1. What is the minimum slope required for a 4-inch horizontal drainage pipe in
the Philadelphia Plumbing Code?
A) 1/4 inch per foot
B) 1/8 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
✅ Answer: A) 1/4 inch per foot
. Explanation: The IPC and Philadelphia Plumbing Code require 1/4 inch per
foot slope for ≤4-inch pipes to maintain proper flow and avoid blockages.
2. A plumbing permit in Philadelphia is required for which of the following?
A) Replacing a faucet washer
B) Installing a new water heater
C) Clearing a clogged drain with a snake
D) Replacing a showerhead
✅ Answer: B) Installing a new water heater
. Explanation: Permits are required for new fixture installations, water
heaters, piping systems, etc., but minor maintenance like washers or
showerheads do not need permits.
3. Which type of valve is required on the supply line to a water heater?
A) Check valve
B) Ball valve or gate valve
C) Pressure reducing valve
D) Globe valve
,✅ Answer: B) Ball valve or gate valve
. Explanation: Codes require a full-open shutoff valve (ball or gate) on the cold
water supply to water heaters.
4. A trap seal must be at least:
A) 1/2 inch
B) 2 inches
C) 3 inches
D) 4 inches
✅ Answer: B) 2 inches
. Explanation: The trap seal must be at least 2 inches and not more than 4
inches to prevent sewer gases from entering.
5. Which material is not approved for potable water distribution in
Philadelphia?
A) Copper
B) PEX
C) CPVC
D) Lead
✅ Answer: D) Lead
. Explanation: Lead piping is prohibited due to health hazards.
6. The minimum size of a water service pipe for a single-family dwelling is:
A) 1/2 inch
B) 3/4 inch
C) 1 inch
D) 1-1/4 inch
✅ Answer: B) 3/4 inch
. Explanation: Most codes, including Philadelphia’s, require 3/4 inch minimum
water service size to ensure adequate flow.
7. A cleanout must be provided at the base of every:
A) Stack
B) Vent
,C) Trap
D) Branch supply line
✅ Answer: A) Stack
. Explanation: A cleanout is required at the base of stacks to allow
rodding/maintenance access.
8. Backflow prevention for a hose bibb must be provided by:
A) Double check valve
B) Vacuum breaker
C) Reduced pressure zone (RPZ)
D) Atmospheric vent
✅ Answer: B) Vacuum breaker
. Explanation: Hose bibbs must have a vacuum breaker to prevent
backsiphonage.
9. Which of the following fixtures requires an air gap?
A) Clothes washer
B) Dishwasher
C) Lavatory sink
D) Shower
✅ Answer: B) Dishwasher
. Explanation: Dishwashers require an air gap or high loop to protect potable
water supply.
10. In Philadelphia, who is permitted to pull a plumbing permit?
A) Any licensed contractor
B) Property owner without restriction
C) Licensed Master Plumber only
D) Journeyman plumber with experience
✅ Answer: C) Licensed Master Plumber only
. Explanation: Only a licensed Master Plumber (License Type 249) can pull
plumbing permits in Philadelphia.
11. The minimum vertical distance required between a water supply outlet and
the flood rim of a fixture (air gap) is:
, A) Twice the diameter of the outlet
B) 1 inch minimum
C) 2 inches minimum
D) Depends on pipe size
✅ Answer: A) Twice the diameter of the outlet (but not less than 1 inch)
. Explanation: The plumbing code requires an air gap of at least 2x the outlet
diameter, never less than 1 inch.
12. A vent must connect to the trap arm before the trap arm exceeds:
A) 2 feet
B) 4 feet
C) One pipe diameter
D) The developed length allowed by code
✅ Answer: D) The developed length allowed by code
. Explanation: Trap arm length before venting is limited by the trap arm size.
For example, a 2-inch trap arm can extend 5 feet before requiring a vent.
13. The minimum size for a building drain serving one water closet is:
A) 2 inches
B) 3 inches
C) 4 inches
D) 5 inches
✅ Answer: B) 3 inches
. Explanation: Building drains must be minimum 3 inches when serving a
single water closet.
14. Which pipe material may NOT be used for underground drainage piping?
A) Cast iron
B) Schedule 40 PVC
C) ABS (not permitted in Philadelphia)
D) Ductile iron
✅ Answer: C) ABS
. Explanation: Philadelphia code does not permit ABS for underground
drainage piping; cast iron, PVC, and ductile iron are accepted.
the Philadelphia Plumbing Code?
A) 1/4 inch per foot
B) 1/8 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
✅ Answer: A) 1/4 inch per foot
. Explanation: The IPC and Philadelphia Plumbing Code require 1/4 inch per
foot slope for ≤4-inch pipes to maintain proper flow and avoid blockages.
2. A plumbing permit in Philadelphia is required for which of the following?
A) Replacing a faucet washer
B) Installing a new water heater
C) Clearing a clogged drain with a snake
D) Replacing a showerhead
✅ Answer: B) Installing a new water heater
. Explanation: Permits are required for new fixture installations, water
heaters, piping systems, etc., but minor maintenance like washers or
showerheads do not need permits.
3. Which type of valve is required on the supply line to a water heater?
A) Check valve
B) Ball valve or gate valve
C) Pressure reducing valve
D) Globe valve
,✅ Answer: B) Ball valve or gate valve
. Explanation: Codes require a full-open shutoff valve (ball or gate) on the cold
water supply to water heaters.
4. A trap seal must be at least:
A) 1/2 inch
B) 2 inches
C) 3 inches
D) 4 inches
✅ Answer: B) 2 inches
. Explanation: The trap seal must be at least 2 inches and not more than 4
inches to prevent sewer gases from entering.
5. Which material is not approved for potable water distribution in
Philadelphia?
A) Copper
B) PEX
C) CPVC
D) Lead
✅ Answer: D) Lead
. Explanation: Lead piping is prohibited due to health hazards.
6. The minimum size of a water service pipe for a single-family dwelling is:
A) 1/2 inch
B) 3/4 inch
C) 1 inch
D) 1-1/4 inch
✅ Answer: B) 3/4 inch
. Explanation: Most codes, including Philadelphia’s, require 3/4 inch minimum
water service size to ensure adequate flow.
7. A cleanout must be provided at the base of every:
A) Stack
B) Vent
,C) Trap
D) Branch supply line
✅ Answer: A) Stack
. Explanation: A cleanout is required at the base of stacks to allow
rodding/maintenance access.
8. Backflow prevention for a hose bibb must be provided by:
A) Double check valve
B) Vacuum breaker
C) Reduced pressure zone (RPZ)
D) Atmospheric vent
✅ Answer: B) Vacuum breaker
. Explanation: Hose bibbs must have a vacuum breaker to prevent
backsiphonage.
9. Which of the following fixtures requires an air gap?
A) Clothes washer
B) Dishwasher
C) Lavatory sink
D) Shower
✅ Answer: B) Dishwasher
. Explanation: Dishwashers require an air gap or high loop to protect potable
water supply.
10. In Philadelphia, who is permitted to pull a plumbing permit?
A) Any licensed contractor
B) Property owner without restriction
C) Licensed Master Plumber only
D) Journeyman plumber with experience
✅ Answer: C) Licensed Master Plumber only
. Explanation: Only a licensed Master Plumber (License Type 249) can pull
plumbing permits in Philadelphia.
11. The minimum vertical distance required between a water supply outlet and
the flood rim of a fixture (air gap) is:
, A) Twice the diameter of the outlet
B) 1 inch minimum
C) 2 inches minimum
D) Depends on pipe size
✅ Answer: A) Twice the diameter of the outlet (but not less than 1 inch)
. Explanation: The plumbing code requires an air gap of at least 2x the outlet
diameter, never less than 1 inch.
12. A vent must connect to the trap arm before the trap arm exceeds:
A) 2 feet
B) 4 feet
C) One pipe diameter
D) The developed length allowed by code
✅ Answer: D) The developed length allowed by code
. Explanation: Trap arm length before venting is limited by the trap arm size.
For example, a 2-inch trap arm can extend 5 feet before requiring a vent.
13. The minimum size for a building drain serving one water closet is:
A) 2 inches
B) 3 inches
C) 4 inches
D) 5 inches
✅ Answer: B) 3 inches
. Explanation: Building drains must be minimum 3 inches when serving a
single water closet.
14. Which pipe material may NOT be used for underground drainage piping?
A) Cast iron
B) Schedule 40 PVC
C) ABS (not permitted in Philadelphia)
D) Ductile iron
✅ Answer: C) ABS
. Explanation: Philadelphia code does not permit ABS for underground
drainage piping; cast iron, PVC, and ductile iron are accepted.
