PLUMBER’S EXAM | INTERIOR DESIGN PROFESSIONAL EXAM
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
Which of the following traps are permitted by special permission?
A. bell
B. S
C. drum
D. crown vented trap -
CORRECT|ANSWER
C
A roof mounted ari conditioner unit is condensing at the rate of 5 GPM. How much DFU?
A. 4
B. 5
C. 10
D. 12 -
CORRECT|ANSWER
B
According to the International Plumbing Code, when plastic piping is installed in a concealed location
and passing through a stud joist or rafter, the piping may not pass any closer than ___ inches from
the edge of the wood member.
A. 3/4
B. 1
C. 1 1/4
D. 1 1/2 -
CORRECT|ANSWER
D
The measured length along the centerline of the pip and its fittings is?
A. true length
,B. measured length
C. developed length
D. actual length -
CORRECT|ANSWER
C
What is the approximated number of threads for a 2 1/2" schedule 40 pipe which will be used in a
fuel gas piping system?
A. 9
B. 10
C. 11
D. 12 -
CORRECT|ANSWER
D
.43 PSI = How many Feet of Head?
A. 1
B. 2.31
C. 4.4
D. 43 -
CORRECT|ANSWER
A
What is the PSI at the bottom of the drainage pipe if the test for a 4" drainage system is 30' of head?
A. 15 psi
B. 14 psi
C. 13 psi
D. 12 psi -
CORRECT|ANSWER
D
PSI = feet of head x .433
, 30 (feet of head) x .433 = 12.99
When gas piping is installed through wood studs and is less than 1 1/4" from the nearest end of the
stud, the point of passage shall be protected with a face plate not less than ___.
A. 1/32
B. 1/16
C. 3/32
D. 1/8 -
CORRECT|ANSWER
B
What is the corresponding feet of head in a sprinkler system whose pressure is 40 PSI?
A. 93
B. 112
C. 117
D. 116 -
CORRECT|ANSWER
A
Feet of head is 2.31 x PSI
40 x 2.325= 93
A multimeter would test for which of the following?
A. current
B. CFM
C. CFH
D. gallons per hour -
CORRECT|ANSWER
A
How is the vent from an indirect waste pipe run to the outside?
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
Which of the following traps are permitted by special permission?
A. bell
B. S
C. drum
D. crown vented trap -
CORRECT|ANSWER
C
A roof mounted ari conditioner unit is condensing at the rate of 5 GPM. How much DFU?
A. 4
B. 5
C. 10
D. 12 -
CORRECT|ANSWER
B
According to the International Plumbing Code, when plastic piping is installed in a concealed location
and passing through a stud joist or rafter, the piping may not pass any closer than ___ inches from
the edge of the wood member.
A. 3/4
B. 1
C. 1 1/4
D. 1 1/2 -
CORRECT|ANSWER
D
The measured length along the centerline of the pip and its fittings is?
A. true length
,B. measured length
C. developed length
D. actual length -
CORRECT|ANSWER
C
What is the approximated number of threads for a 2 1/2" schedule 40 pipe which will be used in a
fuel gas piping system?
A. 9
B. 10
C. 11
D. 12 -
CORRECT|ANSWER
D
.43 PSI = How many Feet of Head?
A. 1
B. 2.31
C. 4.4
D. 43 -
CORRECT|ANSWER
A
What is the PSI at the bottom of the drainage pipe if the test for a 4" drainage system is 30' of head?
A. 15 psi
B. 14 psi
C. 13 psi
D. 12 psi -
CORRECT|ANSWER
D
PSI = feet of head x .433
, 30 (feet of head) x .433 = 12.99
When gas piping is installed through wood studs and is less than 1 1/4" from the nearest end of the
stud, the point of passage shall be protected with a face plate not less than ___.
A. 1/32
B. 1/16
C. 3/32
D. 1/8 -
CORRECT|ANSWER
B
What is the corresponding feet of head in a sprinkler system whose pressure is 40 PSI?
A. 93
B. 112
C. 117
D. 116 -
CORRECT|ANSWER
A
Feet of head is 2.31 x PSI
40 x 2.325= 93
A multimeter would test for which of the following?
A. current
B. CFM
C. CFH
D. gallons per hour -
CORRECT|ANSWER
A
How is the vent from an indirect waste pipe run to the outside?
