Mlng Scw Cmp
CORROSION MONITORING & MITIGATION PLAN FOR 4CG-5235
07 JULY 2012
A. CORROSION GROUP DATA Corrosion Group ID Corrosion Group Name Process Service Material of Construction Corrosion Group Description 4CG-5235 Sea Cooling Water Sea Cooling Water Piping(CS,cement,U.G/A.G);Tube(Al Br),Channel(Cu) The group consist of sea cooling water supplied to all sea cooling water exchanger in Module 4. Unit 5200: Sea cooling water to various heat exchangers with temperature range between 30 to 50 degC and pressure 3barg Sea Cooling Water (SCW) exchangers provide cooling medium for process and utilities units. The source of SCW is located at Terminal SCW intake system. This SCW is pumped to the modules via four SCW pumps. Mechanical and chemical treatment of the seawater is required because of debris and marine life presence. The intake station contains a series of screening facilities (bucket sieve screens and rotating drum screens to remove floating solids from the seawater. Sodium hypochlorite is also added to the seawater to prevent multiplication of marine organisms in the system. Sodium hypochlorite is produced electrolytically from seawater by the electrochlorinaton units. The free residual chlorine (FRC) is maintained between 0.5-0.7 ppm at the SCW pumps discharge header and between 0.2-0.5 ppm at the SCW outfall channel. The purpose of having excess FRC is to ensure enough chlorine is dosed to prevent the marine growth. SCW enters the module at ambient temperature while the exit temperature is controlled not to exceed DOE requirement of 40°C.
Process Description
PRIVATE & CONFIDENTIAL
Damage Mechanism Summary
Tube (Al-Br) and Channel (Cu) Internal Corrosion: 1. Erosion-Corr: At tube ends; due to high velocity. Erosion corrosion can occur in flowing liquid-solid streams or in gas-solid streams. Erosional velocity limits are as follows: a) Al-Br: 2.4 m/s b) 90-10 Cu-Ni: 3.0 m/s c) 70-30 Cu-Ni: 3.7 m/s 2. P-Erosion: Carry-over of sand, silt, debris in
07 JULY 2012
A. CORROSION GROUP DATA Corrosion Group ID Corrosion Group Name Process Service Material of Construction Corrosion Group Description 4CG-5235 Sea Cooling Water Sea Cooling Water Piping(CS,cement,U.G/A.G);Tube(Al Br),Channel(Cu) The group consist of sea cooling water supplied to all sea cooling water exchanger in Module 4. Unit 5200: Sea cooling water to various heat exchangers with temperature range between 30 to 50 degC and pressure 3barg Sea Cooling Water (SCW) exchangers provide cooling medium for process and utilities units. The source of SCW is located at Terminal SCW intake system. This SCW is pumped to the modules via four SCW pumps. Mechanical and chemical treatment of the seawater is required because of debris and marine life presence. The intake station contains a series of screening facilities (bucket sieve screens and rotating drum screens to remove floating solids from the seawater. Sodium hypochlorite is also added to the seawater to prevent multiplication of marine organisms in the system. Sodium hypochlorite is produced electrolytically from seawater by the electrochlorinaton units. The free residual chlorine (FRC) is maintained between 0.5-0.7 ppm at the SCW pumps discharge header and between 0.2-0.5 ppm at the SCW outfall channel. The purpose of having excess FRC is to ensure enough chlorine is dosed to prevent the marine growth. SCW enters the module at ambient temperature while the exit temperature is controlled not to exceed DOE requirement of 40°C.
Process Description
PRIVATE & CONFIDENTIAL
Damage Mechanism Summary
Tube (Al-Br) and Channel (Cu) Internal Corrosion: 1. Erosion-Corr: At tube ends; due to high velocity. Erosion corrosion can occur in flowing liquid-solid streams or in gas-solid streams. Erosional velocity limits are as follows: a) Al-Br: 2.4 m/s b) 90-10 Cu-Ni: 3.0 m/s c) 70-30 Cu-Ni: 3.7 m/s 2. P-Erosion: Carry-over of sand, silt, debris in