NJ Black Seal Low Pressure Exam | All Questions
and Correct Answers | Graded A+ | Verified
Answers | Just Released | 2026 Version
What is the most readily discernible indication of firing with insufficient secondary
air? ---------CORRECT ANSWER-----------------black smoke coming from the stack
In a two-pipe direct return hot water heating system, the supply and return flow
in the same direction. ---------CORRECT ANSWER-----------------false
What is the maximum size of the bottom blowdown line? ---------CORRECT
ANSWER-----------------2.5"
To avoid the danger of a furnace explosion during start-up, the firing sequence
allows for: ---------CORRECT ANSWER-----------------a pre-purge period
Which of the following would cause scale in a boiler? ---------CORRECT ANSWER----
-------------calcium and magnesium
What is the pressure called in an idle boiler? ---------CORRECT ANSWER---------------
--static pressure
,What is the main purpose of an automatic FW (feedwater) regulator? ---------
CORRECT ANSWER-----------------maintain boiler water level
What happens if a steam trap blows through? ---------CORRECT ANSWER-------------
----steam vents from condensate tank
A log book is needed in all plants that have over how much horsepower? ---------
CORRECT ANSWER-----------------100 horsepower
In a plant that has only 100 horsepower, a licensed operator is required. ---------
CORRECT ANSWER-----------------False
What is the heat content of one therm of natural gas? ---------CORRECT ANSWER--
---------------100,000 Btu's
Carryover can lead to: ---------CORRECT ANSWER-----------------water hammer
, What is the most common cause of problems in a hydronic system? ---------
CORRECT ANSWER-----------------air
The metering combustion control system is sensitive to changes in: ---------
CORRECT ANSWER-----------------steam flow and pressure
If a boiler has been dry fired, what device did not work properly? ---------CORRECT
ANSWER-----------------low water cut-off
What is the line voltage being used in the ignition system on a burner? ---------
CORRECT ANSWER-----------------typically 120 VAC
What is the difference between a safety relief and a safety valve? ---------CORRECT
ANSWER-----------------relief valves open gradually and safety valves open fully at
setpoint pressure
What valve acts similar to a check valve in a hot water system? ---------CORRECT
ANSWER-----------------flow control
Boiler water having a high alkalinity could develop: ---------CORRECT ANSWER-------
----------caustic embrittlement
and Correct Answers | Graded A+ | Verified
Answers | Just Released | 2026 Version
What is the most readily discernible indication of firing with insufficient secondary
air? ---------CORRECT ANSWER-----------------black smoke coming from the stack
In a two-pipe direct return hot water heating system, the supply and return flow
in the same direction. ---------CORRECT ANSWER-----------------false
What is the maximum size of the bottom blowdown line? ---------CORRECT
ANSWER-----------------2.5"
To avoid the danger of a furnace explosion during start-up, the firing sequence
allows for: ---------CORRECT ANSWER-----------------a pre-purge period
Which of the following would cause scale in a boiler? ---------CORRECT ANSWER----
-------------calcium and magnesium
What is the pressure called in an idle boiler? ---------CORRECT ANSWER---------------
--static pressure
,What is the main purpose of an automatic FW (feedwater) regulator? ---------
CORRECT ANSWER-----------------maintain boiler water level
What happens if a steam trap blows through? ---------CORRECT ANSWER-------------
----steam vents from condensate tank
A log book is needed in all plants that have over how much horsepower? ---------
CORRECT ANSWER-----------------100 horsepower
In a plant that has only 100 horsepower, a licensed operator is required. ---------
CORRECT ANSWER-----------------False
What is the heat content of one therm of natural gas? ---------CORRECT ANSWER--
---------------100,000 Btu's
Carryover can lead to: ---------CORRECT ANSWER-----------------water hammer
, What is the most common cause of problems in a hydronic system? ---------
CORRECT ANSWER-----------------air
The metering combustion control system is sensitive to changes in: ---------
CORRECT ANSWER-----------------steam flow and pressure
If a boiler has been dry fired, what device did not work properly? ---------CORRECT
ANSWER-----------------low water cut-off
What is the line voltage being used in the ignition system on a burner? ---------
CORRECT ANSWER-----------------typically 120 VAC
What is the difference between a safety relief and a safety valve? ---------CORRECT
ANSWER-----------------relief valves open gradually and safety valves open fully at
setpoint pressure
What valve acts similar to a check valve in a hot water system? ---------CORRECT
ANSWER-----------------flow control
Boiler water having a high alkalinity could develop: ---------CORRECT ANSWER-------
----------caustic embrittlement
