1、Guidelines and Procedures forEntering and Cleaning PetroleumStorage TanksANSI/API RECOMMENDED PRACTICE 2016FIRST EDITION, AUGUST 2001REAFFIRMED, MAY 1, 2006Guidelines and Procedures forEntering and Cleaning PetroleumStorage TanksDownstream SegmentANSI/API RECOMMENDED PRACTICE 2016FIRST EDITION, AUGU
2、ST 2001REAFFIRMED, MAY 1, 2006SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to partic-ular circumstances, local, state, and federal laws and regulations should be reviewed.API is not undertaking to meet the duties of employers, manufacturers, or supplie
3、rs towarn and properly train and equip their employees, and others exposed, concerning healthand safety risks and precautions, nor undertaking their obligations under local, state, or fed-eral laws.Information concerning safety and health risks and proper precautions with respect to par-ticular mate
4、rials and conditions should be obtained from the employer, the manufacturer orsupplier of that material, or the material safety data sheet.Nothing contained in any API publication is to be construed as granting any right, byimplication or otherwise, for the manufacture, sale, or use of any method, a
5、pparatus, or prod-uct covered by letters patent. Neither should anything contained in the publication be con-strued as insuring anyone against liability for infringement of letters patent.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least everyfive years. Sometimes
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10、und engineer-ing and operating practices. These standards are not intended to obviate the need for apply-ing sound engineering judgment regarding when and where these standards should beutilized. The formulation and publication of API standards is not intended in any way toinhibit anyone from using
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13、Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 2001 American Petroleum InstituteFOREWORDThis recommended practice was prepared under the auspices of the API Safety and FireProtection Subcommittee. It is provided for the use of API member companies and others inthe develop
14、ment and implementation of company and facility specific safe practices forplanning, managing, and conducting tank cleaning operations in petroleum storage tanks.API publications may be used by anyone desiring to do so. Every effort has been made bythe Institute to assure the accuracy and reliabilit
15、y of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or municipal r
16、egulation with which thispublication may conflict.Suggested revisions are invited and should be submitted to the standardization manager,American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.iiiCONTENTSPage1 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . 11.3 Regulatory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Administrative Controls and Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、 . . . . . . . . . . . . . . . . . . . . . . . . 22.1 Codes, Standards, and Related Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 United States Government Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 Other Publications and References . .
20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . 33.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 PETROLEUM STORAGE TANK HAZARDS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.1 Hazards. . . . . . . . . . . . . . . . . . . . . . . .
22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.2 Oxygen Deficiency and Enrichment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.3 Fires and Explosions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.4 Toxi
23、c Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.5 Stress Exposures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.6 Physical and Other Hazards. . . . . . . . . . . . . . . . . . . .
24、. . . . . . . . . . . . . . . . . . . . 175 VAPOR AND GAS FREEING, DEGASSING, AND VENTILATING TANKS. . . . 185.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.2 Vapor and Gas Freeing (and Degassing) Hazards. . . . . . . .
25、. . . . . . . . . . . . . . . 195.3 Mechanical Vapor and Gas Freeing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205.4 Steam Vapor Freeing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315.5 Natural Ventilation . . . . . . . . . . .
26、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315.6 Inert Gas Purging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325.7 Displacement of Vapors Using Water (Fuel Oil). . . . . . . . . . . . . . . . . . . . . . . . 335.8 Deg
27、assing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 REMOVING SLUDGE AND RESIDUE FROM TANKS . . . . . . . . . . . . . . . . . . . . . 396.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、 . . . . . . . . . . . . 396.2 Pumping and Vacuum Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396.3 Safe Removal Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396.4 Noninvasive Removal . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406.5 Removal from Outside the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406.6 Removal from Inside the Tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436.7 Sludge Disposal . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 UNIQUE TANKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31、. . . . . . . . . . . . . . . . . . . . . . 447.2 Very Large Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.3 Floating Roof Tanks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.4 Double Wall an
32、d Double Bottom Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477.5 Low Pressure Storage Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487.6 Conservation Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33、. . . . . 49vPage8 SPECIFIC HAZARDOUS SUBSTANCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498.2 Tanks with Pyrophoric Iron Sulfide Deposits . . . . .
34、. . . . . . . . . . . . . . . . . . . . . 498.3 Cleaning Tanks With Products That Contain Hydrogen Sulfide (H2S) . . . . . . 508.4 Tanks That Have Been In Leaded Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518.5 Tanks Containing Hazardous Sludge and Residue . . . . . . . . . . .
35、. . . . . . . . . . . 539 CONTROL OF IGNITION SOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549.2 Internal Combustion Engines . . . . . . .
36、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549.3 Electrical Motors and Generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559.4 Artificial Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559.5 Ele
37、ctrical Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559.6 Lightning Storms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559.7 Pyrophoric Iron Sulfide Deposits . . . . . . . . . . . . . . . .
38、. . . . . . . . . . . . . . . . . . . 569.8 Hot Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569.9 Smoking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5610 TANK CLEAN
39、ING CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5610.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5610.2 Preplanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40、. . . . . . . . . . . . . . . . . . . . . . 5610.3 Removing Recoverable Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6110.4 Tank Isolation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6610.5 Vapor-Freeing the
41、Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6710.6 Atmospheric Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6910.7 Cleaning the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42、 . . . . . . . . . . . . . 7110.8 Working Inside and Around the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7810.9 Returning the Tank to Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8010.10 Recommissioning . . . . . . . . . . . . . . .
43、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8110.11 Recommissioning Safety Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8311 OXYGEN, COMBUSTIBLE GAS, AND TOXIC SUBSTANCE INSTRUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44、 . . . . . . . . . . . . . . . . . . . . . 8511.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8511.2 Oxygen Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8511.3 Comb
45、ustible Gas (Flammable Vapor) Indicators . . . . . . . . . . . . . . . . . . . . . . . 8511.4 Toxic Substance Testing Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8712 FLOATING ROOF HAZARDS ASSOCIATED WITH TANK CLEANING. . . . . . 8812.1 General . . . . . . . . . . . .
46、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8812.2 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8812.3 Floating Roof Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47、 . . . . . . . . . . . . . . 8812.4 Floating Roof Legs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8912.5 Roof Failure and Collapse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8912.6 Entry Onto or Below Floating Ro
48、ofs (and Into Pontoons) . . . . . . . . . . . . . . . . 9312.7 Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9312.8 Floating Roof Temporary Support Requirements. . . . . . . . . . . . . . . . . . . . . . . 94Figures4-1 Example o
49、f Ventilation for Welding Fumes During Hot Work . . . . . . . . . . . . . . 155-1 Tank Ventilation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21viPage5-2 Example of Air Mover Located on Shell Manway of Tank. . . . . . . . . . . . . . . . . 225-3 Example of Tank Mechanical Vapor-Freeing Equipment . . . . . . . . . . . . . . . . . . 225-4 Sample Tank Ventilation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245-5 Examples of Typical Ventilation Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . 26
