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Flameproof Hoists It requires a special knowhow for trasporting, shifting or lifting the material in:
- Chemical Plants
- Coal Mines
- Fertilizer Companies
- Heavy Wter Projects
- Mineral Oil Industries
- Petrochemical Plants
- Pharmaceutical Industries
- Plastic Industires
Whereever inflammable, explosive and corrosive vapours, liquids and gases are expected to be present, the most important demand to be met by material handling equipments in such hazardous areas is high degree of reliability and perfection, SINCE FAULLTS MAY ENTAIL SERIOUS DANGER TO PERSONNEL & PLANT.
CAUSES OF EXPLOSION:
There are many causes of explosion.
Anyone or more than one of them may cause explosion, such as:
- Electrostatic charge. Electrical spark
- Spark of mechanical origin
- Slow discharge
- Arc discharge
The easiest way to avoid explosion is to avoid the ceration of and explosive atmosphere by providing adequate vetilation or confining work process to closed systems which prevent the occurence of dangerous gases.
For selection of explosion proof material handling equipment, following points should be taken care of:
1.Hazardous Areas : Hazardous areas are catagoristed into zones depending on the frequency and duration as per Is-5572(Part-1) i.e Zone ')', Zone 1 and Zone 2.
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Classification of Area as per IS-5572(Part-1)1994
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Zone 0
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Hazardous atmosphere is continiously present
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Zone 1
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Hazardous atmosphere is likely to be present at any time under normal operating conditions
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Zone 2
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Hazardous atmosphere is likely to be present only under abnormal conditions and for a short period.
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2.Ignition Temperature : Flammable gases and vapours are categorised in temperature classes form T1 to T6. Ignition temperature is the lowest temperature at which the flammable gas will ignite.
The ignition temperature classes are shown in the table here below.
3.Hazardous Gas : Hazardous gases have been classified in IS:2148-1981 and are associated only with flameproof enclosures. These gases along with the ignition temperature classes are listed in following table.
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Gas Group
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Temperatures class with Ignition temperature in C
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T1
Above 450
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T2
300-450
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T3
200-300
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T4
135-200
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T5
100-135
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T6
85-100
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I
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Methane
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IIA
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Carnpm Monoxide, Ind. Methane, Ammonia, Propane, Benzene, Acetone, Ethylacetate, Methanol
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Butane, Cyclohexane, Amy-Laccetate, Ethonal,
N-Butanol
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Benzene
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Ethyl Ether
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IIB
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Coke oven gas
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Ethylene, Ethylene Oxide, 1-3 Butadience
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Diethyl Ether
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IIC
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Hydrogen
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SAFEX flame proof hoists are designed in modular construction which greatly simplifies repairs and cuts down time. Safex flame proof hoists are designed in accordance with IS-3938. all electrical apparatus are housed in flame proof enclosures confirming to SI-2148 and mechnical components are designed so that there is no ferrous metal to ferrous metal contact in order to void any chance of sparking. hence SAFEX flame hoists are flame proof as well as spark proof.
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