api 571 section_5 refining industry damage mechanisms_pfds_final

September 2010 API Recommended Practice 57 5-89 _______________________________________________________________________________________________

5.2 Process Unit PFDs Simplified process flow diagrams for several process units commonly found in many refineries are shown in this section. The PFDs are highlighted to show some of the areas within the unit where many of the primary damage mechanisms can be found. The reader should be advised that this is not intended to be an all inclusive list of the damage mechanisms but should serve as a starting point for some of the major considerations. The process flow diagrams included in this section are listed below. A key to the Damage Mechanisms The numbering system for damage mechanisms used on the PFDs is shown in Table 5-4.

5.2.1 Crude Unit / Vacuum: See Figure 5-65.

5.2.2 Delayed Coker: See Figure 5-66.

5.2.3 Fluid Catalytic Cracking: See Figure 5-67.

5.2.4 FCC Light Ends Recovery: See Figure 5-68.

5.2.5 Catalytic Reforming CCR: See Figure 5-69.

5.2.6 Catalytic Reforming Fixed Bed: See Figure 5-70.

5.2.7 Hydroprocessing Units Hydrotreating, Hydrocracking: See Figure 5-71.

5.2.8 Sulfuric Acid Alkylation: See Figure 5-72.

5.2.9 HF Alkylation: See Figure 5-73.

5.2.10 Amine Treating: See Figure 5-74.

5.2.11 Sulfur Recovery: See Figure 5-75.

5.2.12 Sour Water Stripper: See Figure 5-76.

5.2.13 Isomerization: See Figure 5-77.

5.2.14 Hydrogen Reforming: See Figure 5-78

5.2.15 Visbreaker: See Figure 5-79.

5.2.16 Caustic Treating: See Figure 5-80.

5-90 API Recommended Practice 571 - Ballot November 2009 ________________________________________________________________________________________________

Table 5-4 Key to Damage Mechanisms

DM# Damage Mechanism DM# Damage Mechanism 1 Sulfidation 34 Softening (Spheroidization) 2 Wet H2S Damage (Blistering/HIC/SOHIC/SSC) 35 Reheat Cracking 3 Creep / Stress Rupture 36 Sulfuric Acid Corrosion 4 High temp H2/H2S Corrosion 37 Hydrofluoric Acid Corrosion 5 Polythionic Acid Cracking 38 Flue Gas Dew Point Corrosion 6 Naphthenic Acid Corrosion 39 Dissimilar Metal Weld (DMW) Cracking 7 Ammonium Bisulfide Corrosion 40 Hydrogen Stress Cracking in HF 8 Ammonium Chloride Corrosion 41 Dealloying (Dezincification/ Denickelification) 9 HCl Corrosion 42 CO2 Corrosion

10 High Temperature Hydrogen Attack 43 Corrosion Fatigue 11 Oxidation 44 Fuel Ash Corrosion 12 Thermal Fatigue 45 Amine Corrosion 13 Sour Water Corrosion (acidic) 46 Corrosion Under Insulation (CUI) 14 Refractory Degradation 47 Atmospheric Corrosion 15 Graphitization 48 Ammonia Stress Corrosion Cracking 16 Temper Embrittlement 49 Cooling Water Corrosion 17 Decarburization 50 Boiler Water / Condensate Corrosion 18 Caustic Cracking 51 Microbiologically Induced Corrosion (MIC) 19 Caustic Corrosion 52 Liquid Metal Embrittlement 20 Erosion / Erosion-Corrosion 53 Galvanic Corrosion 21 Carbonate SCC 54 Mechanical Fatigue 22 Amine Cracking 55 Nitriding 23 Chloride Stress Corrosion Cracking 56 Vibration-Induced Fatigue 24 Carburization 57 Titanium Hydriding 25 Hydrogen Embrittlement 58 Soil Corrosion 26 Steam Blanketing 59 Metal Dusting 27 Thermal Shock 60 Strain Aging 28 Cavitation 61 Sulfate Stress Corrosion Cracking 29 Graphitic Corrosion (see Dealloying) 62 Phosphoric Acid Corrosion 30 Short term Overheating Stress Rupture 63 Phenol (carbolic acid) Corrosion 31 Brittle Fracture 64 Ethanol Stress Corrosion Cracking 32 Sigma Phase/ Chi Embrittlement 65 Oxygen-enhanced Ignition and Combustion

33 885oF (475oC) Embrittlement 66 Organic Acid Corrosion Of Distillation Tower Overhead Systems


Figure 5-65 Crude Unit / Vacuum


Figure 5-66 Delayed Coker


Figure 5-67 Fluid Catalytic Cracking


Figure 5-68 FCC Light Ends Recovery


Figure 5-69 Catalytic Reforming CCR


Figure 5-70 Catalytic Reforming Fixed Bed


Figure 5-71 Hydroprocessing - Hydrotreating, Hydrocracking


Figure 5-72 - Sulfuric Acid Alkylation


Figure 5-73 HF Alkylation


Figure 5-74 Amine Treating


Figure 5-75 Sulfur Recovery


Figure 5-76 Sour Water Stripper


Figure 5-77 Isomerization


Figure 5-78 Hydrogen Reforming


Figure 5-79 Visbreaker


Figure 5-80 Caustic Treating

5.2 Process Unit PFDs5.2.1 Crude Unit / Vacuum: See Figure 5-65.5.2.2 Delayed Coker: See Figure 5-66.5.2.3 Fluid Catalytic Cracking: See Figure 5-67.5.2.4 FCC Light Ends Recovery: See Figure 5-68.5.2.5 Catalytic Reforming CCR: See Figure 5-69.5.2.6 Catalytic Reforming Fixed Bed: See Figure 5-70.5.2.7 Hydroprocessing Units Hydrotreating, Hydrocracking: See Figure 5-71.5.2.8 Sulfuric Acid Alkylation: See Figure 5-72.5.2.9 HF Alkylation: See Figure 5-73.5.2.10 Amine Treating: See Figure 5-74.5.2.11 Sulfur Recovery: See Figure 5-75.5.2.12 Sour Water Stripper: See Figure 5-76.5.2.13 Isomerization: See Figure 5-77.5.2.14 Hydrogen Reforming: See Figure 5-785.2.15 Visbreaker: See Figure 5-79.5.2.16 Caustic Treating: See Figure 5-80.

api 571 section_5 refining industry damage mechanisms_pfds_final

Documents