Гричин С.В., Ульянова О.В. - Английский язык для инженеров сварочного производства (1044906), страница 18
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Exposure must bereduced as far as is reasonably practicable and at least below any MEL.An OES is the concentration of an airborne substance, for which (accordingto current information) there is no evidence that it is likely to cause harm to aperson's health , even if they are exposed day after day. Control is thought tobe adequate if exposure is reduced to or below the standard.The OESs and the MELs of some of the substances found in weldingfume are listed in Table below; the absence of other substances from this listdoes not indicate that they are safe.98Chart 2Occupational Exposure LimitsSubstances Assigned a Maximum ExposureLimit8hr TWABeryllium0.002mg/m 3Cadmium oxide fume (as Cd)0.025mg/m 315 minSTEL0.05 mg/mChromium VI compounds (as Cr)3Cobalt0.1 mg/m 3Nickel (insoluble compounds)0.5 mg/m 3Substances Assigned an OccupationalExposure StandardWelding fume5 mg/m 3Fluoride (as F)2.5 mg/m 3Iron oxide, fume (as Fe)5 mg/m 310 mg/m 3Zinc oxide, fume5 mg/m 310 mg/m 3Manganese, fume (as Mn)0.5 mg/m 3Ozone0.2 ppmNitric Oxide1 ppmNitrogen dioxide1 ppmChromium III compounds (as Cr)0.5 mg/m 3Barium compounds, soluble (as Ba)0.5 mg/m 3Carbon monoxide50 ppmCopper fume0.2 mg/m 3300 ppmIf the fume contains only substances such as iron or aluminium whichare of low toxicity, an 8 hour (TWA) OES of 5mg/m3 applies; this figure isthe average concentration of particulate fume that should not be exceeded inan 8 hour day.99The Control of Substances Hazardous to Health (COSSH) Regulations2002 require employers to monitor the safe use of chemicals and hazardoussubstances at work.
It requires them to: control exposure to hazardoussubstances to prevent ill health both now and any future cumulative effectsthey may have, protect both employees and others who might be exposed,compile records of employees using these materials, supply employees withsuitable personal protective equipment.Vocabularyirritationrespiratory tractsusceptibilityfeverticklingchest tightnessflucoughinglimbsiderosispneumoniapulmonaryoedemaasphyxiationexposurecancer3раздражениедыхательные путиЧувствительность, восприимчивостьжар, лихорадка; какое-л.
заболевание, основнымсимптомом которого является очень высокаятемпературапершение (в горле)стесненное дыханиегриппкашельконечность (человека или животного)сидерозвоспаление легких, пневмонияотек легкихудушьеподвергание какому-л. воздействию; выставление,оставление на солнце, под дождем и т. п.ракRead the text carefully and answer the following questions.1.
What is the difference between welding fume and welding gas?2. What does the major part of the particulate fume arise from?3. What does the degree of risk to the welder's health from fume or gasesdepend on?4. Under what condition is control over the exposure of welders to hazardousfumes or gases considered adequate?5. Do the COSHH Regulations state only single substances?1004Say if the following is true or false. Correct the false sentences.1.
The smaller the particles the more harmful the fume is.2. The risk to the welder's health from fume or gases depends on the weldingarc.3. Welders have lung cancer more often than the general population.4. Asphyxiation may happen due to inadequate ventilation.5.
Metal fume fever is an incurable illness.5Complete the following sentences.1. Argon is a … gas.2. Particulate fume is very … for man’s health.3. When exposed to particulate fume of high concentration for a long time, awelder may … .4. Welding galvanised steel may cause … .5. Asphyxiation may happen due to … .6. To minimise the risk, special attention should be paid to controlling fumeswhich may contain chromium or … compounds.7.
In case of metal fume fever, …. recovery occurs soon after removal of thewelder from the exposure.8. … is a disease caused by fluid on the lungs.9. MEL means maximum … limit.10. OES is … exposure standard.11. Gases encountered in welding are … .Reading 26Read the text Safety and Scheduled Maintenance Protect YourWelding Assets and say if you follow all the instructions during welding.Safety and Scheduled Maintenance Protect Your Welding AssetsQ: What can I do to avoid electrical shocks?A: Wet working conditions must be avoided, because water is an excellentconductor and electricity will always follow the path of least resistance.
Evena person's perspiration can lower the body's resistance to electrical shock.Poor connections and bare spots on cables further increase the possibility ofelectrical shock, and therefore, daily inspection of these items isrecommended. Equipment operators should also routinely inspect for properground connections.101Q: How can I inspect and maintain my wire feeder?A: Periodically inspect the electrode wire drive rolls. If dirty, remove thedrive rolls and clean with a wire brush. Deformed drive rolls should bereplaced.
Drive rolls should be changed, adjusted or cleaned only when thewire feeder is shut off. In addition, check the inlet and outlet guides andreplace if they are deformed from wire wear. Remember that when power isapplied to a wire feeder, fingers should be kept away from the drive roll area.Q: What are some important electrode safety considerations?A: Welding power sources for use with MIG and TIG welding normally areequipped with devices that permit on/off control of the welding power output.If so, the electrode becomes electrically hot when the power source switch isON and the welding gun switch is closed.
Never touch the electrode wire orany conducting object in contact with the electrode circuit, unless the weldingpower source is off. Welding power sources used for shielded metal arcwelding (SMAW or Stick welding) may not be equipped with welding poweroutput on/off control devices. With such equipment, the electrode iselectrically hot when the power switch is turned ON.Q: How should I store my gas cylinders?A: Cylinders should be securely fastened at all times. Chains are usually usedto secure a cylinder to a wall or cylinder cart.
When moving or storing acylinder, a threaded protector cap must be fastened to the top of the cylinder.This protects the valve system should it be bumped or dropped. Cylindersshould not be stored or used in a horizontal position. This is because somecylinders contain a liquid which would leak out or be forced out if thecylinder was laid in a flat position. Also, welding guns and other cablesshould not be hung on or near cylinders.
A gun could cause an arc against thecylinder wall or valve assembly, possibly resulting in a weakened cylinder oreven a rupture.Q: How can I tell if my regulator is faulty?A: The following symptoms indicate a faulty regulator:Leaks - if gas leaks externally.Excessive сreep - if delivery pressure continues to rise with the downstreamvalve closed.Faulty gauge - if gauge pointer does not move off the stop pin whenpressurized, nor returns to the stop pin after pressure release.
Do not attemptto repair a faulty regulator. It should be sent to your designated repair center,where special techniques and tools are used by trained personnel.Q: What are some tips for a safe welding environment?A: The area surrounding the welder will be subjected to light, heat, smoke,sparks and fumes. Permanent booths or portable partitions can be used tocontain light rays in one area. The heat and sparks given off are capable of102setting flammable materials on fire.
Therefore, welding should not be done inareas containing flammable gases, vapors, liquids or dusty locations whereexplosions are a possibility. Metals with plating, coatings or paint that comenear the region of the arc may give off smoke and fumes during welding.These fumes may pose a health hazard to the lungs, therefore an exhausthood or booth should be used to remove fumes from the area. When weldingin confined spaces, such as inside tanks, large containers or evencompartments of a ship, toxic fumes may gather.
Also, in an enclosed room,breathable oxygen can be replaced by shielding gases used for welding orpurging. Care must be taken to ensure enough clean air for breathing. Inmany companies, it is routine to provide welders with air masks or selfcontained breathing equipment.Q: How should an operator dress for optimum safety?A: Gloves and clothing should be flame-resistant. Clothing made from adark-colored, tightly woven material is best suited for welding. Gauntlet-typeleather gloves should be worn to protect the hands and wrists. Shirt collarsand shirt cuffs should be buttoned, and open front pockets are not advisableas they may catch sparks.
Also, operators should never store matches orlighters in their pockets. Pants cuffs are not recommended, as they will alsocatch sparks. Tennis shoes do not qualify as adequate foot protection. Hightop leather shoes or boots are absolutely necessary.Vocabularybare spotоголенный участокwire feederмеханизм подачи (электродной или присадочной)проволокиground1) заземление, замыкание на землю 2) соединение наconnectionкорпусpowerswitchпереключатель мощностиrupture1) пробой (изоляции); 2) излом, разрушение, разрывconfinedзамкнутый объём, замкнутое пространствоspaceexhaustвытяжной шкаф; вытяжной колпакhood7Find the English equivalents in the text for the following wordcombinations:путь наименьшего сопротивления, поражение электрическим током,соображения безопасности, защитный колпак, обученный персонал,наносить вред, грубое обращение.103Speaking8Answer each of the questions in text 6 in just one sentence.Model: Q: What can I do to avoid electrical shocks?A: To avoid electrical shocks you should not operate in wet workingconditions check your circuit for poor connections and bare spots.Reading and speaking9Below is a general engine drive routine daily maintenance schedule.Read the information in the chart and say what a welder should do in termsof maintenanceØ once a working day;Ø once a week;Ø once a month.Chart 3Maintenance Schedule Chart8 Hours50 Hours100Hours200Hours250Hours500Hours1000Hours10Wipe up oil and fuel spills immediatelyCheck fluid levels (oil & fuel)Service the air filter (refer to engine manual for specifics)Service air filter element (refer to engine manual for specifics)Clean and tighten weld terminalsChange oilChange oil filter (refer to engine manual for specifics)Clean and tighten battery connectionsClean cooling system (refer to engine manual for specifics)Replace unreadable labels (order from parts list)Replace fuel filterCheck valve clearance (refer to engine manual for specifics)Check and clean spark arrestorTape or replace cracked cablesClean/Set injectors (refer to engine manual for specifics)Blow out or vacuum inside equipment.
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