Hydronics
What are BTU's?
(pounds of water) x (specific heat) x (temperature difference) = BTU;s
What is the string equation?
1 psi= 16 oz/in = 27.72 wc = 2.036 Hg = 6.895 kPA = 2.31 HD
What is MBH
1000BTU/Hr
Steel boilers may operate up to what pressure?
116 psi
What is the operating pressure of most domestic boiler PRV's?
12 psig
A cubic foot
12"x12"x12" = 1728 inces (volume=heightxwidthxdepth) 12"12" = 144 square inches (area=widthxdepth)
What is atmospheric pressure at sea level?
14.7 PSI. 13.65 in SK
What is the BTU equivalent of 1 Water EDR?
150 BTU
How much does steam volume increase?
1700 times
What is the BTU equivalent of 1 Steam EDR?
240 BTU
Low boilers operate under?
250 F
Cast iron heat exchangers are limited to what?
250F/120C and 30 PSIG
What is the minimum size of relief valve on a low pressure cast iron boiler?
3/4 inch
Low pressure boilers made of cast iron operate up to what pressure?
30 psi
What is the BTU equivalent of 1 Boiler Horspower? (BHP)
33 475 BTU
When is water at the maximum density?
4C
What is the latent heat of water vaporization?
970 BTU
Air scoop
A device installed in the hot water supply main at or near the heating source to separate and direct the air to a cushion tank or automatic air vent.
Aquastat
A device that measures the temperature of a liquid at some point in a system. Opens or closes electrical contacts based on that temperature and its set point temperature.
What control is required on copper tube or coil type heat exchangers and explain why.
A flow switch. So that water doesn't expand too much and flash into steam
Air handler
A generic name for a device consisting of a blower and a finned-tube coil. Used to heat or cool air based on the temp of the fluids passing through the coil.
Baseboard radiator
A heat emission unit located at the lower perimeter of a room.
Circulator
A pump
What does a condensing boiler employ?
A secondary heat exchanger to condense the flue gas water vapor
Ball valve
A valve containing a rotating ball with a hole through it
Balancing valve
A valve operated at a partially open setting ti achieve a desired rate or pressure drop at a given location in a hydronic system.
Angle valve
A valve with its outlet port rotated at 90 degrees from its inlet port
Capilllary Tube
A very small diameter tube between a temperature sensing bulb and a controller
Convection
A way that heat is transferred through a liquid or gas
What is the approval agency?
A.S.M.E.
Approved
Accepted by the enforcing authority
Automatic air vents
Air vents that can automatically eject air as it accumulates within them.`
A.S.T.M.
American Society for testing and Materials
A.S.M.E.
American Society of Mechanical Engineers
Alkalinity
Amount of carbonates, bicarbonates, hydroxides, and silicates or phosphates in the water.
Actuator
An electrically or pneumatically driven device that adjusts the position of a valve stem or damper based on the signal it receives from a controller.
What kind of operating control is found on a LTHW boiler?
Aquastat
What is at sea level?
Atmospheric pressure is 14.7 PSIA and at certain temperatures, water will change its state.
What are hybrid boilers designed for?
Being a space heater and a water heater
What happens when pressure increases?
Boiling point increases
C.G.A.
Canadian Gas Association
C.S.A.
Canadian Standards Association
Which boilers are high mass?
Cast iron sectional and fire tube
What are hot water boiler heat exchangers made of?
Cast iron, copper, or steel
Air supply
Combustion air
Which boilers are low mass?
Copper and steel tube boilers
What is the government branch that regulates Boilers and Pressure Vessels in Saskatchewan?
Corrections and Public Safety
Corrosion
Destruction of metal by electro-chemical reaction from environment
What are the parts of a boiler?
Draft hood, vent connector, water inlet, products of combustion, jacket, insulation, heat exchanger, dilution air, water outlet
What would change a gravity heat system into a closed system?
Expansion tank
What type of heaters do swimming pools use?
Fin tube boilers
Name two ways to stop the migration of heat from the boiler heat exchanger
Flow control valve and an insulated jacket
What safety control is required on a copper fin tube boiler?
Flow switch
Combination Gauge
Gauge that measures pressure and temperature
Compound Gauge
Gauge used to indicate vacuum and pressure
Control Valve
Globe valve used to control flow of liquid or gas
What is the Net Rating of a boiler?
Gross Output - System Losses=Net Rating
What is the chemical symbol for water?
H20
Cast iron sectional boilers are?
High mass
Fire tube boilers are?
High mass
Fin tube boilers are available as what?
Hot water boilers only
What does a boiler's fuel consumption determine?
Input rating
To stop heat loss from boilers what do you do to the pipes?
Insulate them
Fine tube boilers are?
Low mass
Steel tube boilers are?
Low mass
When the boiler is above the lowest piping in the system, what safety device is needed?
Low water cutoff
Is it easier to maintain high energy or continually accelerate and decelerate?
Maintain high energy
Air vent
Manual or automatic device that releases air bubbles from a piping system
What type of control is the gas valve of a boiler?
Modulating gas valve
What device is used to reduce city pressure to a desirable working pressure in the hydronic system?
PRV
Backflow preventer
Piping component that contains the functional equivalent of two check valves and a vent port.
Boiler Trim
Piping on or near the boiler that is used for safety, limit, operating, gauges, water column, etc.
Closed-loop System
Piping system that is sealed at all points
What must each modular boiler have?
Pressure gauge, thermometer, temperature limit control, safety relief valve, and a drain valve
Absolute Pressure
Pressure of a liquid or gas relative to a perfect vacuum.
Air-side pressurization
Pressure on the air side of a diaphragm-type expansion tank before fluid enters the tank.
What are water tube boilers?
Quick recovery and low mass
What control senses the maximum allowable temp of the boiler water?
Safety limit control
What type of high limit control is found on a LTHW boiler?
Safety relief valve
Fire tube boilers include what?
Scotch Marine Boilers and Horizontal Return Tube Boilers
What section of the B149.1 Natural Gas and Propane Installation Code does an installer need to refer to for appliance clearances to combustibles?
Section 7
What are boilers initially rated by?
Square feet of heating surface
What is the Gross Output Rating of a boiler?
Stack/Jacket Losses - Input=Gross Output
What temperatures does water change state?
Steam at 212F (100C) and change to ice at 32F(0C)
What two things change water density?
Temperature and pressure
Ambient temperature
Temperature in the air surrounding the equipment.
Acidity (boiler water)
The amount of free carbon dioxide, mineral acids and salts which hydrolyze to give hydrogen ion in water.
Where is the combustion chamber in a wetbase boiler?
The bottom of the boiler sections
Cavitation
The formation of vapor pockets when the pressure on a liquid drops below its vapor pressure
Air binding
The inability of a circulator to dislodge a large air pocket at a high point in the piping system.
Allowable working pressure
The maximum pressure for which the boiler was designed and constructed.
The determining factor for the boiler net output would be what?
The system heat loss
How does a gravity heat system work?
Thermal convection
Why must water continuously flow in finned tube boilers?
To prevent the water from flashing to steam inside the heat exchanger
Closely Spaced Tees
Two tees that are installed right beside each other
U.L.C.
Underwriters Laboratories of Canada
Name two configurations of cast iron boilers
Vertical and horizontal
What are the two bases of boilers?
Wetbase and drybase
When are electrical boilers used?
When gas isn't available. They must meet the standards of all other boilers.
How is a horizontal sectional boiler constructed?
With the sections stacked on top of one another (like pancakes)