1.
What is the minimum inside diameter of a building drain for a one-family
dwelling under the Philadelphia Plumbing Code?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Answer: C. 4 inches
Explanation: The Philadelphia Plumbing Code (adapted from IPC) requires a
minimum 4-inch building drain for any dwelling to ensure proper flow and
prevent clogging.
2.
The minimum slope for a 3-inch horizontal drainage pipe is:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. No slope required
Answer: B. 1/4 inch per foot
Explanation: For pipe sizes 2 1/2 inches or smaller, the required slope is 1/4
in./ft. For larger sizes, 1/8 in./ft. is allowed.
3.
Which material is prohibited for potable water distribution in Philadelphia?
A. Copper (Type L)
B. CPVC
C. Galvanized steel
D. PEX
,Answer: C. Galvanized steel
Explanation: Galvanized steel corrodes and scales over time, contaminating
water and reducing flow, so it is prohibited in new installations.
4.
The minimum cover depth for underground water service pipe is:
A. 6 inches
B. 12 inches
C. 18 inches
D. Below frost line (30 inches minimum in Philadelphia)
Answer: D. Below frost line (30 inches minimum in Philadelphia)
Explanation: Water service piping must be installed below the frost line to
prevent freezing. In Philadelphia, the frost depth is about 30 inches.
5.
What is the maximum trap arm length for a 2-inch trap to vent connection (1/4
in./ft. slope)?
A. 2 feet
B. 4 feet
C. 5 feet
D. 8 feet
Answer: C. 5 feet
Explanation: Under IPC/Philadelphia Code, a 2-inch trap arm may extend up
to 5 feet before venting.
6.
A 4-inch soil stack serving more than 10 water closets must have a minimum
vent size of:
A. 1 1/2 inches
B. 2 inches
C. 3 inches
D. 4 inches
,Answer: D. 4 inches
Explanation: The vent for stacks carrying significant load must equal the stack
size to prevent trap siphonage.
7.
What is the required air gap for a direct-connected dishwasher drain to a food
waste disposer?
A. None required
B. 1 inch minimum
C. 2 inches minimum
D. Twice the pipe diameter
Answer: B. 1 inch minimum
Explanation: Philadelphia follows IPC which requires at least a 1-inch air gap
above the flood rim level.
8.
When testing a drainage system with a water test, the system must be filled with
water to:
A. At least 5 feet head pressure
B. At least 10 feet head pressure
C. Roof overflow level
D. First floor ceiling level
Answer: B. At least 10 feet head pressure
Explanation: Water test requires 10 feet of head for at least 15 minutes with no
leaks.
9.
What type of joint is prohibited in concealed locations?
A. Solvent-welded PVC
B. Mechanical compression fitting
C. Shielded hubless coupling
D. Threaded brass union
, Answer: B. Mechanical compression fitting
Explanation: Compression fittings are not permitted in concealed locations
since they may loosen and leak.
10.
The minimum size of a vent for a single water closet is:
A. 1 1/4 inches
B. 1 1/2 inches
C. 2 inches
D. 3 inches
Answer: C. 2 inches
Explanation: The code requires at least a 2-inch vent for a water closet.
11.
How often must a cleanout be installed in a horizontal drainage line?
A. Every 50 feet
B. Every 75 feet
C. Every 100 feet
D. Only at changes of direction
Answer: C. Every 100 feet
Explanation: Horizontal drain lines require cleanouts at intervals not exceeding
100 feet.
12.
Which of the following requires a grease interceptor under Philadelphia Code?
A. Hospital kitchen
B. Residential sink
C. Mop sink in office
D. Dishwasher in a single-family home
Answer: A. Hospital kitchen
Explanation: Commercial kitchens producing grease-laden waste must install
grease interceptors.
What is the minimum inside diameter of a building drain for a one-family
dwelling under the Philadelphia Plumbing Code?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Answer: C. 4 inches
Explanation: The Philadelphia Plumbing Code (adapted from IPC) requires a
minimum 4-inch building drain for any dwelling to ensure proper flow and
prevent clogging.
2.
The minimum slope for a 3-inch horizontal drainage pipe is:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. No slope required
Answer: B. 1/4 inch per foot
Explanation: For pipe sizes 2 1/2 inches or smaller, the required slope is 1/4
in./ft. For larger sizes, 1/8 in./ft. is allowed.
3.
Which material is prohibited for potable water distribution in Philadelphia?
A. Copper (Type L)
B. CPVC
C. Galvanized steel
D. PEX
,Answer: C. Galvanized steel
Explanation: Galvanized steel corrodes and scales over time, contaminating
water and reducing flow, so it is prohibited in new installations.
4.
The minimum cover depth for underground water service pipe is:
A. 6 inches
B. 12 inches
C. 18 inches
D. Below frost line (30 inches minimum in Philadelphia)
Answer: D. Below frost line (30 inches minimum in Philadelphia)
Explanation: Water service piping must be installed below the frost line to
prevent freezing. In Philadelphia, the frost depth is about 30 inches.
5.
What is the maximum trap arm length for a 2-inch trap to vent connection (1/4
in./ft. slope)?
A. 2 feet
B. 4 feet
C. 5 feet
D. 8 feet
Answer: C. 5 feet
Explanation: Under IPC/Philadelphia Code, a 2-inch trap arm may extend up
to 5 feet before venting.
6.
A 4-inch soil stack serving more than 10 water closets must have a minimum
vent size of:
A. 1 1/2 inches
B. 2 inches
C. 3 inches
D. 4 inches
,Answer: D. 4 inches
Explanation: The vent for stacks carrying significant load must equal the stack
size to prevent trap siphonage.
7.
What is the required air gap for a direct-connected dishwasher drain to a food
waste disposer?
A. None required
B. 1 inch minimum
C. 2 inches minimum
D. Twice the pipe diameter
Answer: B. 1 inch minimum
Explanation: Philadelphia follows IPC which requires at least a 1-inch air gap
above the flood rim level.
8.
When testing a drainage system with a water test, the system must be filled with
water to:
A. At least 5 feet head pressure
B. At least 10 feet head pressure
C. Roof overflow level
D. First floor ceiling level
Answer: B. At least 10 feet head pressure
Explanation: Water test requires 10 feet of head for at least 15 minutes with no
leaks.
9.
What type of joint is prohibited in concealed locations?
A. Solvent-welded PVC
B. Mechanical compression fitting
C. Shielded hubless coupling
D. Threaded brass union
, Answer: B. Mechanical compression fitting
Explanation: Compression fittings are not permitted in concealed locations
since they may loosen and leak.
10.
The minimum size of a vent for a single water closet is:
A. 1 1/4 inches
B. 1 1/2 inches
C. 2 inches
D. 3 inches
Answer: C. 2 inches
Explanation: The code requires at least a 2-inch vent for a water closet.
11.
How often must a cleanout be installed in a horizontal drainage line?
A. Every 50 feet
B. Every 75 feet
C. Every 100 feet
D. Only at changes of direction
Answer: C. Every 100 feet
Explanation: Horizontal drain lines require cleanouts at intervals not exceeding
100 feet.
12.
Which of the following requires a grease interceptor under Philadelphia Code?
A. Hospital kitchen
B. Residential sink
C. Mop sink in office
D. Dishwasher in a single-family home
Answer: A. Hospital kitchen
Explanation: Commercial kitchens producing grease-laden waste must install
grease interceptors.
