COSC 325 PLUMBING EXAM
QUESTIONS AND ANSWERS
Different types of valves - Answer-a. Angle - a globe valve in which the inlet and outlet
are at 90 degrees to each other. Commonly used at elbows
b. Ball - a valve in which fluid flow is controlled by a ball that fits tightly against a resilient
seat in the valve body
c. Butterfly - a valve used to control fluid flow. It consists of a rotating disk that seats
against a resilient material within the valve body
d. Check - a valve that allows flow in only one direction
e. Pressure reducing/pressure regulating valve - is an automatic device used to convert
high and/or fluctuating inlet water pressure to a lower or constant outlet pressure
DFU (drainage fixture unit) - Answer-is the measure of probable discharge of
wastewater and waterborne waste into the drainage system formulated in tests
conducted by the international association of plumbing and mechanical officials, which
developed the uniform plumbing code
Grade/Pitch/Slope for drainage pipe - Answer-¼" per foot. Can be less than ¼" though
Cleanouts - Answer-a. Purpose, and where they should be installed - allows access to
the system if stoppage occurs.
- Front main cleanout - at the outside wall of the building at the connection of the
building sewer and building drain
- Stack base clean out - at the base of all vertical soil or waste stacks
- At all 90-degree changes in direction
- At the upper terminal of all horizontal branch drains
- Every 50' on 3" and smaller horizontal drainage pipe; every 100' on 4" and larger
horizontal drainage pipe
b. Accessibility - clean outs must be easily accessible. If cleanouts are in walls or
ceilings access panels are constructed to provide access.
c. Protection during construction - cleanouts for underground applications must be
closely watched when backfilling operations so the cleanouts remain intact and are not
buried or damaged
Fitting - Answer-A device fastened to the end of pipes to make connections between
individual pipes
Valve - Answer-is a fitting used to regulate fluid flow within a system
PVC (Polyvinyl Chloride) - Answer-plastic pipe and fittings used for sanitary drainage
and vent piping, above ground and underground storm water drainage, water mains,
and water service lines
QUESTIONS AND ANSWERS
Different types of valves - Answer-a. Angle - a globe valve in which the inlet and outlet
are at 90 degrees to each other. Commonly used at elbows
b. Ball - a valve in which fluid flow is controlled by a ball that fits tightly against a resilient
seat in the valve body
c. Butterfly - a valve used to control fluid flow. It consists of a rotating disk that seats
against a resilient material within the valve body
d. Check - a valve that allows flow in only one direction
e. Pressure reducing/pressure regulating valve - is an automatic device used to convert
high and/or fluctuating inlet water pressure to a lower or constant outlet pressure
DFU (drainage fixture unit) - Answer-is the measure of probable discharge of
wastewater and waterborne waste into the drainage system formulated in tests
conducted by the international association of plumbing and mechanical officials, which
developed the uniform plumbing code
Grade/Pitch/Slope for drainage pipe - Answer-¼" per foot. Can be less than ¼" though
Cleanouts - Answer-a. Purpose, and where they should be installed - allows access to
the system if stoppage occurs.
- Front main cleanout - at the outside wall of the building at the connection of the
building sewer and building drain
- Stack base clean out - at the base of all vertical soil or waste stacks
- At all 90-degree changes in direction
- At the upper terminal of all horizontal branch drains
- Every 50' on 3" and smaller horizontal drainage pipe; every 100' on 4" and larger
horizontal drainage pipe
b. Accessibility - clean outs must be easily accessible. If cleanouts are in walls or
ceilings access panels are constructed to provide access.
c. Protection during construction - cleanouts for underground applications must be
closely watched when backfilling operations so the cleanouts remain intact and are not
buried or damaged
Fitting - Answer-A device fastened to the end of pipes to make connections between
individual pipes
Valve - Answer-is a fitting used to regulate fluid flow within a system
PVC (Polyvinyl Chloride) - Answer-plastic pipe and fittings used for sanitary drainage
and vent piping, above ground and underground storm water drainage, water mains,
and water service lines
