Hazardous Area Information

8/10/2019 Hazardous Area Information

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Hazardous Area Information

Hazardous Areas are locations where the potential for fire or explosion exists because of gases,

dust, or easily ignitable fibers or flyings in the atmosphere. In North America, hazardous areas are

separated by classes, divisions, and groups to define the level of safety required for equipment

installed in these locations. Classes define the general form of the flammable materials in the

atmosphere. Divisions define the probability of the presence of flammable materials. Groups classify

the exact flammable nature of the material.

In Europe and countries outside of North America, classification of hazardous areas is accomplished

differently. Zones are used to define the probability of the presence of flammable materials.

Protection Types denote the level of safety for the device. Groups classify the exact flammable

nature of the material. These groups are separated differently than North American Groups.

Temperature Identifications convey the maximum surface temperature of the apparatus based on104 F (40 C) ambient. These temperature codes are selected carefully not to exceed the ignition

temperature of the specific gas or vapor to be encountered in the application.

Some classifications are not shown here. For further detailed information, see specific standards

published by approval organizations.

Classifications Inside North America

Classes

Classes are used to define the explosive or ignitable substances that are present in the atmosphere.

Class IFlammable gases or liquid vapors

Class IIIgnitable metal, carbon or organic dusts

Class IIIIgnitable fibrous materials

DivisionsDivisions are used to define the degree of hazard by determining the explosive or ignitable

substance's expected concentration in the atmosphere.

Division 1Contains substances under normal conditions


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Division 2Contains substances under abnormal conditions

Groups

Groups are used to define substances by rating their explosive or ignitable nature, in relation to other

known substances.

Class I Substances

Group AAcetylene

Group BHydrogen or > 30% Hydrogen by Volume

Group CEthyl Ether & Ethylene

Group DAcetone, Ammonia, Benzene & Gasoline

Class II Substances

Group EAluminum, Magnesium & AlloysGroup FCarbon, Coke & Coal

Group GFlour, Grain, Wood, Plastic & Chemicals

Classification Outside North AmericaATEX

Zones

Zones are used to define the degree of hazard by determining the explosive or ignitable substance's

expected concentration in the atmosphere.

Zone 0Contains substances under normal conditions (Continuously)

Zone 1Contains substances under normal conditions (Intermittently)

Zone 2Contains substances under abnormal conditions

Protection Types

dFlameproof (Explosion proof) Enclosure

eIncreased Safety

iaIntrinsic SafetyibIntrinsic Safety

oOil Immersion

pPressurized Apparatus (Purged Apparatus)

qPowder Filling (Sand Filling)

mEncapsulation

nNormally Nonsparking and/or Nonincendive Circuits


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Temperature Codes

F C

T1842 450

T2572 300

T3392 200

T4275 135

T5212 100

T6185 85

Groups

Group IFor application in below ground installations (mines) where methane (firedamp) and coal

dust may be present.

Group IIAFor application in above ground installation where hazards due to propane may exist.

This group most closely matches the North American Group D.Group IIBFor application in above ground installations where hazards due to ethylene may exist.

This group most closely matches the North American Group C.

Group IICFor application in above ground installations where hazards due to hydrogen or

acetylene may exist. This group most closely matche


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Explosion Proof and Intrinsic Safety 101Portions of the standard Spill Buster system operate in various classifiedflammable or

explosive vapor zones or areas as defined in the US under the NEC codes. The location of theequipment on the site must be designed properly; or the equipment must be enclosed inappropriate enclosures, to prevent ignition of these vapors should the failure of a component

occur. Since this is such an important topic we will present a few basics in this manual to help

you or your customers understand the meaning of the various terms defining safe use whenplanning or installing our equipment. Please note that what we have written here is not meant to

supersede anything that may be written in detail in the NEC codes or applicable local codes. I t is

your responsibi li tyand the responsibility of the Authority Having Jurisdictionto study and

follow these codes.The Magnum Spill Buster system may need to be partially or completely located in areas that are

classified as Class1, Division 1, Hazardous Atmospheresas defined in the NEC code section

500. A Class 1, Division 1, safety rating is the highest rating in the US for flammable andcombustible zones. There are several methods to insure that electrical systems are safe to operatein these areas. The Standard Spill Buster system can be modified when required to utilize two of

these basic methods to achieve safe operations in these atmospheres per NEC 2011 electrical

codes: the Intrinsically Safe method, and the Explosion Proof Enclosure method.The sections below provide a brief explanation of these two methods and the different ways in

which they make an electrical system safe for operation in Class 1 Div. 1 areas.

Intrinsic Safety

Intrinsic safety (IS) is a protection technique for safe operation of electrical equipment inhazardous areas by limiting the energy available for ignition of explosive well gases. The

concept of (IS) circuits was originally driven by some devastating coal mine explosions inEurope due to firedampgases being ignited by electricalshortsin the wiring of earlycommunication devices such as the electric telegraph.

In signal and control circuits that can operate with low currents and voltages, the intrinsic safety

approach simplifies circuits and reduces installation costs over other protection methods. High-power circuits such as electric motors or lighting cannot use intrinsic safety methods for

protection.

One of the most common methods for protection is to limit the current by using multiple seriesresistors (assuming that resistors always fail open); and to limit the voltage with multiple Zener

devices to ground (assuming diodes always fail shorted). Approval standards for intrinsic safety

barriers require that the barrier maintains approved levels of voltage and current to the specified

components. This is accomplished by preventing ignition of the protected device and stoppingsparking of damaged wiring to the protected components.


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An example of an Intrinsically Safe (IS) certified Zener barrier is shown

here. Signals going to an electrical device located in a classified

zone are wired into one end of the modular barrier and then wired out into the classified zone.

These can be purchased off the shelf and are certified Intrinsically Safe by various 3rd bodytesting laboratories.

Explosion Proof Enclosures

Explosion Proof (EXP) enclosures are not intended to seal the electrical equipment they containfrom the entry of explosive atmospheres that may be outside the enclosure. Instead, they prevent

any explosion that might occur within the enclosure from initiating a secondary fire or explosion

in the surrounding area outside of the enclosure. Since they are not tightly sealed, liquids andgases may flow into the enclosure.

EXP enclosures are usually made of heavy cast aluminum or stainless steel and are of sufficient

thermal mass and mechanical strength to safely contain an explosion should ignition of the

flammable material occur within the housing. These enclosures are typically produced with wide,flat, flanges but may not have a gasket between those flanges. Should an explosive mixture

ignite inside the enclosure because of an electrical short or an overheated component, the design

of the flanges cools down any hot gases escaping between them enough to prevent the ignition ofthe external combustive atmosphere.

This is important to understand because it means that by design these enclosures are neither

completely air tight nor waterproof. The EXP enclosure that can be used with the Magnumscontrol box includes a window to allow the operator to see the instrument panel. We strongly

recommend that these enclosures be mounted in an upright position and raised off of the ground

to prevent possible internal flooding. If the housing must be at ground level, and especially if itis laid flat with the control panel window in the horizontal position, a protective cover should be

used to keep rain from leaking inside the enclosure and flooding the control box electronics.

Another example of the Explosion Proof methodology would be the manner in which electrical

wire is fed through piping. Per the NEC electrical code spelled out in section 500, cabling fed

through piping usually utilizes tapered pipe threads. The code requires a minimum engagementof six threads; and since it is tapered, the spaces between the threads get tighter as the pipe is

tightened up. There still is the potential for vapors to leak through these threads, but once again

any hot gases escaping through the threads are cooled enough to prevent a secondary explosion.A third example of EXP methodology would be the use of a multi-conductor cable feed through.

The feed through fittings are once again designed to be strong enough to contain an explosion.

These fittings leave sufficient room to provide for stripping the outermost wire jacket andenough room for separating the individual wires from each other. A powdered mixture is then
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mixed together with water and poured in through an access plug to completely surround each

conductor. A common material used is a compound from Cooper Crouse-Hinds called Chico,

which cures to a cement-like consistency. In the event of an internal explosion, any hot,explosive gases escaping through the hardened Chico are cooled before entering the explosive

atmosphere outside.

Here are examples of these two types of enclosures:

Flammability and Combustible Liquids Definitions 101

When using a Spill Buster system it is important to understand the difference between the

definition of flammable liquids and combustible liquids. All flammable and combustible liquids

will vaporize into flammable gases at certain temperatures and pressures. The temperature point

at which a liquid turns to a gas vapor is referred to as the flashpointof the liquid. Thedetermination of the flashpoint for each flammable or combustible liquid is done by performing

what is commonly known as the closedcupflashpoint test.

It should be mentioned that flashpoint was selected as the basis for classification of flammableand combustible liquids because it is directly related to a liquidsability to generate vapor, i.e.,

its volatility. Since it i s the vapor of the li quid, not the li quid itself that burns, vapor generation

becomes the primary factor in determi ning the fir e or explosive hazard.Furthermore, the liquids vapor pressure is an important factor and is a measure of a liquidspropensity to evaporate. The higher the vapor pressure, the more volatile the liquid and, thus, the

more readily the liquid gives off flammable or explosive vapors.

The results of flashpoint testing have been used to help regulating bodies determine thetemperatures at which potentially combustible liquids turn into a vapor, creating a flammable or

explosive gas.

Hazardous locations are further defined by means of the class/division system and have been

formulated by the NEC, CSA, OSHA, and the National Fire Protection Association (NFPA).These definitions are as follows:

Flammable Liquids

Flammable fluids are defined as liquids having closed cup flash points below 100F (37C).

Flammable liquids are referred to as Class I liquids.

? A class IA flammable liquid is a liquid with a flashpoint below 73F (22.8C) and a boiling

point below 100F (37.8C). An example of a class IA liquid is n-pentane, since its flashpoint

and boiling point are 56F (49C) and 97F (36C), respectively.
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?A class IB flammable liquid is a liquid with a flashpoint below 73F (22.8C) and a boiling

point at or above 100F (37.8C). An example of a class IB liquid is acetone, since

its flashpoint and boiling point are 0F (18C) and 133F (56C), respectively.

?A class IC flammable liquid is a liquid with a flashpoint at or above 73F (22.8C) and

below 100F (37.8C). An example of a class IC liquid is turpentine, since its flashpoint

lies in the range from 95 to 102F (35 to 39C).Combustible Liquids

Combustible fluids are defined as liquids having closed cup flash points at or above 100F

(37C). Combustible liquids are referred to as Class II or Class III liquids.

? Class II liquidsflash points at or above 100F (37.8C) and below 140F (60C).

? Class IIIA liquidsflash points at or above 140F (60C) and below 200F (93.4C). c.

? Class IIIB liquidsflash points at or above 200F (93.4C).

An example of a Combustible liquid is the Lamplight Ultra Pure Red Paraffin Lamp Oil thatCET uses for testing new and repaired units before shipment. This material has a flashpoint of

250F (121C) making it a class III liquid. Furthermore, its low toxicity makes it a safe testing

fluid due to its high ignition temperature and the lack of chemicals that are listed in the CERCLA

Hazardous Substance list. CET uses a red colored fluid but it also can be found in clear, orcolored green or blue.


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Hazardous Area Classification andControl of Ignition Sources

This Technical Measures Document refers to the classification of plant into hazardous areas, and thesystematic identification and control of ignition sources

The relevant Level 2 Criteria are5.2.1.3(29)c, 5.2.1.11(63)f, 5.2.1.13and5.2.4.2(93)a.

Design of plant, pipework and general plant layout is considered in Technical Measures Documents

onPlant Layout,Design Codes - Plant,Design Codes - Pipework,Plant Modification / Change

Procedures,Maintenance Procedures.

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) provide for the first

time a specific legal requirement to carry out a hazardous area study, and document the conclusions, in

the form of zones.

General Principles

Hazardous Area Classification for Flammable Gases and Vapours

Area classification may be carried out by direct analogy with typical installations described in established

codes, or by more quantitative methods that require a more detailed knowledge of the plant. The starting

point is to identify sources of release of flammable gas or vapour. These may arise from constant

activities; from time to time in normal operation; or as the result of some unplanned event. In addition,

inside process equipment may be a hazardous area, if both gas/vapour and air are present, though there

is no actual release.

Catastrophic failures, such as vessel or line rupture are not considered by an area classification study. A

hazard identification process such as a Preliminary Hazard Analysis (PHA) or a Hazard and Operability

Study (HAZOP) should consider these abnormal events.

The most commonly used standard in the UK for determining area extent and classification is BS EN

60079 part 101,which has broad applicability. The current version makes clear the direct link between the

amounts of flammable vapour that may be released, the ventilation at that location, and the zone number.

It contains a simplistic calculation relating the size of zone to a rate of release of gas or vapour, but it is

not helpful for liquid releases, where the rate of vaporisation controls the size of the hazardous area.

Other sources of advice, which describe more sophisticated approaches, are the Institute of Petroleum

Model Code of Practice (Area Classification Code for Petroleum Installations, 2002), and the Institution of

Gas Engineers Safety Recommendations SR25, (2001). The IP code is for use by refinery and

petrochemical type operations. The IGE code addresses specifically transmission, distribution and

storage facilities for natural gas, rather than gas utilisation plant, but some of the information will be

relevant to larger scale users.
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Zoning

Hazardous areas are defined in DSEAR as "any place in which an explosive atmosphere may occur in

quantities such as to require special precautions to protect the safety of workers". In this context, 'special

precautions' is best taken as relating to the construction, installation and use of apparatus, as given in BS

EN 60079 -101.

Area classification is a method of analysing and classifying the environment where explosive gas

atmospheres may occur. The main purpose is to facilitate the proper selection and installation of

apparatus to be used safely in that environment, taking into account the properties of the flammable

materials that will be present. DSEAR specifically extends the original scope of this analysis, to take into

account non-electrical sources of ignition, and mobile equipment that creates an ignition risk.

Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence

and duration of an explosive gas atmosphere, as follows:

Zone 0: An area in which an explosive gas atmosphere is present continuously or for long periods;

Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation;

Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs,

will only exist for a short time.

Various sources have tried to place time limits on to these zones, but none have been officially adopted.

The most common values used are:

Zone 0: Explosive atmosphere for more than 1000h/yr

Zone 1: Explosive atmosphere for more than 10, but less than 1000 h/yr

Zone 2: Explosive atmosphere for less than 10h/yr, but still sufficiently likely as to require controls over ignition

sources.

Where people wish to quantify the zone definitions, these values are the most appropriate, but for the

majority of situations a purely qualitative approach is adequate.

When the hazardous areas of a plant have been classified, the remainder will be defined as non-

hazardous, sometimes referred to as 'safe areas'.

The zone definitions take no account of the consequences of a release. If this aspect is important, it may

be addressed by upgrading the specification of equipment or controls over activities allowed within the

zone. The alternative of specifying the extent of zones more conservatively is not generally

recommended, as it leads to more difficulties with equipment selection, and illogicalities in respect of

control over health effects from vapours assumed to be present. Where occupiers choose to define

extensive areas as Zone 1, the practical consequences could usefully be discussed during site

inspection.

As an example:
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A proposal was made to zone an aircraft hanger as Zone 1, although the use of fuels handled above their

flash point would be a rare event. It proved difficult to obtain a floor-cleaning machine certified for Zone 1

areas, though the floor needed sweeping regularly. The option of writing out an exception to normal

instructions to allow a non Ex-protected machine to be used regularly is not recommended. Instead, a

more realistic assessment of the zones is needed, and special instructions issued for the rare event ofusing more volatile fuels.

A hazardous area extent and classification study involves due consideration and documentation of the

following:

The flammable materials that may be present;

The physical properties and characteristics of each of the flammable materials;

The source of potential releases and how they can form explosive atmospheres;

Prevailing operating temperatures and pressures;

Presence, degree and availability of ventilation (forced and natural); Dispersion of released vapours to below flammable limits;

The probability of each release scenario.

These factors enable appropriate selection of zone type and zone extent, and also of equipment. The IP

code gives a methodology for estimating release rates from small diameter holes with pressurised

sources, and shows how both the buoyancy and momentum of the release influence the extent of a zone.

It tabulates values for an LPG mixture, gasoline, natural gas, and refinery hydrogen for pressures up to

100barg. Similarly the IGE code gives a methodology for natural gas, relating the leak rate to the hole-

size and the operating pressure. The tables of dispersion distances to the zone boundary address in the

main quite large diameter deliberate vents. There is in practice little overlap between the codes.

The results of this work should be documented in Hazardous Area Classification data sheets, supported

by appropriate reference drawings showing the extent of the zones around (including above and below

where appropriate) the plant item.

Selection of Equipment

DSEAR sets out the link between zones, and the equipment that may be installed in that zone. This

applies to new or newly modified installations. The equipment categories are defined by the ATEX

equipment directive, set out in UK law as the Equipment and Protective Systems for Use in Potentially

Explosive Atmospheres Regulations 1996. Standards set out different protection concepts, with furthersubdivisions for some types of equipment according to gas group and temperature classification. Most of

the electrical standards have been developed over many years and are now set at international level,

while standards for non-electrical equipment are only just becoming available from CEN.

The DSEAR ACOP describes the provisions concerning existing equipment.


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There are different technical means (protection concepts) of building equipment to the different

categories. These, the standard current in mid 2003, and the letter giving the type of protection are listed

below.

Zone 0 Zone 1 Zone 2

Category 1 Category 2 Category 3

'ia' intrinsically safe

EN 50020, 2002

'd' - Flameproof enclosure

EN 50018 2000

Electrical

Type 'n' - EN 50021 1999

Non electrical

EN 13463-1, 2001

Ex s - Special protection if specifically certified for Zone 0

'p' - Pressurised

EN 50016 2002

'q' - Powder fillingEN 50017, 1998

'o' - Oil immersion

EN 50015, 1998

'e' - Increased safety

EN 50019, 2000

'ib' - Intrinsic safety

EN 50020, 2002

'm' - Encapsulation

EN 50028, 1987

's' - Special protection

Correct selection of electrical equipment for hazardous areas requires the following information:

Classification of the hazardous area (as in zones shown in the table above);

Temperature class or ignition temperature of the gas or vapour involved according to the table below:

Temperature

Classification

Maximum Surface Temperature,

C

Ignition Temperature of gas or vapour,

C

T1 450 >450

T2 300 >300

T3 200 >200

T4 135 >135

T5 100 >100


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T6 85 >85

If several different flammable materials may be present within a particular area, the material that gives the

highest classification dictates the overall area classification. The IP code considers specifically the issue

of hydrogen containing process streams as commonly found on refinery plants. Consideration should be

shown for flammable material that may be generated due to interaction between chemical species.

Ignition Sources - Identification and Control

Ignition sources may be:

Flames;

Direct fired space and process heating;

Use of cigarettes/matches etc;

Cutting and welding flames;

Hot surfaces;

Heated process vessels such as dryers and furnaces;

Hot process vessels;

Space heating equipment;

Mechanical machinery;

Electrical equipment and lights

Spontaneous heating;

Friction heating or sparks;

Impact sparks;

Sparks from electrical equipment;

Stray currents from electrical equipment

Electrostatic discharge sparks:

Lightning strikes.

Electromagnetic radiation of different wavelengths

Vehicles, unless specially designed or modified are likely to contain a range of potential ignition sources

Sources of ignition should be effectively controlled in all hazardous areas by a combination of design

measures, and systems of work:

Using electrical equipment and instrumentation classified for the zone in which it is located. New mechanical

equipment will need to be selected in the same way. (See above);

Earthing of all plant/ equipment (see Technical Measures Document onEarthing)

Elimination of surfaces above auto-ignition temperatures of flammable materials being handled/stored (see

above);

Provision of lightning protection

Correct selection of vehicles/internal combustion engines that have to work in the zoned areas (see Technical

Measures Document onPermit to Work Systems);
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Correct selection of equipment to avoid high intensity electromagnetic radiation sources, e.g. limitations on the

power input to fibre optic systems, avoidance of high intensity lasers or sources of infrared radiation

Prohibition of smoking/use of matches/lighters

Controls over the use of normal vehicles

Controls over activities that create intermittent hazardous areas, e.g. tanker loading/unloading Control of maintenance activities that may cause sparks/hot surfaces/naked flames through a Permit to Work

System

Precautions to control the risk from pyrophoric scale, usually associated with formation of ferrous sulphide inside

process equipment

Direct Fired Heaters, Hot Oil Systems and ProcessesOperating Above Auto-Ignition Temperatures

A range of petrochemical and refinery processes use direct fired heaters, e.g. steam crackers for ethylene

production. Clearly, if the fuel supply to the heater or the pipework carrying the process fluid leaks close

to the furnace, any leak must be expected to find a source of ignition, either directly at the flames, or by a

surface heated by a flame. In these circumstances, hazardous area classification, and appropriate

selection of ATEX equipment is not suitable as a basis of safety for preventing fire and explosion risks.

Instead, safety should be achieved by a combination of a high standard of integrity of fuel and process

pipelines, together with a means of rapid detection and isolation of any pipes that do fail. The

consequences of the failure of a pipe carrying process materials within the furnace should be considered

in any HAZOP study.

Other processes (such as hot oil heating circuits) may handle products above their auto-ignition

temperature. Any such processes should be specifically identified in a safety case. Again, area

classification is not a suitable means of controlling the ignition risks, and the same considerations apply,

as with fired heaters.

Lightning Protection

Protection against lightning involves installation of a surge protection device between each non-earth

bonded core of the cable and the local structure. Further guidance can be found in BS 6651:1999 1-

(Code of practice for protection of structures against lightning). Ignitions caused by lightning cannot be

eliminated entirely, particularly with floating roof tanks, where vapour is usually present around the rim

seal. In these circumstances, measures to mitigate the consequences of a fire should be provided.

Vehicles

Most normal vehicles contain a wide range of ignition sources. These will include electrical circuits; the

inlet and exhaust of any internal combustion engine; electrostatic build up; overheating brakes, and other

moving parts. Site rules should be clear where normal road vehicles may be taken, and areas where they

must be excluded.


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Standard EN 17551sets out the requirements for diesel powdered ATEX category 2 or 3 lift trucks.

Electric powered vehicles can also be built using a combination of this standard and the normal electrical

standards. No specification is available for vehicles with spark ignition engines, and it is unlikely that such

an engine could be built economically. Vehicles certified to ATEX requirements are however expensive,

and for many applications an unprotected type has to be extensively rebuilt. Consequently, manyemployers are likely to try and justify not zoning storage compounds, where lift trucks handle flammable

liquids or gases in containers. In some stores, perhaps with limited use of a vehicle, this may be

acceptable. Discussions have been held with the British Chemical Distributors and Traders Association,

with the objective of clarifying when storage areas should be classified as zone 2. The conclusions from

this exercise will be made available in due course. Discussions are also ongoing, about vehicles with gas

detection systems, designed to shut the engine and isolate other sources of ignition in the event of a gas

release. At present these are sold without any claim for ATEX compliance, but with the suggestion they

may be useful in cases of remote risk.

For the purposes of COMAH, an assessment is needed of the risk that an ignition within a storage

compound will produce a major accident, either directly or because a fire or explosion spreads to involve

other materials. If this is possible, it is more appropriate to provide controls to prevent the spread, rather

than simply apply more conservative zoning, and more restrictive rules on the equipment used in the

store.

Where specialist vehicles (e.g. cranes) are needed during maintenance operations, proper controls and

plant isolation may allow the normal zones to be suspended. Typically these will involve written

instructions, as specified in DSEAR schedule 1, or a formal permit to work system.

Many sites will have operations of filling and emptying road tankers with flammable materials. Controls

will be needed to prevent or minimise the release of gas or vapour but controls over ignition sources are

also needed. Hazardous areas may be considered to exist during the transfer operation, but should not

be present once the transfer is complete. Safe systems of work are needed to ensure safety where such

'transient' zones exist.

Factors for Assessor of a Safety Case to Consider

Is a full set of plans identifying hazardous areas available? For a large site they need not all be provided in the

report, but those examples relevant to the representative set of major accidents upon which the ALARP

demonstration is based must be included.

Have all flammable substances present have been considered during area classification, including raw materials,

intermediates and by products, final product and effluents? Commonly these will be grouped for the purposes of

any area classification study.

Locations where a large release is possible and the extent of hazardous areas has been minimised by the use of

mechanical ventilation should be identified, e.g. gas turbine power generation units, compressor houses. Some

reference to design codes, and commissioning checks to ensure the ventilation achieves the design aim, should be


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provided. The consequences of a loss of power to the system should be included in any section looking at other

consequences of power loss.

Have appropriate standards been used for selection of equipment in hazardous areas? Existing plant will not meet

the formula in DSEAR, but older standards distinguished between electrical equipment suitable for zones 0, 1 and

2. Does the report identify old electrical equipment still in service in a hazardous area, and what assessment hasbeen made to ensure it remains safe for use?

Is there a reference to the impact upon extent and classification of hazardous areas in the section describing plant

modification (see Technical Measures Document onPlant Modification / Change Procedures); passive items like

new walls and buildings can influence this if they obstruct natural ventilation of adjacent plant

Have all ignition sources been considered? A check list is provided in the DSEAR ACOP on control and

mitigation measures, and BS EN 1127 part 11(Explosive atmospheres. Explosion prevention and protection.

Basic concepts and methodology).

Factors that could be considered during an on site

inspection If there are any large areas of zone 1 on the drawings, is there evidence that by design and operation controls, the

sources of release and consequently the location and extent of hazardous areas have been minimised?

Do any zone 2 areas extend to places where the occupier has inadequate control over activities that could create

an ignition source, or is there any suggestion that the zone boundaries have been arbitrarily adjusted to avoid

this?

Has ignition protected electrical equipment been installed and maintained by suitably trained staff.

Are the risks from static discharges controlled properly? Earthing of plant, drums and tankers is the most basic

requirement; other precautions are described in the references

What control measures over ignition sources are adopted in hazardous areas during maintenance; where ignitionsources must be introduced, typical precautions include the use of supplementary ventilation, portable gas

detectors, and inerting of sections of plant. A local project onElectrical Equipment in Flammable

Atmospheres was undertaken and a report of the project's conclusions completed.

Dust Explosions

The COMAH Regulations do not apply to any material if the only risk created is that of a dust explosion.

However, many toxic materials are handled in fine powder form, and a serious dust explosion could

cause a major accident. A dust explosion involving a non-toxic dust like polyethylene would not result in a

major accident as defined in the regulations, unless it also led to loss of containment of a COMAH

substance. A dust explosion could then be an initiator of a major accident. Measures to prevent major

accidents should address all potential initiators.

DSEAR requires that hazardous area classification for flammable dusts should be undertaken in the

same manner as that for flammable gases and vapours. Zoning as described above may be applied,

replacing 'gas atmosphere' with 'dust/air mixtures'. The zone numbers used are 20, 21 and 22,

corresponding to 0,1 and 2 used for gases/vapours
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The only relevant standard to help people zone their plant is BS EN 50281 part 3, 2002 1,which is an

adaptation of the IEC equivalent.

Where toxic dusts are processed, releases into the general atmosphere should be prevented, and the

extent of any zone 21 or 22 outside the containment system should be minimal or non-existent. The

inside of different parts of the plant may need to be zoned as 20, 21 or 22, depending on the conditions atparticular locations.

Classification of dusts relating to autoignition and minimum ignition current is undertaken similarly to

gases/vapours, but involves additional complications.

The explosibility of dusts is dependent upon a number of factors:

chemical composition;

particle size;

oxygen concentration;

Where toxic dusts are handled, in most cases occupiers will need to carry out testing of the product for its

explosion properties. Companies able to undertaken such testing are listed in theIChemE's bookon the

prevention of dust explosions. There is no legally defined test for an explosible dust. However, for many

years we have used a small-scale screening test, the vertical tube test, described in HSG 103 2.The

issues about representative samples of dust, and other factors that might cause the results to vary are

also discussed in this guidance. In general, dusts with a particle size greater than 500 m are unlikely to

cause an explosion. For most chemical products it is preferable to test dust taken from the process, but if

the particle size distribution varies, it is common to test material that passes a 63-micron sieve, and take

this as the worst case.

Ignition due to a hot surface is possible, but the temperature needed to ignite a dust layer depends on

layer thickness and contact time. For COMAH sites with toxic dusts, the most likely hazard would arise in

drying processes, if substantial quantities were held for extended periods hot enough to start self heating

or smouldering combustion.

Status of Guidance

Existing codes of practice provide information with respect to good practice for hazardous area

classification. The standards detailing selection of appropriate electrical apparatus have been updated to

take into consideration ventilation effects.

European equipment standards may become 'harmonised' when a reference to them is published in the

Official Journal of the European Community. A list of ATEX harmonised standards can be checked on

theEU web site :

Equipment built to such a harmonised standard may assume automatic conformity with those essential

safety requirements of relevant directives that are covered by the standard. The EPS regulations describe

the conformity assessment procedures that apply to different types of equipment.
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Reference Documents

HS(G)512Storage of flammable liquids in containers, HSE, 1998.

Appendix 3 describes the requirements for hazardous area classification. The use of BS EN 60079-10: 20031,and

the Institute of Petroleum Code 'Area Classification Code for Petroleum Installations: Model Code of practice in

the Petroleum Industry' Part 15 are recommended. It suggests all drum stores should be zone 2, to a height 1m

above the stack. The same advice appears in HSG 166 and HSG 113 on ignition protected lift trucks. Discussions

with industry on the relaxation of this in particular circumstances are ongoing.

HS(G)712Chemical warehousing: the storage of packaged dangerous substances, HSE, 1998.

This contains very limited information on hazardous area classification or control of ignition sources

HS(G)1032Safe handling of combustible dusts: precautions against explosions, HSE, 2nd Edition, 2003

HS(G)1132Lift trucks in potentially flammable atmospheres. The contents of this have been overtaken to some

degree by DSEAR, and the EPS regulations.

HS(G)1402Safe use and handling of flammable liquids, HSE, 1996.

Appendix 3 describes the requirements for hazardous area classification. The use of BS EN 60079-14 1and the

Institute of Petroleum Code 'Area Classification Code for Petroleum Installations: Model Code of practice in the

Petroleum Industry' Part 15 are recommended. This is aimed mainly at small scale handling, with containers of

200 litres or less.

HS(G)1662Formula for health and safety: guidance for small and medium sized firms in the chemical industry,

HSE, 1997.

The guidance describes the requirements for hazardous area classification, and gives some typical examples.

These should now be seen as rather conservative. The use of BS EN 60079-14, BS EN 50281 and BS EN

605291are recommended. This is basic level guidance, and COMAH reports should normally reference more

specific publications, such as the other HSG series books listed, and other items in this list.

HS(G)1762The storage of flammable liquids in tanks, HSE, 1998.

Paragraphs 35 to 39 describe the requirements for hazardous area classification. This cross references BS EN

60079-10: 20031,and the Institute of Petroleum Code 'Area Classification Code for Petroleum Installations:

Institute of Petroleum Model Code of Safe Practice, part 15, area classification for installations handling

flammable fluids, 2nd edition 2002.

HS(G)1862The bulk transfer of dangerous liquids and gases between ship and shore, HSE, 1999.

Appendix 2 describes the requirements for hazardous area classification. The use of BS EN 60079-10 1and the

Institute of Petroleum Code 'Area Classification Code for Petroleum Installations: Model Code of practice in the

Petroleum Industry' Part 15 are recommended. Contains useful information about electrostatic hazards during

unloading.

LPGA CoP 1 Bulk LPG storage at fixed installations. Part 1: Design, installation and operation of vessels located

above ground, LP Gas Association, 1998.

LPGA codes have not previously drawn a clear distinction between hazardous areas, and separation distances

required for other reasons. These are currently under revision, and will specify hazardous areas, that in most cases

will be smaller than the separation distance. Current codes are listed on theUKLPG website .
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Model Code of practice in the Petroleum Industry' Part 15 is recommended. The guidance also recommends that

zones be recorded in a plan to prevent sources of ignition being brought in.

Electrical Equipment

Standards produced by Europe in the BS EN 50014 range are gradually being superseded by international

standards produced in the range BS IEC 600791.Equipment built to older standards, including purely national

standards may remain in service, provided it is properly maintained. The IEC range of standards also includes

documents on selection, installation and maintenance of equipment for use in explosive atmospheres.

Non-electrical equipment

The first standard for explosion protected non-electrical equipment is BS EN 13463 part 11.It describes

requirements for "Category 3" equipment. Further parts of this standard are well advanced and will appear during

2004.

BS EN 1127-1: 19981Explosive atmospheres - Explosion prevention and protection - Part 1: Basic concepts and

methodology, British Standards Institution.

This gives additional general advice on the many of the issues covered in this TMD.

Electrostatic ignition risks

The most recent general source of advice was drafted by a European standards working group, but was

published in the UK as BS PD R044-001 and not as a full standard. It contains much useful advice about

limiting pumping speeds, electrostatic risks from clothing, and many detailed operations. The two parts of

the older BS 5958: 19911Code of Practice for the control of undesirable static electricity remain current,

because they contain some useful information not duplicated by the PD. The two parts are:

Part 1: 1991 General considerations;

Part 2: 1991 Recommendations for particular industrial situations

BS EN 502811.The different parts of this standard set out requirements for construction of equipment for use in

atmospheres containing explosive dusts; information about selection and maintenance; and

BS EN 50281-3: 20021covers the classification of areas where combustible dusts are or may be present.

BS 6651:19991.Code of practice for protection of structures against lightning, British Standards Institution.

Section 9 provides guidance on lightning protection of structures with inherent explosive risks.

BS 7430:19981Code of practice for earthing, British Standards Institution.

Lightning protection. Section 23 provides guidance on lightning protection.

Further Reading MaterialCox, A.W., Lees, F.P. and Ang, M.L., 'Classification of Hazardous Locations', 1993.

This was a study led by a consortium of the chemical, electrical and mechanical engineering institutes,

and showed how the subject spanned the traditional divides. It was important in the development of

ideas, but provides no new methodology for users.
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A Guide to Safety in Aerosol Manufacture, BAMA, Third Edition, 1999.

Dust Explosion Prevention and Protection: A Practical Guide, IChemE,ISBN 0852954107

A practitioner's handbook -Electrical installation and maintenance in potentially explosive atmospheres ,

Publication No. 186, The Engineering Equipment and Materials Users Association, 1997.

References

Danger of Explosion Due to Explosion Proof Instruments in the Presence ofAcetyleneAuthor Dipl. Ing. Jrg Liebetruth

In the every day life of the fire brigade, the danger of acetylene is equivalent to the danger ofother flammable gases and vapors and can create one of the most explosive situations.
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Acetylene has been the cause of many fires and disastrous accidents in the industry, and firebrigades must be aware of the danger an acetylene leak can cause.

Two kinds of danger can arise from acetylene gas bottles:

First of there is the danger of pressure when overheating occurs due to fire, causing the gas bottle

to explode. The second danger arises from an unsupervised acetylene leak; e.g., gas bottles whichare not air-tight. Under certain circumstances, acetylene can form a dangerously explosive gas-airmixture with the ambient air.

With acetylene there is the danger of ignition followed by an explosion in a wide range of the gas-airratio. In other words, acetylene ignites at almost every gas-air ratio.

The explosive range of any explosive gas or vapor is limited by the lower and upper explosion limits(LEL and UEL), which are measured in a ratio of the % volume of flammable material to the totalvolume of the mixture. Below the LEL, the mixture is too sparse and above the UEL the content istoo concentrated. The explosive range for acetylene is between 2.3 and 78.0% volume, so anyignition source must be avoided.

For the fire brigade, this means that their personal protective clothing and electrical equipment, suchas lights, radio equipment, and gas detectors must be explosion proof. However, explosionapprovals differ as explained below:

Explosion proof electrical instruments are divided into different categories, which are specified in theapproval description. Consequently, it is possible that fire fighters can expose themselves to danger

despite "explosion proof instruments," and that their instruments do not have approval for use inareas where certain flammable gases occur.

In explosive atmospheres only appropriately certified instruments, which are marked as such, maybe used. The details on the explosion proof instruments label must include the manufacturer'sname, the device designation, and the product number. The label must be visible, legible, and long-lasting. As an example, the G750 label is shown below:


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EEx ib d II C T5

EExElectrical equipment for explosion hazardous areas The instrument complies with valid European (EN) standards

(certified by a recognized European testing authority).Ex

The instrument complies with valid German (DIN) standards(certified by a recognized testing authority).

dTypes of ignition protectionFlameproof enclosure

e Increased safety

ia Intrinsic safety: Category ia

ib Category ib

m Molding

p Pressurized apparatus

o Oil immersion

q Powder filling

IExplosion groupsElectrical equipment for mining

II Electrical equipment for all other hazardous areas

II ALimit of slotwidth:

> 0.9mm (flameproof enclosure)

II B 0.5mm to 0.9mm (flameproof enclosure)

II C < 0.5mm (flameproof enclosure)

T1 to T6 Temperature classes

Table 1 Identification of electrical equipment for explosion hazardous areas (EN 50014)

The type of ignition protection describes (according to the manufacturing requirements of the EN50014 standards) the technical details of the ignition protection of explosion proof electricalinstruments. In assessment it plays only a secondary roll, as from a safety point of view allstandardized types of ignition protection are regarded as similar. The application depends inessence on the type and function of the instrument. The type of ignition protection for gas warningdevices is in most cases "intrinsic safety" or "flameproof enclosure."

Fire brigade members should pay special attention to EXPLOSION GROUPS and TEMPERATURECLASSES:

Flammable gases have specific material characteristics that must be considered when assessingignition danger. Some gases are easy to ignite, while others are difficult. Instruments that are usedin these atmospheres must take these characteristics into account and must be manufacturedaccordingly.

The easiest method would be to manufacture all explosion proof electrical instruments inaccordance with the maximum requirements, independent from their respective applications. Sincethis is economically impossible, all explosion proof material is categorized by the qualities of thespecific components of the explosive atmosphere for which it is intended.


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The explosion groups classify the ability of an explosive gas-air mixture to ignite, whereas thetemperature classes subdivide the gas-air mixtures according to their ignition temperature.

The danger of the gas increases from explosion groups IIA to IIC and also from temperature classT1 to T6. Therefore, the requirements for electrical instruments increase within these explosion

groups and temperature classes. Instruments that are used by fire brigades are all group IIinstruments.

Explosion

groups

Temperature Classes (maximum temperature)

T1

(450C)T2

(300C)T3

(200C)T4 (135C) T5

(100C)T6

(85C)

IIA Ammonia630C

Carbonmonxide605C

Methane595C

Benzene555C

Acetone540C

Toluene535C

Ethane515C

Propane

470C

Ethylacetate460C

Methanol455C

Ethyl acohol425C

Trichlorethylene410C

n-Propylalcohol375C

n-Butane365C

n-Butyl alcohol340C

Benzine220C - 330C

Diesel fuel220C - 330C

Heating oils220C - 330C

n-Hexane240C

Acetaldehyde140C

IIB Town gas560C

Ethylene oxide440C

Ethylene425

Hydrogensulphide270C

Ethyl glycol235C

Ethyl ether180C

IIC Hydrogen560C

Acetylene305C

Carbondisulphide

95C

For the incalculable work of fire brigade forces, explosion proof material must be categorizedaccording to maximum requirements. Where a fireman has to deal with any kind of dangerous gas,his instruments should have the marking IIC (explosion group), since these instruments areclassified for use with all lower explosion groups, as well.


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The maximum demand, namely temperature group T6, is excessive because technically it requires alot of research and development time, energy, and money. The only gas which falls in group T6(carbon disulphide) is found very rarely, and moreover the toxic effect of this gas is more dangerousthan the explosion danger. Therefore, T6 is rarely found in portable instruments. Groups IIC T4 orT5 are sufficient, as they cover more then 99.9% of all gases.

Sometimes instruments are approved for a specific explosion group, but individual gases from ahigher explosion group are also tested (e.g. instruments with the marking EEx ib d IIB+H2 T4).These instruments can be used in atmospheres which contain IIB gases and hydrogen, but in anatmosphere which contains acetylene there is the danger of ignition and therefore they are notrecommended for fire brigade use.

Multicomponent Gas DetectorsThe G750 gas measuring and warning unit from GfG Instrumentation can simultaneously measureand monitor up to six different gases. With interchangeable, plug-in "smart sensors," the user is ableto adjust the compact, hand-held instrument to comply with new or changing requirements. Everysensor has a memory chip with pre-set data that is automatically transferred to the instrument onceit is plugged in.

The G750 meets the highest demands of measuring technique suitability and approval for operationin explosive atmospheres. The suitability of its measuring technique is certified by the PFG functiontest. The G750 can be used for IIC, the most dangerous explosion group. In addition, it is the onlymulti-gas detector that is equipped with an IR-CO2 sensor, and which is allowed to be used in adangerously explosive acetylene atmosphere. All measured gas concentrations are simultaneouslydisplayed on a rich in contrast graphic display, which offers additional display illumination and azoom function for single gas concentration readouts. In normal operation, the instrument can beoperated with only two buttons ("ON" and "OFF"). In addition, there are also special buttons for theavailable user functions.

In service mode the instrument can be configured with a menu, and the most important parametersare protected by safety codes. With a rechargeable battery the G750 can operate for more than 8hours on one charge in diffusion mode.

For every measured gas, three alarm thresholds are possible. Different alarm frequencies indicatewhich threshold has activated the alarm, and the display shows which alarm was caused by whichgas. Monitoring is performed continuously through diffusion or with the help of a built-in pump. Ifneeded, the G750 can also perform a dosimeter function to control short and long term exposurelevels.

The alarm signals must be clearly recognizable in every situation. Therefore, the instrumentprovides 4 different warning systems:1. A penetrating audible signal with a sound level of 80 dB. 2. An earphone alarm for very loud environments. 3. A flashing alarm light with 6 LEDs.4. A built-in vibrating alarm (optional).

An optional built-in data logger can save peak, average, and current values together with the date,time, and location when the measurements of dangerous goods are required to be documented,according to regulations. The data can be transmitted to a computer by means of professionallydeveloped DOS or Windows programs.


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gWith the attitude of lets not blow it good planets are hard to find, the Linc Energy Blog is writing about

energy. Well explore alternative energy and conventional energy. Were interesting in providing an outlet

to voice thoughts on bridging fossil fuels like natural gas to alternative energy.

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Difference between intrinsically safe and explosion

proof

bySusan Bender|on Thursday, 27 December 2012 |inProcess and Industrial Products|0 Comments

Many of our products are electrical equipment and used in hazardous areas, so were often asked

What is the difference between explosion proof and intrinsically safe?

At times electrical equipment must be used or installed in locations where vapors or gases are present.

These areas are commonly referred to as hazardous locations. When equipment needs to be installed

in these areas strict material and design guidelines must be followed. The NEC or National Electrical

Codeis a document providing guidelines for electricians, electrical contractors, inspectors and engineers

In the United States. These guidelines are part of the National Fire Code Series and published by the

National Fire Protection Association, with updates every three years.

The NEC defines protection techniques equipment manufacturers must use when designing equipmentintended for use in hazardous areas. NEC definitions set the parameters manufacturers must comply with

for any component that is to be installed in a hazardous area. These definitions are: Explosion proof, dust

ignition proof, dust tight, purged/pressurized, intrinsically safe, and hermetically sealed.

The majority of the equipment we represent that is used in hazardous locations is either explosion

prooforintrinsically safe.

Explosion proof
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Equipment with an explosion proofclassification

doesnt mean the equipment will survive an

explosion. Instead it means that the equipment is

housed or has an enclosure which prevents an

internal spark from causing a much larger explosion.

In this case, the enclosure must be engineered tocontain any flash or explosion. The housing on this

type of equipment is generally constructed of

stainless steel or cast aluminum and strong enough

to contain an explosion should gas or vapors seep

into the enclosure and the internal electronics ignite.

The equipment must be designed so that if there is

an internal explosion, the external surface

temperature does not meet or exceed the ignition

temperature of the gases in the group the equipment

has been rated for.

Intrinsically Safe

An Intrinsically safe rating means that the electronics or wiring contained within the equipment cannot

spark or cannot accumulate enough energy to ignite the gas or vapor at the location. Additionally the

surface temperature of the equipment cannot get high enough to ignite the gas or vapor at the location.

Classifications of Hazardous Atmospheres

The NEC also is a classification tool for hazardous conditions. Many of the products we sell are typically

associated with a hazardous location classification. For example, some of Western Technology Lights are

Class I Division 1 and 2, and Class II Division 1 and 2. The following explains what the classification

denotes.

There are three typesof hazardous conditions or classes:

Class I - gases and vapor Class IIcombustible dust Class III - fibers and flyings

There are two kinds of hazardous conditions within a class.

With Class I pertaining to gases and vapor hazards, the two kindsare:

Division 1:The gases or vapors are alwayspresent at sufficient concentrations to be anexplosion hazard.

Division 2: The gases or vapors may be present, and if they are they are likely to be in sufficientconcentrations to be an explosion hazard.

8100 Solid State LED Explosion Proof Kick-It

Tough Work Light

Class I Div 1 and Div 2 Groups C & D / Class II Div

1 and Div 2 Groups E, F & G


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In Class I there are four Groups (A, B, C, D): which are classifications of atmospheres by the degree of

volatility with A being the most hazardous and D being the least volatile group.

Group A: Acetylene Group B: Hydrogen and manufactured gases containing Hydrogen Group C: Petrochemicals Group D: Petrochemicals (includes methane)

For information on Class II and Class III download Hazardous location and OSHA Regulation information.

What is the difference between explosion proof and intrinsically safe? In explosion-proof equipment the

internals must be engineered to contain an internal explosion, and avert a much larger detonation.

Intrinsically safe rating means the electronics cannot sparkor create sufficient energy to ignite. In both

cases the equipments surface temperature cannot meet or ignite the gas or vapor ignition temperatures

of the group it is rated in.

Common Class locations:

Class I Locations Class II Locations Class III Locations

Petroleum refineries, and

gasoline storage and dispensing

areas Dry cleaning facilities where

vapors from cleaning fluids are

present Spray finishing areas

Aircraft hangars and fuel

servicing areas Utility gas plants and

operations involving the storage

and handling of liquifiedpetroleum gas or natural gas

Grain elevators

Flour and feed mills

Plants that manufacture, useor store magnesium or

aluminum powders

Plastic, medicine andfirework manufacturers

Starch or candy producers

Spice-grinding plants, sugarplants and cocoa plants; and

Coal preparation plants and

other carbon handling orprocessing areas

Textile mills, cotton gins;

Cotton seed mills, flax

processing plants; and Plants that shape, pulverize

or cut wood and create sawdust

or flyings.


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2. Five years warranty

3. Pass UL,TUV(GS,CE),SAA certification

Its the first Anti-explosion LED high bay light in domestic,with Ex-marking ExnR II T4GC, which access to the

national explosion-proof certification by the authority.

Explosion-proof certificate

Products Warranty Service regulation

Application

1. Gas station,processing workshop or storage warehouse for Edible Oil,food and other oil products,smelting

workshop which easily producing explosive dust and gases; chemical factories,warehouses and other special places.

2. Also can applied in Factories,workshops,Cargo space,exhibition centers,shopping malls or

supermarkets,stadiums,toll stations, etc.

150W explosion-proof LED High Bay Light Applied in Thailand
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1Product Appearance


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Specialty

1,Using high power COB Leds and Meanwell driver; the lamps luminous efficiency can reach 80 -100LM/W, and Ra

>80;Fins heating dissipation design enables the LED Tj within 85, lifespan more than 35,000 hours ,the max power

up to 200W; with protecting rate: IP65.

2, The anti-explosion high bay light is designed and certified according to standards for safety as below: GB3836.1-

2010 Explosive environment Part 1:Equipment General Requirements;GB3836.8-2003 Electrical apparatus for

explosive gas atmospheres-Part8: standards for n type electrical equipment; with Ex-marking ExnRT4Gc.

3, The light can be used at a place in which an explosive atmosphere in the form of explosive dust or combustible

fibre in mixture with air is likely to occur continuously or frequently in short time, or for long periods in normal

operation. According to the classification of explosion proof grade and application, the light can be use in Zone2.

Surface temperature of item for safety:135,Such as chemical factory or warehouse, gas station except mines.

2Shape Structure

Shell MaterialAluminum Alloy

Shell Colorhoar/ Black

Weight13.5Kg

3Explosion-proof Parameters

1Explosion-proofGrade

ExnRT4Gc

ExExplosion-proof

1nR-Explosion proof form code of explosion proof electric equipment, nR for restrict breathing type, the others: D

for explosion suppression type; IA for flameproof intrinsically safe type; MB for pouring type .;


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2-Explosion proof electrical equipment is divided into type ,,class; class I used for coal mine gas

environment; class II, III used for other explosive gases electric equipments except coal mines which can easily

generate gas.

3T4-equipment external surface temperature range ( T4 means the temperature of any point on the external

surface of UFO explosion-proof mining lamp 135 );

4Gc-Electric equipment protection level, and has a corresponding relationship to its used place, Gc level of

protection for the general, and it can be used in explosive gas environmentZone 2;

(2)Hazardous area classification

Explosive substance Area definitionChinesestandard

Foreignstandards

GasClass

Under normal circumstances, the explosive gas mixturecontinuously or long time existence.

Zone 0

Div.1Under normal circumstances, the explosive gas mixture islikely to existent site

Zone 1

Under normal circumstances, the explosive gas mixture isnot possible appear, Only in abnormal circumstances,

occasionally or short time existed site ;

Zone 2 Div.2

Dust or fiber

Class/Class

Under normal circumstances, explosive dust or combustiblefibre and air mixture may be continuous, a short timefrequent appear or long time existence.

Zone 10 Div.1

Under normal circumstances, explosive dust or combustiblefibre and air mixture can not appear, just in case ofabnormal condition, occasionally or short time appears.

Zone 11 Div.2

(3)Gas temperature group

Temperaturecategory

Explosion proofelectrical equipmentsurface temperature

Common explosive gas

T1 450

MethaneTolueneMethyl esterEthanePropaneAcetoneAcrylic

acid

Benzene

Styrene

Carbon monoxide

Ethyl acetate

Acetic acid

ChlorobenzeneMethyl acetateAmmoniaAcrylic esterTwo etherCity

gasHydrogenWater gas

T2 300

MethanolEthanolEthyl benzenePropyl alcoholPropyleneButyl

alcoholButaneButyl acetateAmyl acetateCyclopentaneButadiene

Epoxy propaneEthyleneAcetylene

T3 200

PentaneAmyl alcoholHexaneHexyl alcoholHeptaneOctaneRing

of ethanolTurpentine oilNaphthaPetroleum (gasoline )Fuel oil

Amyl alcoholfourTwo etherAcroleinHydrocarbon

T4 135AcetaldehydeTetrafluoroethyleneTrimethylamineEthyl etherTwo

ether

T5 100 Carbon disulfide

T6 85 Acid ethyl esterNitrous acid ethyl ester

This series explosion-proof lamp temperature group is T4, according to the above standard data, this series lamp can

be used in the warehouse, workshop in the scope of T1, T2, T3, T4, and related places that require explosion-proof

lamp lighting can be applied.

4

Parameter

Input Voltage AC100240V Color Rendering Index Ra80

FreqencyRange 5060Hz Beam Angle 100


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Power Factor >0.97 LED Reduction Rate 13% / 1,000Hrs

Power Efficiency >92% Color Temperature 27007000K

LED Working Voltage DC3036V Working Temperature -20+45

LED Power 200W IP Grade IP65

Total Power 217W Working Life-span >35000HLuminous Efficiency 80100lm / W Power line VDE 31.5mm2

Connect wire BrownL BlueN Yellow or GreenG

7Illumination Distance/illuminance/Irradiated Area

You are here: Leoyo Holdings Group Co.,Ltd. Products

dJ82 Flame-proof explosion- proof Energy-saving lamp (II C)


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Application

1Can be used in hazardous environments of petroleum exploitation, smelting, chemical

industry, military industry etc. enterprise;2Can be used in Zone 1 and Zone 2 explosive atmosphere;

3Can be used in explosive atmosphere of temperature between T1 and T5 of class IIA , IIB

and IIC.

4Can be used in locations which contain corrosive gas;

5Can be used as lighting of workshop, warehouse, factory building and outdoors .

Type implication

Features

1The shell is formed by die-cast Aluminum Alloy of


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high quality, treated with high voltage electrostatic plastic-

spraying and advanced baking process after shot-blasting

cleaning, with strong corrosion-proof capacity.

2The shell uses optimal design and high-precision die-

casting so that it has compact structure, aesthetic

appearance, dense material and higher mechanical strength.3Both of flame-proof compartments of explosion-proof

lamp are completely independent and adopt screw thread

flame-proof and silastic obturating ring to prevent waterentering, of which purpose-made obturating ring and

unique structure has strong water-proof and dust-proof

function without affecting explosive gas lit object that may

be produced to spill from flame-proof threads joint face.

4Convenient to install and maintain. Install lamp cap and

connect power cord at first when installing, then screw

main lamp body onto lamp cover ( note: align arrow tip,

combine cover and body closely) and fasten? side? retainerbolt ; demount the main lamp body when maintaining so

that it will be very convenient to examine and repair for

circuitry and bulb etc.

5Toughened steel glass shade can withstand high energy

(4J) impact and thermal shot test without damage.

6The steel pipe or the electric cable wiring.

Main standards

GB3836.1-2000. GB3836.2-2000 which are equivalent to IEC60079-0. IEC60079-1. EN50014.EN50018

Outline and installation dimension


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Outline and typical installation example


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Explosion Proof Comparison for Digital Vortex Flowmeter

Explosion proof rated equipment is constructed so that it cannot set off an explosion whensurrounded by specified flammable gases or dust. These specifications are complex and everycountry insists on making their own rating system.
http://digitalvortexflowmeter.com/wp-content/uploads/2012/11/ExplosionProofComparison.jpg


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InExplosion Proof Equipmentthe manufacturer is ensuring that the equipment you purchase issuitable for the environment you wish to use it in.

Devices that areIntrinsically Safeare also required to carry an intrinsically safe label for use in the

desired environment.For example a householdrefineryis designed either to contain any explosion within the device, or isdesigned not to produce sparks with sufficient energy to trigger an explosion. Selecting an explosion

proof digital vortex meter is a way engineers ensure the ultimate safety of the use of flow measuringdevices in their factories and plants.

Many strategies exist for safety in electrical installations. The simplest strategy is to minimize theamount of electrical equipment installed in a hazardous area, either by keeping the equipment out of

the area altogether or by making the area less hazardous by process improvements or ventilation withclean air.non-incendiveequipment and wiring methods are practices where apparatus is designedwith low power levels and low stored energy, so that an arc produced during normal functioning of

the equipment or as the result of equipment failure has insufficient energy to initiate ignition of theexplosive mixture. Equipment enclosures can be pressurized with clean air or inert gas and designedwith various controls to remove power or provide notification in case of supply or pressure loss ofsuch gases. Arc-producing elements of the equipment can also be isolated from the surrounding

atmosphere by encapsulation, immersion in oil, sand, etc. Heat producing elements such as motorwinding, electrical heaters, including heat tracing and lighting fixtures are often designed to limittheir maximum temperature below the autoignition temperature of the material involved. Bothexternal and internal temperatures are taken into consideration.

As in most fields of electrical installation, different countries have approached the standardizationand testing of equipment for hazardous areas in different ways. As world trade becomes more

important in distribution of electrical products, international standards are slowly converging so thata wider range of acceptable techniques can be approved by national regulatory agencies.

Area classification is required by governmental bodies, for example the U.S.Occupational Safety

and Health Administrationand compliance is enforced.

Documentation requirements are varied. Often an area classification plan-view is provided to identifyequipment ratings and installation techniques to be used for each classified plant area. The plan maycontain the list of chemicals with their group and temperature rating, and elevation details shaded toindicate Class, Division(Zone) and group combination. The area classification process would require

the participation of operations, maintenance, safety, electrical and instrumentation professionals, theuse of process diagrams and material flows,MSDSand any pertinent

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