ASME B31.3 FINAL PAPER 2026 QUESTIONS
WITH ANSWERS GRADED A+
◉ When is leak test performed. Answer: prior to initial operation
after completion of applicable examinations in 341
required
after heat treatment
leave all joints exposed (no insulation)
may be primed and painted Except sensitive leak test
cat D fluid may be insulated at owners option
◉ straight pipe under internal pressure t formula. Answer:
t=P*D/2*(S*E*W+PY)
P=Gage pressure
D=Outer diameter, actual
S=Stress value. Table A-1
E=Quality factor Table A-1A 1.0 for most sml pipe
W=Weld joint reduction factor W. table 302.5. Kicks in at 850F
Y=coefficent Table 304.1.1 0.4 typical
, ◉ t sub m. Answer: tm=t + c
tm= minimum required thickness including mechanical, corrosion, and
erosion allowances
t=pressure design thickness per 304.1.2
c= sum of mechanical allowances.
thread depth+corrosion allowance + erosion allowance
◉ blanks equation location. Answer: 304.5.3
tm=dg*(3P/16SEW)^0.5 + c
dg= ID of gasket for raised or flat face flanges
or to CL for ring joint or other
◉ preliminary pneumatic test. Answer: optional. air at 25 PSIG to locate
major leaks
◉ rules for initial service leak test. Answer: Category D fluid
test fluid is service fluid
gradually increase pressure until lesser of 1/2 test pressure or 25 psi.
preliminary checks for leaks and joints
◉ test fluid for hydro test. Answer: water UNLESS:
WITH ANSWERS GRADED A+
◉ When is leak test performed. Answer: prior to initial operation
after completion of applicable examinations in 341
required
after heat treatment
leave all joints exposed (no insulation)
may be primed and painted Except sensitive leak test
cat D fluid may be insulated at owners option
◉ straight pipe under internal pressure t formula. Answer:
t=P*D/2*(S*E*W+PY)
P=Gage pressure
D=Outer diameter, actual
S=Stress value. Table A-1
E=Quality factor Table A-1A 1.0 for most sml pipe
W=Weld joint reduction factor W. table 302.5. Kicks in at 850F
Y=coefficent Table 304.1.1 0.4 typical
, ◉ t sub m. Answer: tm=t + c
tm= minimum required thickness including mechanical, corrosion, and
erosion allowances
t=pressure design thickness per 304.1.2
c= sum of mechanical allowances.
thread depth+corrosion allowance + erosion allowance
◉ blanks equation location. Answer: 304.5.3
tm=dg*(3P/16SEW)^0.5 + c
dg= ID of gasket for raised or flat face flanges
or to CL for ring joint or other
◉ preliminary pneumatic test. Answer: optional. air at 25 PSIG to locate
major leaks
◉ rules for initial service leak test. Answer: Category D fluid
test fluid is service fluid
gradually increase pressure until lesser of 1/2 test pressure or 25 psi.
preliminary checks for leaks and joints
◉ test fluid for hydro test. Answer: water UNLESS:
