DC 3RD CLASS TEST (ACTUAL EXAM 2026) | 3RD CLASS
STATIONARY STEAM ENGINEER LICENSE PREP |
STATIONARY ENGINEER | STATION ENGINEER EXAM |
DC 1ST CLASS BOILER | JUST RELEASED
An air handler unit that has hot & cold air ducts connected to (molding
boxes?) located in each building space is called a __________air
handler unit? ---------CORRECT ANSWER-----------------dual duct
An air handler unit supplies a constant supply air temperature of 55
degree F to building spaces and includes a coil called _____air handler
unit? ---------CORRECT ANSWER-----------------terminal reheat
An air handler unit that provides heating, cooling, ventilation, and air
conditioning to more than one building or area and has its cooling &
heating Coil in separate side-by side ducts is called a _______air
handling unit? ---------CORRECT ANSWER-----------------multi-zone
In a dual duct air handling system space thermostatic controls building
temperature by? ---------CORRECT ANSWER-----------------Moving the air
from the hot & cold duct in a molding box serving the space.
,A boiler is rated at (86,250 lbs, 88,250 lbs, 96,250 lbs) of steam per
hour. What is the equivalent boiler horsepower? ---------CORRECT
ANSWER-----------------2500 HP = 86,.5 = 2500 lbs
What is the area of a steam engine cylinder reading 10 x 24, when the
piston is only travelling at 2/3 of the way? ---------CORRECT ANSWER-----
------------160. (10 x 24 x 2/3 ) =160
What is the total force acting on a 4 inches diameter safety value disc
with a boiler pressure of 12 psi? ---------CORRECT ANSWER-----------------
150.79 TF= P x A
The expansion tank on a closed loop system should be located? ---------
CORRECT ANSWER-----------------Suction side of the pump
What is the primary purpose of a crank case heater on a reciprocating
chiller? ---------CORRECT ANSWER-----------------To prevent refrigeration
migration
,What is meant by the percent of (skip, step, and slip) in a pump? ---------
CORRECT ANSWER-----------------The difference in theoretical capacity
compared to the actual capacity
Which of the following type of pumps can be started with the discharge
value closed? ---------CORRECT ANSWER-----------------Centrifugal
The vertical distance from the center line of the pump up to the top
level of the supply tank is called? ---------CORRECT ANSWER-----------------
Static suction head
Where in a system is a foot valve value installed and what is its
purpose? ---------CORRECT ANSWER-----------------A type of check value
located below the normal level of the tank attached to the end of the
suction line of the pump, used to keep suction line full to facilitate
starting.
In a multi-zone air handling unit, the zone thermostat controls the zone
temperature by? ---------CORRECT ANSWER-----------------Dampers that
control the air flow from the hot & cold deck
, What is meant by a pump becoming steam bound? ---------CORRECT
ANSWER-----------------When the static pressure at the suction of the
pump falls below the vapor pressure corresponding to its temperature.
Which of the following is a positive displacement pump? ---------
CORRECT ANSWER-----------------reciprocating
What does the whistle on the top of the water column indicating? -------
--CORRECT ANSWER-----------------High and low water condition
The heart of a refrigeration system is the _______? ---------CORRECT
ANSWER-----------------compressor
Refrigerant flow into the evaporator is controlled by ___________? -----
----CORRECT ANSWER-----------------Metering device
A reciprocating compressor operating with refrigerant R-410 head
pressure of 476 psi and a suction pressure of 118 psi. What is the
STATIONARY STEAM ENGINEER LICENSE PREP |
STATIONARY ENGINEER | STATION ENGINEER EXAM |
DC 1ST CLASS BOILER | JUST RELEASED
An air handler unit that has hot & cold air ducts connected to (molding
boxes?) located in each building space is called a __________air
handler unit? ---------CORRECT ANSWER-----------------dual duct
An air handler unit supplies a constant supply air temperature of 55
degree F to building spaces and includes a coil called _____air handler
unit? ---------CORRECT ANSWER-----------------terminal reheat
An air handler unit that provides heating, cooling, ventilation, and air
conditioning to more than one building or area and has its cooling &
heating Coil in separate side-by side ducts is called a _______air
handling unit? ---------CORRECT ANSWER-----------------multi-zone
In a dual duct air handling system space thermostatic controls building
temperature by? ---------CORRECT ANSWER-----------------Moving the air
from the hot & cold duct in a molding box serving the space.
,A boiler is rated at (86,250 lbs, 88,250 lbs, 96,250 lbs) of steam per
hour. What is the equivalent boiler horsepower? ---------CORRECT
ANSWER-----------------2500 HP = 86,.5 = 2500 lbs
What is the area of a steam engine cylinder reading 10 x 24, when the
piston is only travelling at 2/3 of the way? ---------CORRECT ANSWER-----
------------160. (10 x 24 x 2/3 ) =160
What is the total force acting on a 4 inches diameter safety value disc
with a boiler pressure of 12 psi? ---------CORRECT ANSWER-----------------
150.79 TF= P x A
The expansion tank on a closed loop system should be located? ---------
CORRECT ANSWER-----------------Suction side of the pump
What is the primary purpose of a crank case heater on a reciprocating
chiller? ---------CORRECT ANSWER-----------------To prevent refrigeration
migration
,What is meant by the percent of (skip, step, and slip) in a pump? ---------
CORRECT ANSWER-----------------The difference in theoretical capacity
compared to the actual capacity
Which of the following type of pumps can be started with the discharge
value closed? ---------CORRECT ANSWER-----------------Centrifugal
The vertical distance from the center line of the pump up to the top
level of the supply tank is called? ---------CORRECT ANSWER-----------------
Static suction head
Where in a system is a foot valve value installed and what is its
purpose? ---------CORRECT ANSWER-----------------A type of check value
located below the normal level of the tank attached to the end of the
suction line of the pump, used to keep suction line full to facilitate
starting.
In a multi-zone air handling unit, the zone thermostat controls the zone
temperature by? ---------CORRECT ANSWER-----------------Dampers that
control the air flow from the hot & cold deck
, What is meant by a pump becoming steam bound? ---------CORRECT
ANSWER-----------------When the static pressure at the suction of the
pump falls below the vapor pressure corresponding to its temperature.
Which of the following is a positive displacement pump? ---------
CORRECT ANSWER-----------------reciprocating
What does the whistle on the top of the water column indicating? -------
--CORRECT ANSWER-----------------High and low water condition
The heart of a refrigeration system is the _______? ---------CORRECT
ANSWER-----------------compressor
Refrigerant flow into the evaporator is controlled by ___________? -----
----CORRECT ANSWER-----------------Metering device
A reciprocating compressor operating with refrigerant R-410 head
pressure of 476 psi and a suction pressure of 118 psi. What is the
