PLUMBING RED SEAL 100(400) 02 EXAM
QUESTIONS AND ANSWERS 2026
126) A positive displacement pump, a gear pump must be equipped with?
a) pressure relief valve
b) pressure switch
c) pressure reducing valve
d) pressure tank - ANSWERSa) pressure relief valve
Explanation: A positive displacement pump like a gear pump must be equipped
with a pressure relief valve. This is because these pumps can generate high
pressure, and the relief valve prevents excess pressure buildup that could
damage the system.
127) What is the correct process for repairing a damaged CPVC pipe fitting on a
hydronic heating system?
a) Drain, isolate remove joint apply primer solvent weld to new spool and fitting
and install
b) Isolate, drain remove joint solvent weld to new spool and fitting and install
c) Isolate, drain remove joint apply primer to new spool and fitting and install
d) Isolate, drain remove joint apply primer solvent weld to new spool and fitting
and install - ANSWERS127. d) Isolate, drain remove joint apply primer solvent weld to
new spool and
fitting and install
Explanation: The correct process for repairing a damaged CPVC pipe fitting
involves isolating and draining the system, removing the damaged joint,
applying primer, then solvent welding to a new spool and fitting before
installation.
128) This device is used to prevent the entry of gases into a structure.
a) Gasket
b) P trap
c) Ball valve
d) Quick tee adaptor - ANSWERS128. b) P trap
Explanation: A P trap is used to prevent the entry of gases into a structure. It
maintains a water seal that stops sewer gases from coming back up through the
drainage system into the building.
129) How is the flush duration of a conventional diaphragm-style flushometer
valve lengthened?
a) Install a new vacuum breaker.
b) Open the control stop fully.
c) Turn the flushometer bonnet screw counter clockwise.
,d) Turn the bypass screw counter clockwise - ANSWERS129. d) Turn the bypass screw
counter clockwise.
Explanation: To lengthen the flush duration of a conventional diaphragm-style
flushometer valve, the bypass screw should be turned counter clockwise. This
adjustment allows more water to pass through during flushing.
130) Even in the fully open state, all valves experience some degree of frictional
flow loss. Which kind of valve reduces flow the most even while it is open?
a) globe
b) gate
c) plug valve
d) swing check valve - ANSWERS130. a) globe
Explanation: Globe valves, even when fully open, reduce flow the most among
the options given. This is due to their design, which causes a change in the
direction of flow within the valve, creating more frictional flow loss.
131) If 600 feet of pipe weighs 900 pounds, how much would 140 feet of the
same pipe weigh?
a) 210
b) 202
c) 217
d) 190 - ANSWERS131. a) 210
Explanation: The weight of the pipe is proportional to its length. Thus, for 140 feet
of pipe: ( \frac{900 \text{ lbs}}{600 \text{ ft}} = \frac{x \text{ lbs}}{140 \text{ ft}} ).
Solving for x gives 210 lbs.
132) Which of the following voltages provides the most energy efficiency?
a) 240 static voltage.
b) 220 line voltage.
c) 110 line voltage.
d) 120 static voltage. - ANSWERS132. a) 240 static voltage.
Explanation: Generally, higher voltages like 240 static voltage are more energy
efficient, especially for larger or industrial appliances, as they draw less current
for the same power output
133) Maximum number of water closet vents that may be attached to a 1-1/2 in
branch vent.
a) 4
b) 8
c) 3
d) 2 - ANSWERS133. d) 2
Explanation: The maximum number of water closet vents that may be attached
to a 1-1/2 inch branch vent is typically 2. This ensures adequate venting
capacity for the fixtures.
, 134) Empty, a 60 gallon water heater weights 52.5 pounds. How much does it
weigh when it is completely filled?
a) 581
b) 553
c) 564
d) 500 - ANSWERS134. b) 553
Explanation: Water weighs about 8.34 pounds per gallon. So, a 60-gallon water
heater would weigh 52.5 pounds + (60 gallons × 8.34 pounds/gallon) = 52.5 +
500.4 = 552.9 pounds, approximately 553 pounds.
135) Before choosing a hydronic circulator, what must be determined?
a) System resistance and flow rate.
b) System resistance and pipe size.
c) Height of building and flow rate.
d) Height of building and pipe size. - ANSWERS135. a) System resistance and flow
rate.
Explanation: Before choosing a hydronic circulator, it's important to determine
the system resistance and flow rate. These factors ensure that the circulator can
handle the system's hydraulic requirements
136) The coil of a hydronic heating and cooling convector are identical. How
many pipes will enter the convector?
a) Two for heating and one for cooling.
b) One for heating and two for cooling.
c) One for heating and one for cooling.
d) Two for both the heating and cooling. - ANSWERS136. d) Two for both the heating
and cooling.
Explanation: A hydronic heating and cooling convector with identical coils will
have two pipes entering the convector, one for heating and one for cooling.
137) When the water pressure changes, which approach will rectify the
occasional discharge from a reduced pressure principle backflow preventer?
a) Install a swing check valve upstream of the RP.
b) Install a swing check valve downstream of the RP.
c) Put in a stronger check valve spring upstream of the RP.
d) Restrict the water flow to the RP by using a globe valve. - ANSWERS137. c) Put in a
stronger check valve spring upstream of the RP.
Explanation: Installing a stronger check valve spring upstream of a reduced
pressure principle backflow preventer (RP) can help rectify occasional
discharges due to water pressure changes.
138) Which connecting technique is only permitted for underground and outside
water service piping?
a) Soldering the joint.
b) Brazing the joint.
c) Flaring the pipe.
QUESTIONS AND ANSWERS 2026
126) A positive displacement pump, a gear pump must be equipped with?
a) pressure relief valve
b) pressure switch
c) pressure reducing valve
d) pressure tank - ANSWERSa) pressure relief valve
Explanation: A positive displacement pump like a gear pump must be equipped
with a pressure relief valve. This is because these pumps can generate high
pressure, and the relief valve prevents excess pressure buildup that could
damage the system.
127) What is the correct process for repairing a damaged CPVC pipe fitting on a
hydronic heating system?
a) Drain, isolate remove joint apply primer solvent weld to new spool and fitting
and install
b) Isolate, drain remove joint solvent weld to new spool and fitting and install
c) Isolate, drain remove joint apply primer to new spool and fitting and install
d) Isolate, drain remove joint apply primer solvent weld to new spool and fitting
and install - ANSWERS127. d) Isolate, drain remove joint apply primer solvent weld to
new spool and
fitting and install
Explanation: The correct process for repairing a damaged CPVC pipe fitting
involves isolating and draining the system, removing the damaged joint,
applying primer, then solvent welding to a new spool and fitting before
installation.
128) This device is used to prevent the entry of gases into a structure.
a) Gasket
b) P trap
c) Ball valve
d) Quick tee adaptor - ANSWERS128. b) P trap
Explanation: A P trap is used to prevent the entry of gases into a structure. It
maintains a water seal that stops sewer gases from coming back up through the
drainage system into the building.
129) How is the flush duration of a conventional diaphragm-style flushometer
valve lengthened?
a) Install a new vacuum breaker.
b) Open the control stop fully.
c) Turn the flushometer bonnet screw counter clockwise.
,d) Turn the bypass screw counter clockwise - ANSWERS129. d) Turn the bypass screw
counter clockwise.
Explanation: To lengthen the flush duration of a conventional diaphragm-style
flushometer valve, the bypass screw should be turned counter clockwise. This
adjustment allows more water to pass through during flushing.
130) Even in the fully open state, all valves experience some degree of frictional
flow loss. Which kind of valve reduces flow the most even while it is open?
a) globe
b) gate
c) plug valve
d) swing check valve - ANSWERS130. a) globe
Explanation: Globe valves, even when fully open, reduce flow the most among
the options given. This is due to their design, which causes a change in the
direction of flow within the valve, creating more frictional flow loss.
131) If 600 feet of pipe weighs 900 pounds, how much would 140 feet of the
same pipe weigh?
a) 210
b) 202
c) 217
d) 190 - ANSWERS131. a) 210
Explanation: The weight of the pipe is proportional to its length. Thus, for 140 feet
of pipe: ( \frac{900 \text{ lbs}}{600 \text{ ft}} = \frac{x \text{ lbs}}{140 \text{ ft}} ).
Solving for x gives 210 lbs.
132) Which of the following voltages provides the most energy efficiency?
a) 240 static voltage.
b) 220 line voltage.
c) 110 line voltage.
d) 120 static voltage. - ANSWERS132. a) 240 static voltage.
Explanation: Generally, higher voltages like 240 static voltage are more energy
efficient, especially for larger or industrial appliances, as they draw less current
for the same power output
133) Maximum number of water closet vents that may be attached to a 1-1/2 in
branch vent.
a) 4
b) 8
c) 3
d) 2 - ANSWERS133. d) 2
Explanation: The maximum number of water closet vents that may be attached
to a 1-1/2 inch branch vent is typically 2. This ensures adequate venting
capacity for the fixtures.
, 134) Empty, a 60 gallon water heater weights 52.5 pounds. How much does it
weigh when it is completely filled?
a) 581
b) 553
c) 564
d) 500 - ANSWERS134. b) 553
Explanation: Water weighs about 8.34 pounds per gallon. So, a 60-gallon water
heater would weigh 52.5 pounds + (60 gallons × 8.34 pounds/gallon) = 52.5 +
500.4 = 552.9 pounds, approximately 553 pounds.
135) Before choosing a hydronic circulator, what must be determined?
a) System resistance and flow rate.
b) System resistance and pipe size.
c) Height of building and flow rate.
d) Height of building and pipe size. - ANSWERS135. a) System resistance and flow
rate.
Explanation: Before choosing a hydronic circulator, it's important to determine
the system resistance and flow rate. These factors ensure that the circulator can
handle the system's hydraulic requirements
136) The coil of a hydronic heating and cooling convector are identical. How
many pipes will enter the convector?
a) Two for heating and one for cooling.
b) One for heating and two for cooling.
c) One for heating and one for cooling.
d) Two for both the heating and cooling. - ANSWERS136. d) Two for both the heating
and cooling.
Explanation: A hydronic heating and cooling convector with identical coils will
have two pipes entering the convector, one for heating and one for cooling.
137) When the water pressure changes, which approach will rectify the
occasional discharge from a reduced pressure principle backflow preventer?
a) Install a swing check valve upstream of the RP.
b) Install a swing check valve downstream of the RP.
c) Put in a stronger check valve spring upstream of the RP.
d) Restrict the water flow to the RP by using a globe valve. - ANSWERS137. c) Put in a
stronger check valve spring upstream of the RP.
Explanation: Installing a stronger check valve spring upstream of a reduced
pressure principle backflow preventer (RP) can help rectify occasional
discharges due to water pressure changes.
138) Which connecting technique is only permitted for underground and outside
water service piping?
a) Soldering the joint.
b) Brazing the joint.
c) Flaring the pipe.
