PHA

Module from the Process Safety Management Curriculum curriculum.

Module 2 - Process Hazard Analysis · Learning Objectives · 1. Select PHA method: HAZOP (best for existing), What-If (brownfield), FMEA (equipment) · 2. Divide unit into nodes (typical 20-50 per unit) · 3. Apply HAZOP guide words (No, More, Less, Reverse, As Well As, Part Of, Other Than) · 4. Assess consequence and likelihood using risk matrix · 5. Document recommendations and track to closure · HAZOP Guide Word Template

Parameter	Guide Word	Typical Deviation	Causes	Consequence	Safeguards
Flow	No	No flow	Pump off, line blocked	Loss of cooling, overheat	Low flow alarm, cross-tie
Flow	More	Higher flow	Control valve open, bypass	Overflow, overload	High flow alarm
Flow	Less	Reduced flow	Partial blockage, pump low	Poor separation	Low flow alarm
Flow	Reverse	Backflow	Pump trip, check valve fail	Contamination	Check valve, NRV
Pressure	More	Over-pressure	Valve closed, fire	Vessel rupture	PSV, SIS
Pressure	Less	Vacuum	Cooling, level too low	Vessel collapse	Vacuum breaker
Temperature	More	High temp	Cooling failure	Runaway	TIC, SIS
Temperature	Less	Low temp	Loss of heat	Freezing, waxing	TIC, heat tracing
Level	More	High level	Inflow, level control fail	Overflow, pump cavitation	LIC, LAH+
Level	Less	Low level	Outflow, level fail	Pump damage	LAL, SIS
Composition	As Well As	Contamination	Cross-contamination	Off-spec	QC sampling
Reaction	Reverse	Runaway polymerization	Catalyst fines, foul	Over-pressure	Emergency quench

Source: Process_Safety_Management_Curriculum_v1.xlsx · Sheet: PHA

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