Requirements for Safe Entry and Cleaning of Petroleum Storage Tanks

API STANDARD 2015 SEVENTH EDITION, MAY 2014

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Contents

Page

1. Scope 1

   1. General 1

   2. Non-applicability and Other Tank Cleaning Applications 1

2. Normative References 1

3. Terms and Definitions 3

4. Administrative Controls and Procedures 14

   1. General Requirements 14

   2. Written Tank Cleaning/Entry Programs 14

   3. Written Tank-specific Cleaning/Entry Plans 14

   4. Regulatory Requirements 15

   5. Tank Cleaning/Entry Overview 16

   6. API Recommended Practice 2016 19

5. Preparing the Tank for Entry and Cleaning 19

   1. Initial Preparation 19

   2. Removal From Service 20

   3. Isolating The Tank 21

   4. Control of Ignition Sources 22

   5. Vapor and Gas Freeing, Degassing, and Ventilating 23

   6. Initial Tank Cleaning 24

6. Testing the Tank Atmosphere 25

   1. Atmospheric Testing Procedures 25

   2. Atmospheric Testing Instruments 25

   3. Atmosphere Testing 25

7. Storage Tank Hazards 27

   1. General 27

   2. Oxygen Deficiency and Enrichment 28

   3. Fire and Explosion Hazards 29

   4. Toxic Substances 29

   5. Physical and Other Hazards 32

   6. Floating Roof Hazards 33

   7. Heat Stress 33

   8. Pyrophoric Iron Sulfide 34

   9. Hazard Assessment 34

8. Personal Protective Equipment 34

   1. Protective Clothing and Equipment 34

   2. Respiratory Protection 35

9. Tank Cleaning/Entry Personnel 38

   1. General 38

   2. Entry Supervisors 39

   3. Entrants 41

   4. Attendants 42

   5. Non-Entry Supervisor Permit Issuers 43

      Contents

      Page

10. Entering and Working Inside the Tank 44

    1. General 44

    2. Entry Permit 44

    3. Floating Roof Stabilization 46

    4. Heat Stress 47

    5. Continuous Forced Air Ventilation 47

    6. Tank Safe (Cold) Work, Maintenance, and Repairs 47

    7. Undesirable Product, Sludge, and Residue Disposal 48

11. Hot Work and Tank Repairs 48

    1. General 48

    2. Hot Work Permits 49

    3. Hot Work Hazards 50

    4. Hot Work In Leaded Service Tanks 51

    5. Fire Prevention 51

12. Emergency Planning 51

    1. Emergency Response Plan 51

    2. Outside Rescue Services 52

    3. Employer Rescuers 53

    4. Rescue Equipment 53

    5. Other Emergencies 54

    6. Medical Emergencies 54

13. Return To Service 55

    1. General 55

    2. Preparation 55

    3. Refilling Tanks 56

    4. Sampling and Gauging Tanks 56

    5. Control of Ignition Sources 57

14. Training 57

    1. General 57

    2. Training Requirements 57

    3. Training Verification 58

    4. Qualification 58

Bibliography 59

Requirements for Safe Entry and Cleaning of Petroleum Storage Tanks

1. Scope

   1. General

      
      

      This standard is applicable to stationary atmospheric and low-pressure (up to and including 15 psig) aboveground petroleum storage tanks used in all sectors of the petroleum and petrochemical industry, including:

      
      

      • crude oil and gas production,

        
        

      • refining,

        
        

      • petrochemicals,

        
        

      • pipelines and terminals,

        
        

      • bulk storage,

        
        

      • ethanol facilities.

        
        

        This standard provides requirements for safely planning, coordinating, and conducting tank entry and cleaning operations, from removal from service through return to service.

        
        

        This standard does not and cannot cover every possible unique hazard or situation that may arise during tank cleaning operations. Site, product, and tank-specific hazards and situations must be addressed by employers using the appropriate principles and considerations provided for by this standard.

        
        

   2. Non-applicability and Other Tank Cleaning Applications

      
      

      This standard does not apply to the following types of tanks or vessels:

      
      

      • pressure vessels and pressurized tanks exceeding 15 psig,

        
        

      • cryogenic or refrigerated vessels or pressure tanks,

        
        

      • vessels and tanks maintained under a vacuum,

        
        

      • process vessels,

        
        

      • underground storage tanks.

      
      

      Although API Standard 2015 is not intended to cover these types of tanks and vessels, many of the safe tank cleaning and entry principles and requirements in this standard apply and should be considered.

      
      

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

API Bulletin E2, Bulletin on Management of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas Production

1