Refining and Petrochemical Company HAZOP Minute Sheet

Project: Crude Distillation Unit

Node: 2

Draw No:1

Node Description: Desalter and Associated Pipe Work

Guide Word

Cause

Consequence

Safeguards

Recommendation

1. High Pressure

1. Automatic pressure controllers 10-PRC-1 failed

2. Discharge line L1 partially blocked causing low discharge rate

3. Low discharge rate of pump 10-P-25AB

1. Poor salt dissolution from the crude

2. Formation of more stable oil-water emulsion difficult to separate

1. Pressure safety valve will pop open and transformer will trip

1. Frequently check and maintain pressure controller

2. Install low pressure alarm

3. Frequently check and maintain flow lines and pumps

2. Low Pressure

1. Automatic pressure controller 10-PRC-1 failed

1. Vapourisation of light ends from desalter

2. Transformer trips off

1. Frequently check and maintain pressure controller

3. High Temperature

1. High crude residence time in heat exchangers

1. Loss of light ends from crude

1. Install temperature regulator

2. Install High temperature alarm

4. Low Temperature

1. Fouling of heat exchangers

2. Preheat train network failed

1. Poor settling and oil loss in the effluent water

1. Install temperature regulator

2. Install Low temperature alarm

5. High Level

1. Level controller 10-dLRC-3 faulty

2. Discharge pump 10-P-25AB failed

3. Waste water valve V5 blocked

1. Carryover of interface with oil into tower causing fouling and corrosion of downstream equipment

2. Level rises to electrode causing current flow and transformer trips

1. Install high level alarm

2. Frequently check and maintain pumps and valves

6. Low Level

1. Level controller 10-DLRC-3 faulty

2. Mixer valve V4 partly blocked

1. Carryover of crude with effluent water

1. Install low level alarm

2. Check mixer valve