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| There are two primary ways a shaft seals on centrifugal pumps are made. One method uses packing rings, the other uses? |
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Definition
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Term
| The sections in a boiler have water inside of them and _______ outside of them. |
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Definition
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Term
| A "packaged" boiler is usually shipped with____ installed on it |
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Definition
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Term
| The pressure reducing valve (PRV) installed on the make-up water line on a boiler comes factory set at ____psig but its normally adjustable |
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Definition
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Term
| The style of boiler which has the assembled boiler block sitting on top of a metal base is called____ a boiler |
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Definition
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Term
| A hydronic system which has multiple zones supplied by a single pump works best if the pump used has what? |
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Definition
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Term
| The style of pressure reducing valve (PRV) discussed in class has a lever type handle on it which is used to____? |
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Definition
| override the pressure setting to aid filling and air purging |
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Term
| The boiler rating number that relates to the amount of fuel consumed by a boiler during burner operation is the_____rating? |
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Definition
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Term
| The diaphragm style expansion tanks used on hydronic systems come factory pre-charged with____psgi of air pressure in them. |
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Definition
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Term
| You need to exercise caution when brushing out the flue passages of a boiler because? |
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Definition
| you could damage the combustion chamber liner. |
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Term
| How many sections would the smallest sectional boiler be built with? |
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Definition
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Term
| The style of boiler in which the sections have water in them all the way down to the floor is called a______boiler? |
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Definition
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Term
| The shortcut way to determine the volume of water that needs to be circulated thru the living space is to divide the Btus required by____? |
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Definition
temp difference X 500
Or
temp diff X 10,000 |
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Term
| If we need to supply 29,500 Btus of heat a space each hour, and the temp drop thru the system is assumed to be 15 degrees F, how many gallons of water does the pump have to move each minute (GPM) |
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Definition
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Term
| Pump performance curves show the performance of a pump using two criteria. they are head, and_____? |
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Definition
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Term
| If the expansion tank on a hydronic system gets "water logged", what systems would you likely see? |
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Definition
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Term
| What is the primary difference between a hydronic system which heats a building using steam and one which uses hot water? |
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Definition
| Heating points (ST-2120, HWB-180-2000), Accessories-HWB requires more parts (such as pumps, flow check valves, circulators and expansion tanks. Water levels-HWB is full and uses pump to circulate, ST is not fall and expands naturally to fill pipes. Efficiency and safety- HWB are considered safer than ST, ST are also less efficient because that don’t uses pumps, Costs-relatively the same. |
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Term
| Many people state that hydronic heating systems provide a greater level of occupant comfort due to the fact they supply most of their heat in the form of radiant heat. Why would this be true? |
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Definition
| Hydronic systems heat the objects and structure, NOT the air. Makes everything more comfotable for the occupants |
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Term
| TRUE or FALSE: the height of the column of water above the level of the connection point for the hydronic expansion tank on a boiler has no bearing on the air pressure required in the tank. |
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Definition
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Term
| Should a hydronic system which uses a plain steel (compression) tank for expansion have automatic air vents installed on it? |
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Definition
| NO, over time the air in the tank would escape out of the vent leaving it water logged |
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Term
| Why do boiler manufacturers cast all those little "fingers" into the sides of the flue passages on cast iron boilers anyway? |
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Definition
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Term
| For decades, what has been the most common material from which boiler sections have been built? |
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Definition
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Term
| If water is being discharged from the pressure relief valve on a boiler, what is one of the possible reasons? |
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Definition
| Hole in the diaphragm, water logged |
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Term
| What is one of the problems which is caused by air in a hydronic system? |
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Definition
| Cavitation/pitting, noise |
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Term
| By code, a boiler has to have a backflow preventor which is a "dual-check with an atmospheric _____ installed on it. |
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Definition
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Term
| What would determine if the backflow preventer on a boiler had to be upgraded to an RPZ (Reduced Pressure Zone) style |
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Definition
| If chemicals were added to the system (glycol) |
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Term
| The pressure relief valve that is used on a residential, hot water boiler is set to open at ____psig |
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Definition
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Term
| Some valves on a hydronic system are only there as "service" vales. A Globe valve is not a good choice for use as a service valve. Why not? |
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Definition
| because its a directional valve which causes a drop in pressure |
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Term
| What is the max number of 24 volt zone valves which should be connected to a 40V A transformer? |
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Definition
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Term
| Hydronic baseboard is rated by ______ per foot of element at a given water temp. |
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Definition
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Term
| Radiant panel (in-floor) heating systems will usually have a mixing valve and pump which feeds the in-floor loops. why is a mixing valve needed? |
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Definition
| Keeps the temp of the water more constant |
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Term
| The end switch on a zone valve gets connected to the? |
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Definition
| T-T terminals on the aquastat |
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Term
| Most of the zone valves used in a hydronic heating systems are normally ___ when the thermostat connected to them not calling for heat |
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Definition
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Term
| the force that opens a heat motor style zone valve is_____? |
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Definition
| hydronic force pushing the stem down |
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Term
| A ball valve which has a passage thru it that is almost as large as the diameter of the piping connected to it is called_____ball valve. |
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Definition
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Term
| If you were told that a valve had a Cv rating of 4.5, it would mean that |
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Definition
| 4.5 GPM of flow would produce 1 pound of pressure drop |
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Term
| There is a non-electric zone valve called _____ valve which is used to regulate the water flow to a radiator or baseboard. |
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Definition
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Term
| Erie and Honeywell both make 4-wire zone valves. Two of the wires are connected to the end switch in the valve, the other two are connected to the ____ in the valve |
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Definition
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Term
| The most common size valves sold are ___ pipe size because that's also the most common size baseboard. |
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Definition
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Term
| the two most common ways to zone a hydronic system are: one pump and a zone valve on each zone, or?? |
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Definition
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Term
| One of the main drawbacks to a series loop piping arrangement for radiation is that____? |
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Definition
| the water temp drop thru the loop can be significant |
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Term
| The max Btu load recommended for a 3/4 inch basboard loop is__ Btus per hour |
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Definition
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Term
| If one zone of a zoned system required 27,000 Btus of heat/hr, the amount of water that would need to circulate thru that zone would be (about) ____ GPM |
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Definition
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Term
| Two-pipe systems for connecting hydronic heating are classified as direct return or____? |
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Definition
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Term
| If a section of radiation is located below the piping main or the radiation has a lot of resistance, a Mono Flo system |
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Definition
| will require a Mono Flo tee on both risers |
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Term
| The performance of a hydronic circulator can be greatly improved by ___ |
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Definition
| piping it so that it pumps away from the expansion tank |
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Term
| if "cool" water flows back to the return of a cast iron boiler for an extended period of time, the sections can be damaged by |
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Definition
| condensation in the flue passages |
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