
Properly designed and installed hydronic systems will always require constant manual air venting.
Questão 9
Questão
Low system pressurization is usually caused by not setting the make-up water system properly.
Questão 10
Questão
Glycol-based antifreezes tend to leave a slippery film on components and tools that eventually turn sticky.
Questão 11
Questão
Flow noise is generated when dissolved gases are released from improperly deaerated fluid due to a __________ in pressure.
Responda
-
increase
-
modulation
-
equalization
-
reduction
Questão 12
Questão
Air contains oxygen, and oxygen in contact with ferrous metals creates __________.
Responda
-
oxides
-
antigens
-
bubbles
-
deaeration
Questão 13
Questão
A large pocket of air trapped within a system can totally stop flow. This effect is often called air _________.
Responda
-
blockage
-
plugging
-
binding
-
trapping
Questão 14
Questão
Dissolved air can also lead to gaseous cavitation. Gaseous cavitation occurs when the pressure on the fluid __________ the saturation pressure of the dissolved gases it contains.
Responda
-
equals
-
drops below
-
rises above
-
is double
Questão 15
Questão
When air exists as bubbles, a moving fluid may be able to carry them along through the system. This is called __________ air.
Responda
-
entrained
-
fluid
-
deaerated
-
bubbly
Questão 16
Questão
The air removal devices used in small hydronic systems can be classified as either high point vents or __________.
Responda
-
"bleeders"
-
central air separators
-
"coin vents"
-
deaerators
Questão 17
Questão
The need for fully automatic (unattended) venting in locations not easily accessed requires a different type of device. A(n) __________ air vent often provided the solution.
Responda
-
electronic
-
top-loaded
-
ergonomic
-
float-type
Questão 18
Questão
A(n) __________ is capable of maintaining the system fluid in an unsaturated state of air solubility. This means that the water is always ready to absorb additional air from any areas of the system where it may be present.
Questão 19
Questão
A device that makes short work out of filling and purging residential and light commercial hydronic systems consists of a minimum 1-horsepower swimming pool pump mounted on a 30-gallon plastic trash barrel. This device is called a(n) __________.
Responda
-
circulator
-
purge cart
-
air scooper
-
deaerator
Questão 20
Questão
An automatic fluid feeder uses a small positive displacement pump operated by a pressure sensing switch to automatically pump fluid into the system when the pressure __________ a set minimum value.
Responda
-
reaches
-
drops below
-
exceeds
-
is stored at