What is boiler accumulation pressure test?

flowchart TD
    A[Start full firing] --> B[Shut off feed water]
    B --> C[Close all stop valves]
    C --> D[Isolate from other boilers]
    D --> E[Run test: ≤15 min shell / ≤7 min water-tube]
    E --> F{Accumulation ≤10% working pressure?}
    F -->|Yes| G[Test passed]
    F -->|No| H[Test failed]

• Definition: test that checks how fast pressure rises in a boiler when steam generation continues with feed water shut off
• Purpose: verify safety valves can relieve steam fast enough to prevent overpressure
• Conditions: full firing, feed water shut off, all stop valves closed, no communication between boilers
• Duration: ≤15 min for shell boilers, ≤7 min for water-tube boilers
• Acceptance: pressure accumulation must not exceed 10% of the working pressure
• Special cases: waste-heat boilers tested at max engine load; composite boilers under full firing
• IMO basis: SOLAS 74/88 Regulation II-1/26 requires pressure tests for boilers and systems under internal pressure