Welding Cutting Heating

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Reference

HSE-TSSA-05-2011

Document Title

WELDING, CUTTING AND HEATING

SAFE WORK PRACTICES

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

Page 2 of 24

WELDING, CUTTING AND HEATING

SAFE WORK PRACTICES TABLE OF CONTENTS

PAGE

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Scope and Application.….………………………………………………………………..

3

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References…………………………………………………………………………………….

3

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Definitions…………………………………………………………………………………….

4

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Hazards, Precautions and Safe Work Practices 4.1 4.2 4.3 4.4 4.5

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Welding and Cutting Hazards ……………………………………………….. General Precautions …………………………………………………………….. Enclosure of Welding and Cutting Area ………………………………… Fire Watch Personnel …………………………………………………………… Personal Protection …..………………………………………………………….

6 7 9 10 11

Welding Works Classification and Requirements 5.1 5.2 5.3

Gas Welding and Cutting………………………………………………………. Electric Arc Welding and Cutting …………………………………………… Other Welding and Cutting Techniques ………………………………….

12 13 15

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Preheating and Heat Treatment (Stress Relieving) ……………………………

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Hot Tapping on Live Piping and Equipment ………………………………………

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Tie-in on Hydrocarbon Contaminated Lines ………………………………………

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Audit Requirements ……………………………………………………………………….

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APPENDIX Appendix - A

: Filter Lens Shade Numbers ………………………………………………..

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Appendix – B

: Flashback Arrestors and Hose Check Valves …………………………

21

Appendix – C

: Tarpaulin Canvass Cloth Selection Criteria…………………………….

22

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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SCOPE AND APPLICATION This document outlines the principles involved and the precautions to be taken in welding, cutting and heating work activities in KNPC premises. These activities are considered safe if they are carried out in a controlled manner by complying with the recommended safety precautions. The Safe Work Practices covered in this document include safety issues in gas and arc welding as well as flame cutting in detail. It briefly covers other modern cutting techniques such as hydrojet and plasma cutting. Reference for hot tapping and welding (including patch work and box welding) on live lines, tie-in on contaminated lines, and heat treatment have also been incorporated. The principles and resources provided in this document are widely applicable. Some activities may be subject to specific regulations or unique work requirements which should be considered when developing welding, cutting or heating program and activities. Personnel doing welding, cutting and other hot work require a high degree of skill and shall be qualified for the work they are doing. This document does not replace a welding manual. The qualification of personnel falls outside the scope of this document. Mandatory rules (or ‘must’) are characterized by the word ‘SHALL’ throughout the text. Advisory rules or recommendations are indicated by the word ‘SHOULD.

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REFERENCES • •

• • • • •

National Safety Council’s Accident Prevention Manual KNPC Inspection Procedure IC-18 (Inspection of Hot Tapping and Welding on Equipment and Piping), IC-23 (Welder Performance Qualification and Electrode Approval Procedure), IC-24 (Post Weld Heat Treatment for Piping) and IC-25 (Welding Manual) API RP 2201 (Safe Hot Tapping Practices in the Petroleum and Petrochemical Industries) API RP 2009 (Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries) OSHA 1910.252 Welding, Cutting and Brazing KNPC PPE Specifications KPC Document 49: Eye and Face Protection

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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DEFINITIONS Air-Tight Enclosure means that (a) sparks and molten metal/splatters are completely contained and (b) the natural air circulation is blocked which will contribute to an accumulation of toxic gas emanating from the electrodes or an inert condition caused by inert gas shielding process during welding and cutting works within the enclosure. Fire Watch is a person assigned in welding works to cover safety surveillance and response function on emergency situation, including first-aid fire fighting. First-Aid Fire Fighting is a practical training on the use of fire extinguishers, fire hose and couplings, foam making equipment, operation of plant paging and fire alarm call points, and use of other first-aid fire fighting equipment available in KNPC premises. Flameproof Tarpaulin Canvass is a cloth (glass fiber based or silica fiber based) used for welding work fire protection which does not burn or give off fumes when exposed to heat. Heating, Preheating or Heat Treatment terminology used in this document is referred to ‘stress relieving’ requirements for piping, valves and vessels before and after welding work. Stress relieving is used to avert or relieve the detrimental effects of the high temperature and severe thermal gradients inherent in welding of metals. Arc Welding: A group of welding processes which produces coalescence by heating them with an arc or arcs, with or without the application of pressure and with or without the use of filler metal. Gas Welding: A group of welding processes wherein a coalescence is produced by heating with a gas flame or flames, with or without the application of pressure, and with or without the use of filler material. Automatic Welding: Welding with equipment which performs the welding operation without adjustment of the controls by an operator. The equipment may or may not perform the loading and unloading of the work. Arc Cutting: A group of cutting processes wherein the severing or removing of metals is effected by melting with the heat of an arc between an electrode and the base metal. (Includes carbon-arc cutting, metal-arc cutting, ga metal-arc cutting, gas tungsten-arc cutting, plasma-arc cutting, and air carbon-arc cutting).

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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Oxygen Cutting: A group of thermal cutting processes that severs or removes metal by means of the chemical reaction between oxygen and the base metal at elevated temperature. The necessary temperature is maintained by the heat from an arc, an oxyfuel gas flame, or other source. Oxygen Gouging: Thermal gouging that uses an oxygen cutting process variation to form a bevel or groove. Oxygen-Arc Cutting: An oxygen-cutting process that uses an arc between the work piece and a consumable electrode, through which oxygen is directed to the work piece. For oxidation-resistant metals, a chemical flux or metal powder is used to facilitate the reaction. Soldering: A metal joining process wherein coalescence is produced by heating to suitable temperatures and by using a nonferrous alloy fusible at temperatures below 427C (800F) and having a melting point below that of the base metals being joined. Bracing: A metal joining process wherein coalescence is produced by use of a nonferrous filler metal having a melting point above 427C (800F), but lower than that of the base metals being joined. Shielded Metal-Arc Welding (SMAW): An arc welding process that produces coalescence of metals by heating them with an arc between a covered metal electrode and the work. Shielding is obtained from decomposition of the electrode covering. Pressure is not used and filler metal is obtained from the electrode. Gas Tungsten-Arc Welding (GTAW): An arc-welding process that produces coalescence of metals by heating them with an arc between a single tungsten (nonconsumable) electrode and the work. Shielding is obtained from a gas or gas mixture. Pressure may or may not be used and filler metal may or may not be used. (This process has sometimes been called TIG welding). Submerged Arc Welding (SAW): An arc welding process which produces coalescence of metals by heating them with an arc or arcs between a bare metal electrode or electrodes and the work. The arc is shielded by a blanket of granular, fusible material on the work. Pressure is not used and filler metal is obtained from the electrode and sometimes from a supplemental source (welding rod, flux, or metal granules). The terminology ‘welding works’ used in this document refers to welding, cutting and heating activities.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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HAZARDS, PRECAUTIONS AND SAFE WORK PRACTICES 4.1

Welding, Cutting and Heating Hazards

Welding, cutting and heating (herein after referred to as "welding work" for simplicity) activities involve many hazards as follows; 4.1.1 Fire hazard: Open flame, electric arc, molten metal, sparks or hot surfaces igniting flammable or combustible material. 4.1.2 Burn injuries caused by hot surfaces, sparks, slag or flame. 4.1.3 Health hazards: eye or skin exposure to ultraviolet (UV) and infrared (IR) radiation; inhalation of dust, toxic fumes such as oxides of Nitrogen (NOx), Carbon Monoxide (CO), Ozone, etc. and Oxygen deficiency. 4.1.4 Exposure to ultraviolet rays initially causes a painful and disabling but temporary form of conjunctivitis commonly known as "Arc eye". Looking directly into a powerful arc without eye protection can cause permanent eye damage. Ultraviolet affects the skin like severe sunburn. 4.1.5 Infrared radiation has the effect of heating the body tissues on contact. If the intensity of heat due to infrared is not enough to cause a thermal burn, there is no further hazard. 4.1.6 Hazards induced from preservative coatings on metal surface: The toxic hazard will depend on the, type of electrode used, the base metal being welded or cut, and whether the base metal is coated with flammable or toxic material (zinc, lead, paint, etc). 4.1.7 Ultraviolet rays can decompose some chlorinated hydrocarbon degreasing agents like Trichloroethylene, even at a considerable distance from the arc, to form highly toxic substances such as phosgene. 4.1.8 Oxygen Deficiency: In confined spaces, welding and cutting jobs may lead to oxygen deficient environment by consuming oxygen or displacing oxygen by inert gas. 4.1.9 Mechanical hazards: unguarded rotating parts, flying particles, high pressure water in hydrojet cutting, noise. 4.1.10 Compressed gas hazards (refer to relevant controlled SH&E document on Compressed Gas Cylinders Safe Work Practices) Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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4.1.11 Electric shock (refer to relevant controlled SH&E document on Electrical Safety) 4.1.12 Explosion Hazard: Welding of pipeline, vessel and tanks with improper opening and/or vent could lead to explosion due to heat generation. 4.2

General Precautions

4.2.1 When practical, objects to be welded, cut or heated shall be moved to a designated safe location or, if the object cannot be readily moved, all movable fire hazards in the vicinity shall be taken to a safe place or otherwise protected (e.g. using flame retardant barricades, covers, blinding, etc). 4.2.2 If the object cannot be moved and all the fire hazards cannot be removed, positive means shall be taken to confine the heat, spark, and slag to protect the unmovable fire hazard, from these. 4.2.3 The following welding equipment safety shall be strictly enforced: a) All welding equipment shall be properly maintained, regularly inspected by using a checklist (i.e. as per operating procedure), and shall have valid Safety Certificate. b) Two fire extinguishers (9 kg. DCP) shall be provided with each welding equipment, one to be kept at the work and the other at the machine. Plant extinguishers shall not be used for this purpose c) Welding equipment shall be parked outside the battery limit whenever possible and when parked, it should be provided with wheel stoppers to prevent any movement. d) Location of welding equipment and laying of cables should not obstruct regular activities. All cables should be joint-free. e) Earthing should be nearest to the welding point. It should be through nearby designated pit. In case there’s no earth pit nearby, structures may be used as earthing, but in no case a product pipeline will be used as earthing. 4.2.4 Welding work in a Restricted Area shall be done after obtaining a Hot Work Permit and all requirements pertaining to hot work shall be enforced such as the Hot Work Risk Assessment for critical welding jobs in hazardous areas.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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4.2.5 The welder shall not work alone. The welder and helper must be trained on First-Aid Fire Fighting by KNPC / Contractor Fire Fighting Trainers. A training card (similar to Fire Watch card) shall be issued. 4.2.6 When welding work is carried out in a workshop or any similar location classified as a permit free area, which is approved by KNPC Safety, a work permit is not required but the work shall be adequately supervised. The requirement for Fire Watch shall be mandatory unless exemption is defined from a Risk Assessment Report. 4.2.7 Degreasing operation and other works using chlorinated solvents shall be located away from welding work area. Protective coating other than weldable primers on metal shall be removed before start of welding or heating. 4.2.8 Welding work on any tank, vessel or piping shall only be undertaken when it has been positively isolated from all sources of flammable hazards and established that it is free of flammable vapors or substances. (Refer to related procedures and guidelines on Blinding, Work Permit, Entry, and Gas Test requirements). 4.2.9 While welding on positively isolated short pipes, wedge opening should be provided towards the pipe to be welded or nearer to the welding joint. 4.2.10 When cutting a long process pipe, where a gas test cannot be performed close to the point of cut, a cold cut test hole shall be drilled from top of pipe and flammable gases tested. If trapped liquid is suspected, a second hole may be drilled from the bottom. Similarly, before cutting the bottom plate of a tank, gas test shall be made through test holes. 4.2.11 Steps shall be taken to contain and/or quench the sparks. Welded components retain heat for a period of time after the job is completed. Such components shall be marked hot and kept cordoned off until sufficiently cooled to avoid burn injury or fire. 4.2.12 Above or nearby surfaces contaminated by hydrocarbons or other potential fuels (including wrapping, coating or other combustible materials) shall be (a) wiped clean and flushed with water, or (b) steam cleaned, or (c) covered with clean dirt or sand, or (d) protected by other precautions which isolate fuel contaminated surfaces from ignition sources. 4.2.13 Holes in the ground or open sewers or cracks in pavement should be protected in a manner similar to hydrocarbon contaminated surfaces by flushing and covering. 4.2.14 All sewers and catch basins on 15 meters from the work area shall be covered, plugged, isolated or secured (a) to prevent hydrocarbon vapors from exiting the sewer or drain and reaching an area of hot work and (b) to prevent Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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sparks/molten metal from getting into the sewer . A catch basin equipped with a trap should be flushed continuously with water. 4.2.15 Good housekeeping shall be maintained at work site. The welding work area shall at all times be kept clean of combustible and flammable material. Used welding rods, grinding discs, etc. shall be collected and not thrown around. 4.2.16 Welding works shall be stopped immediately as and when instructed by the area custodian of concerned operating personnel or during any other emergency / MIPP situation. 4.2.17 Every possible precaution should be taken with jacketed vessels, tanks or containers to vent them sufficiently before doing any hot work. 4.3

Enclosure of Welding and Cutting Area

Welding and cutting works at KNPC premises generally require the protection of equipment and surrounding area from damage or fire ignition from the hot work activity. This activity includes oxy-fuel metal cutting, light duty welding, heavy duty welding and arc gouging. The following requirements shall be strictly enforced: 4.3.1 The welding and cutting area must be totally enclosed, using a flameproof tarpaulin canvass in a manner to contain sparks, molten metal/splatters, block the view of the welding/cutting arc from passerby, and isolate any nearby combustible fuel source from the hot work activity. 4.3.2 The material of flameproof tarpaulin canvass shall be made from silica or glass fibers which have low off gassing and which may melt (but not burn) when contacted by flames, welding slag or splatter. Refer to Appendix-C for the guidelines in the selection criteria for flameproof tarpaulin canvass. 4.3.3 Regular checks shall be carried out (by the Work Permit Executor) to determine the condition of the flameproof tarpaulin canvass (e.g. if charred, ripped, torn, melted areas with holes, etc.). The canvass shall be replaced when the damage is sufficient enough to potentially exposed equipment surfaces or whenever molten metal / sparks can not be totally contained. 4.3.4 For heavy and extreme duty operations of arc gouging and flame cutting in the running process units and piping, sheet metal shall be placed under the fire stream to lessen the chances of the molten metal melting through the flameproof tarpaulin canvass. The sheet metal should be supported 51 mm (2 inches) above the flameproof tarpaulin canvass. 4.3.5 The tarpaulin canvass enclosure, whenever required to be air-tight particularly in the running process units and piping, shall be categorized as a Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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confined space wherein all terms and conditions related to Confined Space Entry Safe Work Practices must be applied. 4.4

Fire Watch Personnel

Work Permit Executor shall provide properly trained and equipped ‘fire watch’ personnel for welding and cutting works in running process units, pipe rack or in any product pipe area. The person assigned as a fire watch shall have no other duties that would distract from the primary safety surveillance and response function. The fire watch person may do other safety-related task if the primary fire watch responsibility is not compromised. The fire watch personnel must wear a special vest (orange with FIRE WATCH print at the back) with their name and employee number written in the Work Permit. 4.4.1 The fire watch personnel equipment and knowledge shall include: (a)

Understands and capable to recognize hazards.

(b) Have appropriate functional fire extinguishing equipment readily available. (c)

Trained and certified in the equipment’s use and first-aid firefighting. Respective KNPC / Contractor’s Fire Fighting Trainers shall train and certify the fire watch.

(d) Familiar with facilities for sounding an alarm in the event of a fire. (e)

Capable to communicate effectively with the workforce.

4.4.2 The fire watch personnel should understand his duties which include the following: (a)

Shall continuously monitor and watches for fires in all exposed areas.

(b)

Shall remain within 8 meters radius of work vicinity during welding / cutting until relieved by another fire watch.

(c)

Shall maintain assigned suppression equipment within close proximity

(d)

Shall be aware on the location and how to activate the nearest fire alarm.

(e)

Shall activate the fire alarm when available equipment is not sufficient to suppress minor fire.

(f)

Shall try to extinguish a fire only when obviously within the capacity of the available equipment.

(g)

Shall maintain a watch for at least ½ hour after completion of welding and cutting works until the area has been inspected and found to be free of leaks and ignition sources (fires, hot spots or smoldering materials).

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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Personal Protection

The items and requirements included in this document are described in more detail in other Company SH&E guidelines and Safe Work Practices such as the Respiratory Protection Program under Occupational Health, Safety Guidelines for Personal Protection Equipment, PPE Specifications, etc. 4.5.1 Respiratory Protection (a)

In confined spaces such as tanks, pressure vessel, large diameter pipelines, confined enclosures, etc., local exhaust or general ventilation system shall be provided to remove toxic gases, fumes, etc. and to maintain oxygen concentration above 19.5%. Pure oxygen shall not be used for ventilation.

(b)

Local exhaust hoods shall be provided in welding shops or indoor enclosures. Local exhaust should be achieved by means of movable hood placed as near as possible to the welding job, and provided with an air flow rate sufficient to maintain a velocity of 100 fpm (ft./minute) at the point of welding in the direction of the hood. General ventilation can be achieved by providing mechanical ventilation at a minimum rate of 2000 cfm (cu. ft./ minute) of air per welder, or four air changes per hour, whichever is greater.

(c)

Where gases, dust and fumes cannot be maintained below TLV or for any other reason, welders shall wear canister/cartridge mask suitable for fumes. In confined spaces where hazard of oxygen deficiency may exist, airline mask shall be used.

4.5.2 Eye Protection (a)

Goggles or shields fitted with correct filter lens shall be used during welding and cutting operations to protect the eyes from light and ultraviolet / infra red radiation. (see Appendix-A for lens selection).

(b)

During welding eye protection shall be used by welder and his helper.

(c)

Welder's Goggles shall be used when grinding, chipping, de-slagging and during gas welding (KNPC Spec PPE/WP/03). Arc welder shall wear welder's shield. Safety glasses without side shield shall not be worn in any case.

(d)

Screens (refer Appendix-C for the Tarpaulin Canvass Cloth Selection Criteria) shall be provided around welding and cutting jobs to protect other persons from exposure to direct or reflected ultraviolet rays.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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Protective Clothing and other PPE

(a)

Fire retardant coveralls (KNPC spec. PPE/PC/02) and apron (KNPC spec. PPE/WP/05) shall be worn by welders and fabricators. These protective clothing shall be kept free of oil and grease and shall have the sleeves and collars kept buttoned up for protection against ultraviolet and infrared radiation.

(b)

Sleeves and collars of coveralls shall be kept buttoned up for protection against Ultraviolet and Infrared radiation.

(c)

Gauntlets or gloves made of leather or flame resistant material shall be used to protect hands from burns (KNPC spec. PPE/WP/04).

(d)

Welder’s safety boots (KNPC spec. PPE/HP/04) shall be used for protection against heavy objects and sparks.

(e)

For overhead work, caps or shoulder cover and skullcaps made of leather or suitable flame resistant material shall be used to prevent burn injuries. During overhead welding, ear protection is recommended against falling sparks.

(f)

In plant areas and when the hazard of head injury exists due to falling objects, etc., Welder's hood (KNPC Spec PPE/WP/02 - a safety hat fitted with welding mask) shall be used.

WELDING WORK CLASSIFICATION AND REQUIREMENTS 5.1

Gas Welding and Cutting

5.1.1 Gas welding and cutting operations utilize the heat of the flame obtained from the combustion of a fuel gas with oxygen. Oxygen is normally supplied in cylinders containing 244 cu. feet of oxygen at a pressure of 2200 psig at 70ºF. Acetylene is supplied in cylinders and dissolved in acetone over a porous material at a pressure of 250 psig at 70ºF. Acetylene cylinders normally contain 300 cu. ft. of acetylene. Acetylene is explosive in a concentration range of 2% to 82% in air and therefore requires careful handling. 5.1.2 Refer to Compressed Gas Cylinders Safe Work Practices for the safety precautions related to storage, handling and use of cylinders and its fittings (regulators, gauges and hoses). 5.1.3 Acetylene gas becomes unstable at pressures above 15 psig and therefore acetylene regulator pressure shall not be allowed to exceed 15 psig. Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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5.1.4 Acetylene cylinders shall be stored, handled and used in vertical position to avoid liquid acetone from escaping and damaging down-stream equipment. If LPG is used as a fuel gas for cutting purpose, industrial type cylinders shall be used. 5.1.5 All cylinders shall be kept vertical and secured either in a cylinder trolley or floor support or lashed to a fixed support. Cylinders shall not be located in any enclosed space where welding or cutting job is taking place. Oxygen and acetylene cylinders shall be kept at least 15 ft. away from the blowtorch or any other source of ignition. 5.1.6 Flash back arrestors and hose check valves shall be fitted to both oxygen and fuel gas regulators (see Appendix-B). 5.1.7 Spark lighters shall be used to light torches. Matches and smoldering rags shall not be used. 5.1.8 Cylinders shall not be transported with the regulators and hose attached, except on a purpose made trolley. 5.1.9 Oxygen and acetylene hoses shall be of different colors or otherwise identified and distinguished from each other. Maroon is generally used for acetylene and black for oxygen. 5.1.10 The blowtorch when lighted shall not be placed on or near cylinders, regulators and hoses. Before changing the torch, shut-off the gas at the pressure reducing regulators (not by crimping the hose). 5.1.11 When extinguishing the flame, shut-off the acetylene first by closing the torch control valve. Only exception to this is when a backfire occurs in the mixing chamber where oxygen to be shut off first to stop burning internally. 5.1.12 The blowtorch and hose, when not in use, shall not be left unattended in any confined space even for short period, e.g., lunch break. Torch shall be taken out or alternatively, oxygen and acetylene connections shall be disconnected from the cylinders located outside confined space. Closing of cylinder valves shall not be treated as disconnection. 5.1.13 Cylinder valve wrench should be left in place on the cylinder when in use. 5.2

Electric Arc Welding and Cutting

5.2.1 Engine of welding machine shall be stopped during refueling. Guards of rotating parts shall be kept in place. Welding machine shall be kept 15 meters away from sources of flammable hazards. Exhaust shall not be allowed to enter confined spaces. It shall be provided with reflective sticker or warning light if left by roadside during dark hours.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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5.2.2 All welding leads and returns shall consist of flexible tough rubber covered cables, robust enough to withstand normal treatment over rough ground and pedestrian traffic. Where feasible, cables should be additionally protected by stringing overhead or by using cable covers. 5.2.3 The insulation of cables, electrode holders, plugs and sockets shall be regularly inspected for visible damage and discarded if necessary. If cables are to be joined together for additional length, proper cable connectors shall be used ensuring that no live conductor is exposed. 5.2.4 Each welder, in addition to earth bonding, shall have a separate return lead to his set. The protective earth connection shall not be used to carry welding current. The lead shall be connected to the job as near to the point of welding as possible. It shall not be hooked to other process lines or structure of pipe rack. 5.2.5 Testing of the welding rod should be done using a testing plate and not by arcing on the existing structure or piping. 5.2.6 Welding grounds and returns shall be securely attached to the work by cable lugs, (or clamps) in case of stranded conductor or by bolts for strip conductors. Bolts shall not be used for stranded conductors. 5.2.7 When butt welding of two items is to be done and neither item is permanently attached to any structure, both items shall be connected to the welding return. This is necessary to prevent stray current causing sparks at a distance away from welding point. 5.2.8 Handle of electrode holder shall be made of non flammable insulating material and be free of joints or holes. A guard disc of similar material shall be fitted between electrode holder and handle or similar material covering of electrode holder shall be provided to prevent live elements from being touched. Electrode holders shall be suitable to accommodate all sizes of electrodes and should have an ejector for spent stubs. 5.2.9 Electrode holders shall not be placed on the ground when not in use, Instead, it should be hanged or secured to prevent sparking. Cooling hot electrode holders by dipping in water shall be prohibited. 5.2.10 The cable shall have adequate current carrying capacity to meet the job requirement. 5.2.11 Welding return lead shall be provided from the neutral terminal of each phase of an arc welding transformer, or the negative terminal of a DC Generator to the work piece. 5.2.12 When more than two welders are using the same welding machine, the polarity of each welding lead and return shall be the same. Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

Printed Copy Not Controlled KUWAIT NATIONAL PETROLEUM COMPANY

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5.2.13 When welding work is not in progress, even for a short period, the power source of the welding circuit shall be disconnected. 5.2.14 For all AC welding transformers low voltage winding shall not be earthed, but the transformer case shall be effectively bonded to an earthing system adjacent to the equipment. 5.2.15 For all AC driven DC welding generators, no earth connection shall be applied to either pole of the DC welding output. The machine frame shall be effectively earthed. 5.2.16 For engine driven DC welding generators earth connections shall not be applied to generators output terminals. 5.2.17 In case of gas-shielded arc welding and when water is used for cooling, the water supply line shall be equipped with a strainer to keep out impurities which might get into the torch and plug the water cooling passages. 5.2.18 The power supply plugs, receptacles and extension cords shall meet standard requirement such as KNPC Intrinsic Safety for hazardous area locations, GFCI protection, correct polarity, having approved voltage and ampere ratings that are compatible with their intended use, protected against physical damage, etc. 5.2.19 Welding transformers shall not be attached to lighting circuits under any circumstances. 5.3

Other Welding and Cutting Techniques

5.3.1 Soldering should be done in a well-ventilated areas. Workers shall wear safety glasses. The major hazards of soldering are heat, fumes, and the lead content of the solder. The soldering iron or gun will have a temperature range of 180 – 340 °C (360 to 650 °F). This can cause severe localized burns if handled improperly. The molten metal can also be a potential hazard. The fumes produced during the soldering process can be a health hazard depending on what materials caused the fumes. Some materials used as insulation around conductors, when subjected to high heat, will produce toxic fumes. When the soldering task has been completed, hands should be washed thoroughly with soap and water. 5.3.2 Brazing is the process of joining metals using non-ferrous filler metal such as copper. Adequate ventilation, goggles and other protective for hot materials are required. 5.3.3 Thermit(e) Welding is used to attach electrical cables anodes, etc. This reaction process joins metals by heating with superheated liquid metal with or Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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without pressure. Personnel should wear face shield and other welder clothing to protect from hot metal particles or sparks. 5.3.4 Plasma Cutting uses a 'plasma' (a gas heated until ionized) to conduct current. Molten metal is blown away by the hot gas. Plasma cutting generally requires the precautions similar to Arc Cutting. The crew shall wear hearing protection. Plasma arc cutting torches are typically designed with safety interlock systems that turn off the machine if operators loosen the shield cup or if the tip touches the electrode inside the nozzle. However, plasma arc cutting requires higher voltages than welding to start and maintain the arc, typically 110 to 400 V DC, and touching live electrical parts can cause fatal shocks or severe burns. Poor connections and bare spots on cables increase the possibility of electrical shock. These items shall be inspected daily and replace, not repair, any worn cables or broken connections. Machine Operators must routinely inspect for effective ground connections. Connect the frames of all electrically powered machines to a properly grounded disconnect switch, receptacle or other appropriate ground. Always double-check the installation and verify proper grounding. 5.3.5 Hydrojet Cutting. Personnel shall be protected from direct or indirect hit by high-pressure water jet. Area around the cutting nozzle shall be barricaded with metal sheets. Personnel shall wear face shield. Hoses and couplings shall be checked before each job. Wastewater contaminated with abrasive metal shall be disposed properly.

6.0

PREHEATING AND HEAT TREATMENT (STRESS RELIEVING) Safe work practices herein defined shall be cross-referred to terms and conditions on IC-24 (Inspection and Corrosion Procedure for Stress Relieving). Preheating and Heat Treatment requirements for piping, valves and vessels before and after welding are used to avert or relieve the detrimental effects of the high temperature and severe thermal gradients inherent in welding of metals. Precautionary measures on possible electric shock, moving parts, and hot parts hazards shall be appropriately addressed, which include but not limited to the following: 6.1

Electric Shock Hazard Precautions

Touching live electrical parts can cause fatal shocks or severe burns. The power circuit and output bus bars or connections are electrically live whenever the output

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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is on. The input power circuit and machine internal circuits are also live when power is on. The machine should be correctly installed or properly grounded. 6.1.1 All connecting bus bars and coolant fittings should be enclosed to prevent unintentional contact. 6.1.2 Dry, hole-free insulating gloves and body protection shall be worn. 6.1.3 Employee shall be insulated from work and ground by the use of dry insulating mats or covers big enough to prevent any physical contact with the work or ground. 6.1.4 Nonconductive coolant hoses with a minimum length of 457 mm (18 inches) to provide isolation shall be used. 6.1.5 Equipment shall be properly installed and grounded. Equipment operator shall always verify the supply ground and ensure that input power cord ground wire is properly connected to ground terminal in disconnect box or that cord plug is connected to a properly grounded receptacle outlet. 6.1.6 All panels and covers shall be securely kept in place. 6.2

Fire or Explosion Hazard Precautions

6.2.1 The unit shall not be operated in explosive atmosphere 6.2.3 The unit shall not be installed near flammables. All flammable materials shall be kept away (15 meters) from work area. 6.2.4 The unit shall not be located on, over, or near combustible surfaces. 6.2.5 Fire Watch shall be assigned along with a standby fire extinguisher 6.3

Fumes and Gases Hazard Precautions

6.3.1 Heating of certain materials, adhesives, and fluxes can produce hazardous fumes and gases. Appropriate respiratory protections should be used. Always refer to Material Safety Data Sheet (MSDS) and the manufacturer’s instruction for adhesives, fluxes, metals, consumables, coatings, cleaners, and degreasers. 6.3.2 Heating shall not be permitted near degreasing, cleaning, or spraying operations. The heat can react with vapors to form highly toxic and irritating gases. 6.3.3 During heat treatment work in a confined space, fumes and gases from heating can displace air and lower the oxygen level causing injury or death. Safe work practices for confined space entry shall be followed with continuous gas monitoring.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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6.3.4 Coated metals should not be overheated, such as the galvanized, lead or cadmium plated steel, unless the coating is removed from the heated area, the area is well ventilated, and if necessary, while wearing an air-supplied respirator. The coatings and any metals containing these elements can give off toxic fumes if overheated. Whenever required, refer to relevant coating MSDS for temperature information.

7.0

HOT TAPPING AND WELDING ON LIVE PIPING & EQUIPMENT In certain circumstances, welding is allowed on live lines and tanks due to difficulty in depressurizing and getting freed of flammable material. Welding work on live pipelines and equipment includes welding of stubs on lines or vessels prior to drilling for hot tap, welding brackets on tanks, patchwork and box welding. Such work requires extra precautions in addition to normal hot work precautions. Risk assessment shall be carried out for all hot tapping and welding on live piping and equipment. Inspection Procedure IC-18: "Hot Tapping & Welding on Equipment and Piping" Procedures and requirements shall be strictly enforced. Hot tapping shall be considered as a last resort and every effort shall be made to weld the tie-ins during shutdown. Immediately prior to commencement of welding on live equipment, the issuing authority shall ensure that safe conditions for carrying out the job have been established. Hot tapping and/or Welding Authorizations (as per IC-18) shall be available with the permit. Issuing authority shall himself be present at the start of the job and thereafter keep in close touch at frequent intervals. Executing authority shall continuously supervise the job.

8.0

TIE-IN ON HYDROCARBON CONTAMINATED LINES A tie-in on hydrocarbon contaminated line involves the hazard of hot work on lines which have been taken out of service but cannot be entirely freed of gas or oil. This type of work includes work on flare lines or long, large diameter lines which cannot be easily cleaned. This work is normally carried out on open-ended lines, which will need to be blinded and possibly plugged by means of an expanding plug to isolate a small portion of the line near the point where the hot work is to be done. A plug should be fixed at a minimum distance of ‘½ meter’ from the point of hot work and should be of an expanding type so as to make a tight seal. If possible the space above the plug should be filled with water before welding. The space behind the plug shall be vented to a safe location to avoid a pressure build-up.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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Other normal welding precautions for hazardous area, as described in previous sections, shall be followed.

9.0

AUDIT REQUIREMENTS Compliance on the complete implementation of this guideline shall be regularly audited through the existing audit and inspection programs such as in the ‘Safety Performance Audit’ and ‘Work Permit Compliance Audit’ that is being carried out by the management team and Safety Section.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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KUWAIT NATIONAL PETROLEUM COMPANY

APPENDIX-A GUIDE FOR SELECTION OF LENS SHADE SHADE NUMBERS ARE GIVEN AS A GUIDE ONLY AND MAY BE VARIED TO SUIT INDIVIDUAL NEEDS ELECTRODE SIZE inches (mm.)

ARC CURRENT (Amperes)

Minimum Protective Shades

* Suggested Shade No. (Comfort)

Less than 3/32 (2.4) 3/32-5/32 (2.4-4.0) 5/32-1/4 (4.0-6.4) More than ¼ (6.4)

Less than 60 60-160 160-250 250-550

7 8 10 11

10 12 14

Gas Metal Arc Welding (GMAW) and Flux Cored Arc Welding (FCAW)

Less than 60 60-160 160-250 250-500

7 10 10 10

11 12 14

Gas Tungsten (GTAW)

Less than 50 50-150 150-500

8 8 10

10 12 14

Less than 500 500-1000

10 11

12 14

Plasma Arc Welding (PAW)

Less than 20 20-100 100-400 400-800

6 8 10 11

6 to 8 10 12 14

Plasma Arc Cutting (PAC)

Less than 20 20-40 40-60 60-80 80-300 300-400 400-800

4 5 6 8 8 9 10

4 5 6 8 9 12 14

Torch Brazing (TB)

-

-

3 or 4

Torch Soldering (TS)

-

-

2

Carbon Arc Welding (CAW)

-

-

14 * Suggested Shane No. (Comfort)

PROCESS Shielded (SMAW)

Metal

Arc

Arc

Welding

Welding

Air Carbon Arc Cutting (CAC-A)

(Light) (Heavy)

PLATE THICKNESS inches mm Oxyfuel Gas Welding (OFW) Light Medium Heavy Oxygen Cutting (OC) Light Medium Heavy

Under 1/8 1/8 to ½ Over 1/2

Under 3 3 to 13 Over 13

4 0r 5 5 or 6 6 or 8

Under 1 1 to 6 Over 6

Under 25 25 to 150 Over 150

3 or 4 4 or 5 5 or 6

* As a rule of thumb, start with a shade that is too dark to see the weld zone. Then go for a lighter shade which gives sufficient view of the weld zone without going below the minimum. In oxyfuel gas welding or cutting where the torch produces a high yellow light, it is desirable to use a filter lens that absorbs the yellow or sodium line in the visible light of the (spectrum) operation. Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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APPENDIX-B: FLASH BACK ARRESTORS AND HOSE CHECK VALVES

Acetylene (Maroon Color Cylinder)

Oxygen (Black Color Cylinder)

Gas welding equipment showing positions of flashback arrestors and hose check valves

1 Normal gas flow from regulator 2 To hose and blowpipe 3 Back-fed gas 4 Two-way cut-off halts flow in both directions and remains closed even if pressure increases 5 Cut-off opens lever revealing red indicator 6 Pressure relief valve allows gases to escape 7 Sintered metal flame trap

Normal Flow

Back Pressure

Operation of Flash Back Arrestor

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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APPENDIX - C

TARPAULIN CANVASS CLOTH SELECTION CRITERIA This reference provides generic guidelines on the cloth selection and typical applications of flameproof tarpaulin canvass that is generally required in the protection of equipment and surrounding area from damage or fire ignition from the hot work activities. C.1

Tarpaulin Canvass Cloth

Basically, there are two classes of cloths used for welding fire protection today. One is glass fiber based (fiberglass) , the other is silica fiber based. The difference between the two is temperature rating. Fiberglass is rated at 538 °C (1000 °F) whilst silica is rated at 982 – 1093 °C (1800 – 2000 °F), plus a 538 °C (3000 °F) melting temperature. Coatings are used to enhance the cloth’s duty performance or it’s resistance to moisture. Some coatings such as neoprene will burn and give off fumes (off gassing). It is usually best to not use coated materials as the coatings can also char making the cloth brittle to handle and create air-borne fibers. All cloths will become brittle to handle given enough exposure to heat. As the cloth can be woven into different weave patterns and use different size strands, the cloth can highly varied in thickness or closeness of weave pattern. The thickness and how tightly the cloth is woven affects its performance to resist tearing., abrasion, molten metal sprays and droppings, or thermal protection from radiant energy of the welding arc or torch. Typical cloth thickness ranges from 0.017 inch to 0.6 inch and can be supplied in roll or blanket or canvass forms. Blankets / canvass are cut to size from rolls and may be hemmed and grommets installed for hanging the blankets / canvass. Rolls are typically 40 inches to 60 inches wide (some can be 120 inches) by 50 yards in length. Thickness and weight give an indication of robustness, but are not the only factors in choosing the correct cloth for the application. Some cloths abrade easily, others do not. The coated products do better than the non-coated under abrading conditions such as heavy traffic floors or scaffolding. Coated products can be used to protect vertical surfaces where any weld splatter will tend to bounce off. Vermiculate is used in the coating to raise the temperature rating of fiberglass cloths. Neoprene and silicone rubber coatings impart strength and stiffness as well as capturing the fibers when cut or abraded. Some cloths are very slick and can cause a slipping hazard. Other cloths are easily cut when placed over sharp metal edges. The many grades of cloth are manufactured by several textile mills around the world. The cloth is usually sold by distributor under brand names rather than mill identification and product number. The same mill product may have several different brand names, making it difficult to specify for purchase. It is best to examine and test the cloth before Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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KUWAIT NATIONAL PETROLEUM COMPANY

purchasing to assure good performance in practice. Testing can be as simple as exposing the cloth to an open flame to see if it will burn. Other tests can be arc gouging steel and directing the molten metal at the cloth in the position the cloth will be used (e.g. down flat, vertical, etc.). C-2

Tarpaulin Canvass Cloth Selection Criteria Per Application MINIMUM THICKNESS

MINIMUM LAYERS

Fiberglass (Non-coated)

0.03 inch

1

SMAW, GMAW and FCAW welding at more than 150 to 250 amps. Light grinding to remove weld crown or defects. No arc gouging or flame cutting. No open flame preheating.

Fiberglass (Non-coated)

0.03 inch

• 1 for vertical surfaces

GMAW, FCAW and SMAW welding in excess of 250 amps. Heavy grinding to remove weld crown or defects. Light limited arc gouging. Molten metal spray directed away from the tarpaulin canvass cloth unless two (2) layers are used. Limited flame cutting with molten metal and hot parts restricted to falling on steel sheet to protect the cloth from seeing high temperatures. No open flame preheating.

Silica

Arc gouging or flame cutting such that molten metal will fall or be blown onto the cloth. Heavy grinding to remove dross or to cut through existing piping or structural. Open flame preheating such that the flames could contact the cloth or be exposed to the heat for long periods.

Silica

DUTY

DUTY DESCRIPTION

CLOTH TYPE

Light

GTAW, GMAW, FCAW and SMAW welding at 150 amps or less. Light grinding to remove weld crown or defects. No arc gouging or flame cutting. No open flame preheating.

Medium

Heavy

Extreme

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

•2 for surfaces 0.03 inch

• 1 for vertical surfaces •2 for surfaces

0.05 inch

flat

flat

• 1 for vertical surfaces •2 for surfaces

flat

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012

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Notations: (a)

It is preferable that two (2) layers should be used at 90 degrees to each other with 2 inches minimum laps to lessen the chances of the laps opening up during welding, grinding or cutting operations which will subsequently expose the equipment surfaces or a means for molten metal or sparks escaping out of the work enclosure.

(b)

Several layers of thinner material can be used in lieu of one minimum thickness cloth.

(c)

Top layers shall be monitored closely for replacement, especially those applied to flat surfaces which see a lot of splatter or falling slag.

(d)

For the heavy and extreme duty operations of arc gouging and flame cutting, sheet metal shall be placed under the fire stream to lessen the chances of the molten metal melting through the multi-layer tarpaulin canvass thickness. The sheet metal shall be supported about 2 inches above the tarpaulin canvass.

(e)

Once the tarpaulin canvass has been installed, regular checks shall be made to determine its condition (charred, ripped, torn, melted areas with holes, etc.). Replace the tarpaulin canvass when the damage is sufficient enough to potentially expose equipment surfaces or when molten metal or sparks can not be totally contained.

Reference: SHE-TSSA-05-2011 / Rev.- 3 Date of Issue: November 2009

Title: Welding, Cutting and Heating Safe Work Practices Next Review Date: November 2012