ACTUAL QUESTIONS AND CORRECTLY
WELL DEFINED ANSWERS LATEST
ALREADY GRADED A+ 2025 – 2026
What sized corrugated stainless steel tubing should be
installed to get 248000 BTU of undiluted propane to an
appliance 82 feet away with an inlet pressure 11.0 in. w.c.,
pressure drop of 0.5 in. w.c. and a specific gravity of 1.50? -
ANSWERS-Tubing size 37 (EHD)
What test medium should NEVER be used to pressure test
gas piping? - ANSWERS-Oxygen
When using metallic pipe for gas supply, what is the
approximate length of the threaded portion of a 1-1/4"
pipe? - ANSWERS-1"
,What is the MINIMUM amount of time that can be required
to perform a pressure test on a 1,250 foot steel gas line in a
manufacturing plant? - ANSWERS-1.5 hours
What is the MINIMUM required clearance for a vent
connector used on a medium-heat appliance with a single -
wall metal pipe? - ANSWERS-36"
When cutting threads on a 1" steel pipe that is being used
for a gas line, how many threads should be cut for each
joint? - ANSWERS-10
For a material to be considered non-combustible it must
pass the ASTM E 136 test in a vertical tube furnace at what
temperature? - ANSWERS-750 degrees C
What is the minimal burial depth underground for a gas line
installation? - ANSWERS-12"
A service station is being built with one boiler 28 feet away
from the meter that uses natural gas; all other equipment is
electric. What size K or L semi-rigid copper tubing should be
installed to supply 205 cu. ft. of gas per hour with an inlet
, pressure less than 2 psi, pressure drop of 0.3 in. W.C. and a
specific gravity of 0.60? - ANSWERS-1 "
Maximum distance a gas shut-off valve can be installed from
the equipment it serves? - ANSWERS-6 feet
Maximum distance off the ceiling of the room shall an
indoor combustion air opening be installed? - ANSWERS-12"
What is the minimum required clearance for an unlisted
pool heater on all sides and rear? - ANSWERS-12"
Flanges used for gas piping shall have gaskets made of an
approved material designed to withstand temperatures,
pressure and chemical constituents of the gas. Which of the
following gasket materials is not acceptable? - ANSWERS-
Rubber
When corrosive or flammable fumes or gases are present
near appliances, a safe disposal method shall be provided.
All of the following are considered flammable or corrosive
EXCEPT?! - ANSWERS-Anhydrous Citric Acid