MASTER MECHANICAL LICENSE EXAM
QUESTIONS AND ANSWERS
What is the min. clearance required between a manhole cover installed at the top of a
boiler & the ceiling directly above? - Answer-3'
All the following of boilers require valves in their supply & return lines EXCEPT -
Answer-Low pressure (15psi) steam boilers
What type of valve may be placed between the boiler safety valve & the atmosphere on
the discharge pipe from the valve? - Answer-No valve can be located there
When an isolation transfer is provided, what safety devices prevent a boiler from
operating once the underground side becomes interrupted? - Answer-Control & limit
devices
A limit control for a group A boiler shall be wired so that when the contacts open the
circuit shall be interrupted on the... - Answer-underground side
What is the purpose of a Low Water Cut Out on a low pressure boiler? - Answer-to cut
off fuel supply
A high probability system is located in a residential occupied space with an occupied
volume of 12,000 cubic feet. What is the max amount of R-22 allowed? - Answer-66lbs
A 400,000BTU gas furnace is located in a confined space and all the air is drawn in
from inside the building. What is the min. allowable free area of each permanent
opening that ventilates the room? - Answer-400sq in
What is the min. Pitch of a condensate drain connected to a compensating furnace? -
Answer-1/8"
How is the input rating of an appliance converted into cubic foot of gas? - Answer-Divide
BTU input by the heat valve of the gas
A pre-fabricated double wall vertical vent from a gas furnace is called... - Answer-Type
B
Combustion air from an appliance will come from a room that has 8' ceiling, that is
12'X16', with a 12"X16" combustion air duct. What is the max BTU input? - Answer-
30720
Combustion air vent opening that terminates on the outside of a building shale be
covered with a carrion-resistan screen that has a min wire mesh size of ... - Answer-1/4"
, Gas piping may run through? - Answer-Kitchen cabinets
A gas line is being leak tested. The testing gas shall be... - Answer-Air, Carbon Dioxide,
Nitrogen
What is the min. test pressure for a fuel gas system designed to operate at 2psi? -
Answer-3psi
A fuel gas regulator installed next to an appliance & required a vent. Where shall the
vent be piped to? - Answer-To the outside of the building
What max length is permitted for metal flex line to a residents furnace? - Answer-3'
What min. pitch per foot is required for a horizontal run of a vent pipe? - Answer-1/4"
Mechanical joints are to be used to connect steel pipe in a fuel-oil supply system. The
joints shall be made with an approved... - Answer-pipe dope compound
All the following can be used for LP gas line EXCEPT - Answer-cast iron
What shall be installed to prevent excessive pressure build up in sections of LP gas
pipe that can be isolated from the remainder of the systems? - Answer-Hydrostatic relief
valves
What working pressure is required for steel fittings in an LP gas system that will have 30
psi? - Answer-128psi
The outside bottom of a horizontal ASME LP gas container shall be mounted a max of
what height above ground? - Answer-12"
Underground gas pipe shall be buried not less than what depth in the surface of the
ground? - Answer-12"
Who is responsible for providing hard hats on a jobsite? - Answer-Employer
Employees on a jobsite can safely be exposed to what max peak sound pressure? -
Answer-140 db
All of the following eye protectors are recommended to protect workers exposure to
flying particles from chipping and grinding EXCEPT - Answer-Flexible fitted hooded
ventilated goggles
What shall be the max distance from a hazard to a portable fire extinguisher? - Answer-
100'
QUESTIONS AND ANSWERS
What is the min. clearance required between a manhole cover installed at the top of a
boiler & the ceiling directly above? - Answer-3'
All the following of boilers require valves in their supply & return lines EXCEPT -
Answer-Low pressure (15psi) steam boilers
What type of valve may be placed between the boiler safety valve & the atmosphere on
the discharge pipe from the valve? - Answer-No valve can be located there
When an isolation transfer is provided, what safety devices prevent a boiler from
operating once the underground side becomes interrupted? - Answer-Control & limit
devices
A limit control for a group A boiler shall be wired so that when the contacts open the
circuit shall be interrupted on the... - Answer-underground side
What is the purpose of a Low Water Cut Out on a low pressure boiler? - Answer-to cut
off fuel supply
A high probability system is located in a residential occupied space with an occupied
volume of 12,000 cubic feet. What is the max amount of R-22 allowed? - Answer-66lbs
A 400,000BTU gas furnace is located in a confined space and all the air is drawn in
from inside the building. What is the min. allowable free area of each permanent
opening that ventilates the room? - Answer-400sq in
What is the min. Pitch of a condensate drain connected to a compensating furnace? -
Answer-1/8"
How is the input rating of an appliance converted into cubic foot of gas? - Answer-Divide
BTU input by the heat valve of the gas
A pre-fabricated double wall vertical vent from a gas furnace is called... - Answer-Type
B
Combustion air from an appliance will come from a room that has 8' ceiling, that is
12'X16', with a 12"X16" combustion air duct. What is the max BTU input? - Answer-
30720
Combustion air vent opening that terminates on the outside of a building shale be
covered with a carrion-resistan screen that has a min wire mesh size of ... - Answer-1/4"
, Gas piping may run through? - Answer-Kitchen cabinets
A gas line is being leak tested. The testing gas shall be... - Answer-Air, Carbon Dioxide,
Nitrogen
What is the min. test pressure for a fuel gas system designed to operate at 2psi? -
Answer-3psi
A fuel gas regulator installed next to an appliance & required a vent. Where shall the
vent be piped to? - Answer-To the outside of the building
What max length is permitted for metal flex line to a residents furnace? - Answer-3'
What min. pitch per foot is required for a horizontal run of a vent pipe? - Answer-1/4"
Mechanical joints are to be used to connect steel pipe in a fuel-oil supply system. The
joints shall be made with an approved... - Answer-pipe dope compound
All the following can be used for LP gas line EXCEPT - Answer-cast iron
What shall be installed to prevent excessive pressure build up in sections of LP gas
pipe that can be isolated from the remainder of the systems? - Answer-Hydrostatic relief
valves
What working pressure is required for steel fittings in an LP gas system that will have 30
psi? - Answer-128psi
The outside bottom of a horizontal ASME LP gas container shall be mounted a max of
what height above ground? - Answer-12"
Underground gas pipe shall be buried not less than what depth in the surface of the
ground? - Answer-12"
Who is responsible for providing hard hats on a jobsite? - Answer-Employer
Employees on a jobsite can safely be exposed to what max peak sound pressure? -
Answer-140 db
All of the following eye protectors are recommended to protect workers exposure to
flying particles from chipping and grinding EXCEPT - Answer-Flexible fitted hooded
ventilated goggles
What shall be the max distance from a hazard to a portable fire extinguisher? - Answer-
100'
