Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries API RECOMMENDED PRACTICE 2009 SEVENTH EDITION, FEBRUARY 2002 Safe Welding, Cutting, and Hot Work Practices i[.]
Purpose
Gas and electric welding and cutting are crucial for petroleum and petrochemical operations It is essential for personnel involved in these activities to fully understand their responsibilities and the associated hazards This recommended practice offers guidance to ensure that welding, cutting, and other hot work are conducted safely within these industries By recognizing potential hazards and applying this knowledge, the likelihood and severity of incidents can be significantly minimized.
Scope
This guideline outlines safe practices for performing welding, cutting, and other hot work activities in refineries, gas plants, petrochemical facilities, and related industries It offers specific recommendations for assessing procedures related to work on equipment that is currently in service.
The scope does not encompass guidance for regulatory or code compliance, nor does it include hot tapping, which is addressed in API Recommended Practice 2201 regarding procedures for hot tapping on equipment.
Welding techniques and the qualifications of welders are essential for ensuring safety in the workplace Adhering to standard safety practices, including fall protection and the use of personal protective equipment (PPE), is crucial to prevent slip, trip, and fall incidents Additionally, proper procedures must be followed when entering or working in inert environments, as outlined in API 2217A.
This document outlines widely applicable principles and resources, emphasizing the need to consider specific regulations and unique work requirements for certain activities, such as oil drilling and offshore operations, when developing welding and hot work programs.
Welding and hot work require highly skilled personnel who must be qualified for their specific tasks; however, the qualifications of these individuals are not covered in 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 addresses fire and explosion hazards, offering comprehensive guidance applicable to various structures Additionally, API RP 582, API Std 1104, and API RP 1107 provide further insights on welding equipment, techniques, processes, and testing specifically for the chemical, oil, gas, and pipeline industries.
Retroactivity
This publication offers guidance on procedures and design for new projects, including revisions and expansions, but is not meant to be applied retroactively to existing facilities or past practices It serves as a valuable resource for reviewing programs or facilities when necessary.
Concept of Hazard vs Risk
Hazards are characteristics of materials that can lead to harm, including flammability, toxicity, corrosivity, and stored energy Understanding these hazards is crucial in industrial settings, as risk is determined by the level of exposure to these dangerous properties.
Contact with hot surfaces or corrosive acids can lead to thermal or chemical skin burns, respectively However, the risk of such injuries only exists when there is direct exposure to the skin Without potential exposure, there is no associated risk.
Assessing risk requires a thorough understanding of hazards and an estimation of the likelihood and potential impact of exposure that may cause harm This approach not only applies to risks affecting individuals but is also crucial for evaluating property risks For example, hydrocarbon vapors mixed with air can ignite when exposed to an ignition source, leading to a fire that poses a threat to property.
General Hot Work Process
This publication outlines the safe "hot work" procedures, following the workflow chart depicted in Figure 1, which illustrates a standard sequence for welding activities in the petroleum and petrochemical sectors Relevant sections of the document detail these steps, while acknowledging that other facilities may implement different workflows or combine certain steps.
Figure 1—Typical Hot Work Activity Flow for Equipment Not in Service
EVALUATE WORK CONDITIONSEVALUATE WORK CONDITIONS
CARRY OUT CARRY OUT WORK WORK
TYPICAL HOT WORK ACTIVITY FLOW
For Equipment Not in Service
Appropriate Persons Sign Work Permit
S AFE W ELDING , C UTTING , AND H OT W ORK P RACTICES IN THE P ETROLEUM AND P ETROCHEMICAL I NDUSTRIES 3
The publications listed in this section are speciịcally refer- enced in this publication Additional relevant references are listed in the Appendix A Bibliography.
API 510 Pressure Vessel Inspection Code: Mainte- nance Inspection, Rating, Repair and Alteration
API 570 Piping Inspection Code: Inspection,
Repair, Alteration, and Re-Rating of In- Service Piping Systems
RP 582 Welding Guidelines for the Chemical, Oil, and Gas Industries
Std 653 Tank Inspection, Repair, Alteration, and
Std 1104 Welding of Pipelines and Related Facilities
RP 1107 Pipeline Maintenance Welding Practices
RP 2003 Protection Against Ignitions Arising Out
Of Static, Lightning, and Stray Currents
Std 2015 Safe Entry and Cleaning of Petroleum
RP 2016 Recommended Practice for Entering and
Publ 2027 Ignition Hazards Involved in Abrasive
Blasting of Atmospheric Storage Tanks in Hydrocarbon Service
RP 2201 Procedures for Welding or Hot Tapping on
Publ 2207 Preparing Tank Bottoms for Hot Work
Publ 2217A Guidelines for Work in Inert Conịned
Space in the Petroleum Industry
Threshold Limit Values TLVs¨ and Biolog- ical Exposure Indices BEIs¨
Z49 1 Safety in Welding, Cutting and Allied Pro- cesses (ANSI/AWS)
Guidelines for Hot Work in Conịned Spaces; Martin H Finkel, ASSE Press 1999
F 3.1 Guide for Welding Fume Control
National Board 6 ANSI/NB-23 National Board Inspection Code
NFPA 7 51B Standard for Fire Prevention During Weld- ing, Cutting, and Other Hot Work
NIOSH 8 Pub 88-110 Criteria for a Recommended Standard:
Welding, Brazing, and Thermal Cutting
Pub 99-115 Pocket Guide to Chemical Hazards and
OSHA 9 1910.119 Process Safety Management of Highly
1910.147 Control of Hazardous Energy (Lockout/
1910.251-7 Subpart Q Welding, Cutting, and Brazing
1910.1000 (and following) Subpart Z, ÒToxic and
1926.354 Welding, Cutting, and Heating in Way of
2American Conference of Governmental Industrial Hygienists, 6500
Glenway Avenue, Building D-5, Cincinnati, Ohio 45211. www.acgih.org
3American National Standards Institute, 25 West 43rd Street, New
York, New York 10036 www.ansi.org
4American Society of Safety Engineers, 33477 Treasury Center, Chicago, Illinois 60694-3400 www.asse.org
5American Welding Society, 550 N.W LeJeune Road, Miami, Flor- ida 33126 www.aws.org
6National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Avenue, Columbus, Ohio 43229 www.nationalboard.org
7National Fire Protection Association, Batterymarch Park, Quincy, Massachusetts 02269 www.nfpa.org
8National Institute for Occupational Safety and Health (NIOSH) Centers for Disease Control and Prevention (CDC) NIOSH/CDC,
4676 Columbia Parkway, Cincinnati, Ohio 45226 www.cdc.gov/ niosh
9U.S Department of Labor, Occupational Safety and Health Admin- istration, 200 Constitution Avenue, N.W Washington, D.C 20210.www.osha.gov
Terms used in this publication are deịned in this section
Acute hazards are substances that can lead to health effects from short-term exposure, typically within minutes or hours Such exposure may result in both immediate and long-lasting health consequences.
3.2 chronic health hazard: Capable of causing adverse health effects resulting from exposure over a long period of time (often at low-level concentrations).
A competent person, as defined by OSHA 1926.32, is an individual designated by the employer who possesses the ability to recognize both existing and potential hazards in the workplace that may pose risks to personnel This person is authorized to implement immediate corrective actions to mitigate these hazards The definition of a competent person is performance-based and varies according to the specific work context.
A confined space is defined as an enclosure that presents known or potential hazards and has limited access points, typically not occupied by individuals and often poorly ventilated In the petroleum industry, examples of confined spaces include process vessels, vessel tower skirts, flare stacks, boilers, storage tanks, tank cars and trucks, vaults, large-diameter piping, and, under certain conditions, underground areas like pits (OSHA 1910.146).
3.5 exposure limit: For chemical agents, a measure of the maximum airborne concentration limits for toxic sub- stances to which workers may be exposed without protection
(e.g., respirators) Exposure limits are usually expressed in parts per million or milligrams per cubic meter Material
Safety Data Sheets (MSDSs) from the manufacturer or sup- plier of the material should list exposure limits
3.6 fume: Small diameter particulate matter formed when vaporized high molecular weight materials condense from the gaseous state Although solids, fumes are small enough to behave like gases
3.7 hazard: An inherent chemical or physical property with the potential to do harm (òammability, toxicity, corrosiv- ity, stored chemical or mechanical energy)
Hot work refers to operations that generate sufficient heat from flames, sparks, or other ignition sources to ignite flammable vapors, gases, or dust This includes activities such as electric arc and gas welding, chipping, flaming, grinding, gas cutting, abrasive blasting, brazing, and soldering It is essential to follow special procedures and obtain permits when conducting hot work in designated areas.
D of ANSI Z49.1 lists more than 90 welding and allied pro- cesses that would qualify as Òhot work.Ó)
3.9 hydrogen blister: Bulge in steel caused by high- pressure molecular hydrogen trapped at an internal òaw within steel.
Inerting is the process of removing the risk of a flammable atmosphere by introducing an inert gas, such as nitrogen, carbon dioxide, or steam, to displace the oxygen necessary for ignition.
The lower flammable limit (LFL) refers to the minimum concentration of a vapor in air, or another oxidant, that prevents the propagation of flame upon contact with an ignition source This limit is typically expressed as a volume percentage of the vapor in air and is also known as the Lower Explosive Limit (LEL).
3.12 permissible exposure limits (PELs): Federal regulations set by the Occupational Safety and Health Administration, U.S Department of Labor, and found at 29
Code of Federal Regulations 1910.1000 and in the substance- speciịc standards which follow
A 3.13 permit is a formal document that authorizes a specific work activity and outlines the conditions for its execution It is typically signed by both the recipient and an authorized issuing individual, ensuring that the activity is permitted to proceed under defined guidelines.
Personal protective equipment (PPE) includes items like protective clothing, respiratory devices, and shields designed to safeguard individuals' eyes, face, head, and extremities from potential hazards in their environment or during processes that could lead to injury or functional impairment.
3.15 purging: The process of eliminating the potential for a òammable atmosphere by displacing hydrocarbons from a potential hot work area to eliminate the fuel required for ignition
A qualified person is an individual appointed by the employer who possesses a recognized degree, certificate, or professional standing, or has extensive knowledge, training, and experience This person has demonstrated the ability to identify and resolve issues related to the work or project and is properly licensed as required by federal, state, or local laws and regulations.
3.17 risk: The probability of exposure to a hazard which could result in harm to personnel, property, the environment or general public.
3.18 risk assessment: The identiịcation and analysis,either qualitative or quantitative, of the likelihood and out-
S AFE W ELDING , C UTTING , AND H OT W ORK P RACTICES IN THE P ETROLEUM AND P ETROCHEMICAL I NDUSTRIES 5 come of speciịc events or scenarios with judgements of prob- ability and consequences
3.19 risk-based analysis: A review of potential needs based on a risk assessment.
3.20 threshold limit values (TLVs¨): Recommended exposure limits published annually by the American Confer- ence of Governmental Industrial Hygienists in Threshold
Limit Values and Biological Exposure Indices (TLV¨ is a registered trademark of the American Conference of Govern- mental Industrial Hygienists.)
The upper flammable limit (UFL) refers to the highest concentration of vapor in air or another oxidant that prevents flame propagation upon contact with an ignition source Typically expressed as a volume percentage, the UFL is also known as the Upper Explosive Limit (UEL) In simpler terms, a mixture with a flammable vapor percentage exceeding the UFL is considered "too rich" to ignite, while a mixture below the lower flammable limit (LFL) is deemed "too lean" to burn.
3.22 welder: The person operating gas or electric welding equipment; the person physically doing the welding In some publications this person is referred to as a welding operator.
Job Analysis
The initial phase of the work process involves defining the objectives and the methods for achieving them Conducting a work scope analysis is essential to explore potential alternatives to hot work activities, ensuring they fall within feasible engineering and economic limits This stage is also an opportune moment to evaluate alternative procedures, such as cold cutting.
When hot work is necessary, it is essential to follow established priorities for safety and compliance First, the work should be relocated to a designated safe area, such as a maintenance welding shop or a remote fabrication site, whenever feasible If relocation is not possible, an assessment must be made to determine if nearby fire hazards can be moved to a safer location In cases where the hot work object cannot be moved and fire hazards remain, implementing physical barriers is crucial to contain potential ignition sources.
(such as heat, sparks, and slag) and to protect the immovable ịre hazards from ignition
When hot work is unavoidable, it is essential to thoroughly analyze each activity for potential hazards, including those outlined in this publication and the relevant Material Safety Data Sheets (MSDSs) Implementing appropriate safeguards can significantly reduce the risks of personnel exposure and ignition hazards that may result in fire or explosion Additionally, it is crucial to consider the consequences of each identified hazard and any unforeseen conditions that may arise during the hot work process.
Effective contingency plans are essential for safely managing hot work operations, incorporating alternative methods like adjustments in plant operations when needed These plans must address potential incidents, including requirements for fire fighting, personnel evacuation, and community notifications.
Before commencing work on specific equipment, it is essential to obtain review and approval from qualified individuals Tasks such as hot work, welding, or repairs on vessels, exchangers, and tanks necessitate evaluation by experienced engineering personnel, pressure equipment specialists, or licensed inspectors This review process is crucial when technical expertise or adherence to regulatory standards is required.
This review should be conducted as part of the job analysis.
SECTION 5—HAZARD EVALUATION AND RISK REDUCTION
Hazards are inherent characteristics associated with specific materials, activities, or situations that cannot be altered However, by understanding these hazards, it is possible to eliminate hazardous materials, restructure activities, or adopt alternative work methods, thereby reducing or eliminating exposure-dependent risks Conducting a thorough job analysis of potential hazards and operations before commencing work is essential This analysis aids in identifying the necessary safeguards, engineering controls, and personal protective equipment required for safe work execution.
This safety analysis can be part of the normal permit proce- dure The following sections discuss hazards (including
In 2009, the API recommended practices address employee physical safety and health concerns related to welding and hot work activities, including fire safety Section 6 outlines further techniques for risk reduction.
Welding environments share many hazards with typical workplaces, necessitating the use of personal protective equipment (PPE) and precautions against slip, trip, and fall risks When working at heights, it is essential to adhere to the facility's fall protection procedures and utilize appropriate equipment Additionally, arc welding relies on electric power, and tasks performed in confined spaces require adequate lighting It is crucial to follow suitable electrical work practices for all electrical equipment, particularly in wet or moist conditions.
(including perspiration) where there is potential for contact with metal parts which are Òelectrically hotÓ (see 5.11).
In welding environments, particularly in confined spaces, the work area can become cluttered with numerous cables, hoses, and lines Although standard safety procedures should be followed, it is beneficial to reassess the arrangement of equipment to minimize the risk of tripping hazards.
Hot work and welding processes generate significant heat, necessitating the use of suitable protective clothing to prevent thermal burns Injuries can arise from sparks or molten metal entering pockets, rolled-up sleeves, pant cuffs, or work boots Additionally, frayed clothing poses a higher risk of ignition.
Eye and face injuries can result from flying particles, molten metal, liquid chemicals, acids, caustic liquids, or chemical gases and vapors To ensure safety, it is essential to implement work practices that protect individuals from falling sparks, chips, and slag, especially when working beneath elevated welding activities.
5.3 POTENTIAL ACUTE HEALTH HAZARDS AND
Acute health hazards can impact individuals during or shortly after exposure, leading to effects that may be temporary or more enduring Generally, these short-term effects are reversible once the exposure ceases Common examples include eye irritation or respiratory issues resulting from brief inhalation of vapors, gases, or welding fumes Despite being transient, these effects are undesirable and should be prevented.
Hot work environments may pose acute hazards due to the presence of materials like hydrogen sulfide, chlorine, or ammonia, which can be released and endanger personnel Additionally, the welding process itself introduces health risks, such as eye irritation or burns from arc flash (ultraviolet radiation) and "metal fume fever" from fumes generated by vaporized zinc during the welding of galvanized steel Workers in these conditions are also at risk of heat stress and oxygen deficiency, both of which can have immediate and serious effects on health.
Understanding and mitigating hazards, and preventing exposure using proper protective equipment and good venti- lation are successful techniques for reducing risk during welding.
5.4 POTENTIAL CHRONIC HEALTH HAZARDS AND RISK REDUCTION
Chronic health hazards from welding arise from prolonged exposure to harmful materials, often showing effects long after the exposure has occurred The primary risk associated with welding fumes is linked to inhalation, making it crucial to focus on effective monitoring, proper ventilation, and the use of respiratory protection to mitigate these risks.
Noise is a common aspect of the welding work environment, necessitating careful attention to noise exposure and hearing protection, similar to other work settings Adhering to good practices and regulatory requirements is essential for safeguarding workers' hearing.
Some studies have related cataracts to chronic exposure to
UV radiation This possible effect reinforces the wisdom of using proper welderÕs eye protection.