Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries

API RECOMMENDED PRACTICE 2009 SEVENTH EDITION, FEBRUARY 2002

REAFFIRMED, MARCH 2020

Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries

Safety & Fire Protection

API RECOMMENDED PRACTICE SEVENTH EDITION, FEBRUARY 2002

REAFFIRMED, MARCH 2020

SPECIAL NOTES

API 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 suppliers to warn and properly train and equip their employees, and others exposed, concerning health and 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 materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet.

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?ve years. Sometimes a one-time extension of up to two years will be added to this review cycle. This publication will no longer be in effect ?ve years after its publication date as an operative API standard or, where an extension has been granted, upon republication. Status of the publication can be ascertained from the API Standards Department, [telephone (202) 682-8000]. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.

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API standards are published to facilitate the broad availability of proven, sound 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 be utilized. The formulation and publication of API standards is not intended in any way to inhibit anyone from using any other practices.

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Copyright ? 2002 American Petroleum Institute

FOREWORD

This publication provides guidelines for the protection of personnel and property when performing welding, cutting or other hot work in the petroleum and petrochemical indus- tries. This recommended practice distinguishes between normal hot work activities and those which involve hot work on equipment in service. It provides guidance for certain of these special ?in-service? activities.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may con?ict.

Suggested revisions are invited and should be submitted to the general manager of the API Standards Department, American Petroleum Institute, 1220 L Street, N.W., Washington,

D.C. 20005.

INFORMATION CONCERNING SAFETY AND HEALTH HAZARDS AND PROPER PRECAUTIONS WITH RESPECT TO PARTICULAR MATERIALS AND CONDITIONS SHOULD BE OBTAINED FROM THE EMPLOYER, THE MANU- FACTURER OR SUPPLIER OF THAT MATERIAL, OR THE MATERIAL SAFETY DATA SHEET.

iii

1. General 5

2. Physical Hazards 6

3. Potential Acute Health Hazards and Risk Reduction. 6

4. Potential Chronic Health Hazards and Risk Reduction 6

5. Flammable Liquids, Vapors, Solids, or Dusts 7

6. Combustible Materials 7

7. Ignition Sources 7

8. Water 8

9. Wind 8

10. Equipment with Liners, Blisters, or Patch Plates 8

11. Electrical Hazards to Personnel 8

12. Noise 8

1. IMPLEMENTATION OF SAFEGUARDS 9

   1. General Concepts of Safeguards and Risk Reduction 9

   2. Equipment Purging and Ventilation 9

   3. Protection of Personnel 10

   4. Safeguards Against Ignition Hazards 11

   5. Fire Watch Personnel 11

2. TESTING FOR HAZARDS 12

   1. Flammability Testing 12

   2. Oxygen Testing 12

   3. Monitoring for Toxic Substances 12

   4. Frequency of Monitoring the Atmosphere 12

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Page

1. HOT WORK IN CONFINED SPACES 14

   1. Con?ned Space Entry 14

   2. Oxygen Content in Con?ned Spaces 14

   3. Flammable Vapor Concentration 14

   4. Con?ned Space Ventilation 14

   5. Frequency of Monitoring in Con?ned Spaces 15

   6. Pyrophoric Iron Precautions 15

2. WORK INSIDE VESSELS, EXCHANGERS, AND TANKS 15

   1. Preparations 15

   2. Maintaining a Safe Work Environment 16

   3. Inspection of Internals 16

3. WORK ON THE EXTERIOR OF VESSELS, EXCHANGERS,

   AND TANKS NOT IN SERVICE 16

4. WORK ON EQUIPMENT IN SERVICE 16

   1. Decision Process for Work on Equipment in Service 16

   2. Hot Work With Hydrocarbons Present 16

   3. Work on the Exterior of Atmospheric Pressure In-service Vessels 18

   4. Hot Work on Equipment under Vacuum 18

   5. Leak Repair 18

5. WORK IN BUILDINGS AND PITS 19

6. WORK ON PIPING 19

   1. General Considerations for Work on Piping 19

   2. Piping Isolation 19

   3. Venting of Piping 20

   4. Piping Contamination and Coating 20

   5. Hot Tapping 20

APPENDIX A BIBLIOGRAPHY 21

APPENDIX B INERTING VESSELS 23

Figures

1. Typical Hot Work Activity Flow for Equipment Not in Service 2

2. Example Decision Process for Authorization of Work on

Equipment in Service 17

Tables

1 Welding Hazards and Possible Protection 10

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Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries

SECTION 1—INTRODUCTION

1. PURPOSE

   Gas and electric welding and cutting operations are impor- tant activities to support petroleum and petrochemical opera- tions. Personnel engaged in these operations should have a thorough understanding of the duties they are to perform and the potential hazards associated with the activity and materials involved. This recommended practice provides information to assist welding, cutting and other hot work activities to be done safely in petroleum and petrochemical operations. The under- standing of potential hazards, and application of this knowl- edge, can help reduce the probability and severity of incidents.

   
   

2. SCOPE

   This recommended practice provides guidelines for safely conducting welding, cutting or other hot work activities in re?neries, gas plants, petrochemical plants and other facilities in the petroleum and petrochemical industries. It includes speci?c guidance to evaluate procedures for certain types of work on equipment in service.

   Not included in the scope are:

   1. Guidance for compliance with regulations or codes.

   2. Hot tapping (it is the subject of API Recommended Prac- tice 2201 Procedures for Hot Tapping on Equipment in Service).

   3. Welding techniques, craft skills or quali?cation of welders.

   4. Normal ?safe work? practices such as fall protection, PPE, slip/trip/fall, etc.

   5. Entry or work in inert environments (see API 2217A).

   The principles and resources provided in this document are widely applicable. Some activities (such as oil drilling or off- shore operations) may be subject to speci?c regulations or unique work requirements which should be considered when developing welding and hot work programs.

   While personnel doing welding and other hot work require a high degree of skill and shall be quali?ed for the work they are doing, the quali?cation of personnel falls outside the scope of this document.

   API 2009 intends to maintain consistency and compatibil- ity with ANSI/AWS Z49.1 which provides much more detail on welding equipment, PPE and certain procedures and NFPA 51B that focuses on ?res and explosions with guidance

   covering a broad spectrum of applications including struc- tures. Additional guidance relating to welding equipment, techniques, processes and testing used in the chemical, oil, gas and pipeline industries is provided by API RP 582, API Std 1104 and API RP 1107.

   
   

3. RETROACTIVITY

   Any provisions in this publication related to procedures or design are intended for new project reference such as revising procedures or designing new facilities, or when considering major revisions or expansions. It is not intended that any rec- ommendations in this publication be applied retroactively to existing facilities or evaluation of prior practice. This recom- mended practice should provide useful guidance when there is a desire or need to review programs or facilities.

   
   

4. CONCEPT OF HAZARD VS RISK

   Hazards are properties of materials with the inherent abil- ity to cause harm. Flammability, toxicity, corrosivity, and stored chemical or mechanical energy all are hazards associ- ated with various industrial materials. Risk requires exposure. A hot surface or material can cause thermal skin burns or a corrosive acid can cause chemical skin burns, but these can occur only if there is contact exposure to skin. There is no risk when there is no potential for exposure.

   Determining the level of risk involves understanding haz- ards and estimating the probability and severity of exposure that could lead to harm. While the preceding examples relate hazards to the risk to people, the same principles are valid for evaluating property risk. For instance, hydrocarbon vapors in a ?ammable mixture with air can ignite if exposed to a source of ignition resulting in a ?re that could damage property.

   
   

5. GENERAL HOT WORK PROCESS

The discussion of safe ?hot work? in this publication fol- lows the process ?ow chart shown in Figure 1. This chart shows a typical ?ow sequence for welding activities in the petroleum and petrochemical industries. Sections of this doc- ument that discuss those steps are indicated. Other facilities may have alternative work ?ow processes, or may combine some steps.

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