FE Other Disciplines Practice Question Solution included after investigation
CASE E-093 Β· FE

The Relief Valve That Saw 480 N, Not 560

The vessel pressure was 700 kPa absolute, but the valve disk also had atmospheric pressure acting on the opposite side. Net pressure force depended on the 600 kPa differential.

β–Ά INTERACTIVE CASE FILE β€’ 5–10 MIN β€’ CLICK TO INVESTIGATE

Inspect, commit, prove, fix, and sign off.

Case E-093 engineering failure visual
HOW THIS WORKS

Think like
a real engineer.

Follow the investigation process used in the field β€” in five guided steps.

1

Inspect

Review the problem, diagram, and evidence.

2

Commit

Choose your hypothesis.

3

Prove

Run calculations and test your idea.

4

Fix

Select and validate a safe correction.

5

Sign Off

See the full debrief and key takeaways.

Case Brief

SAME PRINCIPLES. HIGHER STANDARDS.
PROBLEM STATEMENT

A pressure-relief valve disk has an effective area of 8.0 cmΒ². The vessel side is at 700 kPa absolute and the discharge side is at 100 kPa absolute. A note calculates 700 kPaΓ—8.0 cmΒ² and reports 560 N as the net opening pressure force. Determine the correct net force due to pressure difference.

Safety Health Environment Other Disciplines Design Verification Root Cause Analysis Safe Correction
E-093
INVESTIGATION WORKSPACE WORK THROUGH THE CASE β€” YOUR CHOICES MATTER.
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DEBRIEF (LOCKED)

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to unlock the full debrief.

Find the root cause, confirm the fix, and see how this connects to the exam.

πŸ”’Root causeComplete the case
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πŸ”’Correct fixComplete the case
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πŸ”’Exam takeawayComplete the case
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CASE CLOSED Β· ENGINEERING VERDICT

What actually failed β€” and what should change.

What failed

Internal absolute pressure was treated as the full net pressure difference.

What was missed

Atmospheric pressure acts on the opposite side of the disk.

Corrected model

Use F=(Pin-Pout)A with consistent units.

QUICK ANSWER

Ξ”P=700-100=600 kPa. With A=8 cmΒ²=0.0008 mΒ², F=600000Γ—0.0008=480 N.

ENGINEERING TAKEAWAY

For opposing uniform pressures, net pressure force is F=(Pin-Pout)A using consistent units.

CASE QUESTIONS

Questions this case should settle.

Why subtract the outside pressure?

Because pressure acts on both sides of the disk in opposite directions.

What is the net force for an 800 kPa differential across 5 cmΒ²?

400 N.

NEXT FE PRACTICE QUESTION

The Source That Fell to 30, Not 60

Safety Health Environment Β· 5–10 min

Continue Practice β†’
WHAT YOU’LL LEARN

Real failures. Lasting skills.

Each case is designed to build the judgment, analysis, and confidence you need for engineering exams β€” and beyond.

  • Apply core engineering concepts to real-world problems
  • Practice structured troubleshooting and analysis
  • Strengthen exam-ready thinking through realistic scenarios
COMMON QUESTIONS
Do I need prior knowledge to use these cases?

Basic subject familiarity helps, but every case is designed to teach through the investigation itself.

How long does a case take?

Most cases are designed for a focused 5–10 minute investigation.

Are the cases aligned with engineering exams?

Each case is mapped to a verified exam, subject, topic, and misconception before publication.

What happens after I complete a case?

The sealed debrief unlocks with the root cause, corrected reasoning, fix, and takeaway.