P99 LOW PRESSURE BOILER
LICENSE EXAM QUESTIONS AND
THEIR 100% CORRECT ANSWERS
Name the most frequent cause for failure on cast iron
boilers?
cracking due to overheating (low water) or thermal shock
What is the maximum size of safety valve permitted on
a heating boiler?
4 1/2 inches
What is the function of a boiler vent?
It is used to vent air from the boiler when filling with water
or warming the boiler, and to prevent vacuum from forming
when taking the boiler offline.
What is the function of low water fuel cut-off?
It shuts off the boiler burner in the event of a low water
What is the function of the operating pressure
control?
An automatic device that controls the starting and stopping
of the burner on steam pressure demand.
Explain the term "water hammer".
Banging cause by steam and water mixing in a steam line.
What is the first thing a boiler operator must do when
taking over a shift ?
Check the water level on all boilers that are online/working
Name two pressure controls required on a steam
heating boiler.
, Modulating pressure control, pressure control or ON/OFF
conbustion control
What determines the frequency of boiler blowdown?
Feed water annalist
What is an induced draft fan?
Mechanical draft produced by a power driven fan located
between the boiler and the chimney
Steam boilers are required to have a steam gauge,
what are hot water boilers required to have?
Temperature Pressure Gauge
What is a compound gauge?
It indicates pressure on one side and vacuum on the other
Why are cross tees provided on water column piping?
For inspection of steam and water lines for scale build-up
What is the maximum pressure allowed on a cast iron
sectional boiler?
15psi
What is meant by purging the furnace?
To remove explosive combustibles from the furnace that
could lead to a furnace explosion.
The steam boiler component used to lower the
concentration of dissolved impurities in the boiler
water is the:
Blow-off connection.
To reduce corrosion in large hydronic heating
systems, a gas cushion is recommended in the
expansion tank consisting of.
Nitrogen
What is the maximum allowable working pressure of a
boiler during hydrostatic testing?
150%
LICENSE EXAM QUESTIONS AND
THEIR 100% CORRECT ANSWERS
Name the most frequent cause for failure on cast iron
boilers?
cracking due to overheating (low water) or thermal shock
What is the maximum size of safety valve permitted on
a heating boiler?
4 1/2 inches
What is the function of a boiler vent?
It is used to vent air from the boiler when filling with water
or warming the boiler, and to prevent vacuum from forming
when taking the boiler offline.
What is the function of low water fuel cut-off?
It shuts off the boiler burner in the event of a low water
What is the function of the operating pressure
control?
An automatic device that controls the starting and stopping
of the burner on steam pressure demand.
Explain the term "water hammer".
Banging cause by steam and water mixing in a steam line.
What is the first thing a boiler operator must do when
taking over a shift ?
Check the water level on all boilers that are online/working
Name two pressure controls required on a steam
heating boiler.
, Modulating pressure control, pressure control or ON/OFF
conbustion control
What determines the frequency of boiler blowdown?
Feed water annalist
What is an induced draft fan?
Mechanical draft produced by a power driven fan located
between the boiler and the chimney
Steam boilers are required to have a steam gauge,
what are hot water boilers required to have?
Temperature Pressure Gauge
What is a compound gauge?
It indicates pressure on one side and vacuum on the other
Why are cross tees provided on water column piping?
For inspection of steam and water lines for scale build-up
What is the maximum pressure allowed on a cast iron
sectional boiler?
15psi
What is meant by purging the furnace?
To remove explosive combustibles from the furnace that
could lead to a furnace explosion.
The steam boiler component used to lower the
concentration of dissolved impurities in the boiler
water is the:
Blow-off connection.
To reduce corrosion in large hydronic heating
systems, a gas cushion is recommended in the
expansion tank consisting of.
Nitrogen
What is the maximum allowable working pressure of a
boiler during hydrostatic testing?
150%
