5. Sources of Ignition
• A source of energy is all that is needed to touch off an explosion when
flammable gases or combustible dusts are mixed in the proper
proportion with air.
• Equipment :
switches
circuit breakers
motor starters
push button stations
plug/receptacles
Can produce arcs or sparks
in normal operation when
contacts are open & close
6. What are Hazardous Locations
• The identification of a danger zone in a chemical or
petrochemical plant should be carried out by highly qualified
personnel. Normally process managers, who establish where
in the plant there is a presence of either a continuous or
occasional explosive atmosphere.
• The most frequent danger points are found where there is a
possibility of inflammable gas leaks, that can occur during
normal operation or due to a breakdown.
• The classification is determined by the quantity of gas present
in given zone.
7. Example of the Chemical Plant Layout
Plant Requirement
Gas or Vapours
Zone 1
(Division 1)
Class I
Gas Groups IIC
Temperature T5 100oc
Hydrogen Acetylene
Area in which a
mixture of explosive
gas may be present
during the normal
operation of the
plant
Equipment Suitable (eg. Lighting Fitting)
Class 1 Zone 1 EEx “d” IIC T5 IP66
(Division 1)
OR
Class 1 Zone 1 EEx “e” IIC T5 IP66
(Division 1)
8. Example of the Chemical Plant Layout
Plant Requirement
Powders/Explosive Dust
Zone 2
(Division 2)
Class II
Gas Groups IIC
Temperature T4 135oc
Hydrogen Acetylene
An Area in which the
mixture of explosive
gas is not normally
present, but is only
present for brief
periods of time
Equipment Suitable (eg. Lighting Fitting)
Class II Zone 2 EEx “n” IIC T4 IP66
(Division 2)
OR
Zone 1 Area Fitting
9. Work places with danger of explosion or fire for which and
anti-explosive electric equipment is necessary
Industries, Depot, Etc. (Potentially Explosive gases or materials)
• Acetylene
• Adhesive Tapes
• Adhesive
• Artificial Fruit Ripening
• Asphalt Rock Distillation
• Bone Degreasing
• Bushing Metal Powders
• Calcium Caribe
• Carbon Black Production
• Carbon Sulphide
• Celluloid
• Cereal Processing
• Coal
•Coke Plants
• Compression Units
• Cosmetics
• Cotton Mills
• Cdextrin Production
• Distilleries
• Dry Cleaning
• Dye & Paint Factories
• Electrode Construction
• Explosives
• Extraction of Olive
Residue Oil
• Taf Hidrogenation
• Film Development Labs
• Film Production
• Foundries
• Gas Cylinder Depost
• Gasworks
• Glues
• Insecticides
• Knock Suppressors
• Liquefied Petroleum Gas
• Liquor Mills
• Magnesium
• Matches
• Metal Degreasing
• Metallurgic Industries
• Mineral Oil Refinery
• Oil Industries
• Organic Dyes
• Organic Reagents
• Organic Synthesis
Compounds
• Perfume Production
• Perfume Essence Depots
• Pharmaceutical Products
• Polyvinyl Resins
• Powder Spray
• Printing Ink
• Pyroporic Rocks
• Pyrotechnics Mistures
• Rayon
• Reagents
• Rice Mills
• Rubber
• Shoe Polishes
• Sugar Refinery
• Sulphur Flour
• Synthetic Ammonia
• Synthetic Methil Alcohol
• Synthetic Resin Processing
• Synthetic Resin
Production
• Tar Distillation
• Tar Processing
• Turpentine
• Wood Flour
• Wood Storage
11. Basic Principles
• To define the various hazard zones in the interior of a plant
(Class/Zone/Group?)
• Flash point and self-inflammation temperature in ºc for
gases, self flammation temperature in layers or in clouds
for dust
• To select the choice of electrical equipments that can be
installed in that zone to ward off the danger of explosions
caused by accidental sparks or surface overheating
12. Explosion-proof Standard – “Method of
Protection”
General Rules EN 50014
Oil immersed Ex “o” EN 50015
Inside Pressure Ex “p” EN 50016
Construction under sand Ex “q” EN 50017
Explosion-proof housing Ex “d” EN 50018
Increased Safety Ex “e” EN 50019
Intrinsic Safety Ex “i” EN 50020
13. Method Type of Protection
Designed to contain the
explosion (flame) inside the
enclosure
• Ex ’d’ Flammable Enclosure
Designed to prevent any
ignition from arising
• Ex ’e’ Increased Safety
• Ex ’n’ Non Sparking
• Ex ’m’ Encapsulation
Designed to prevent the
flammable mixture reaching
a mean of ignition
• Ex ’q’ Powder Filling
• Ex ’m’ Encapsulation
• Ex ’p’ Pressurization
• Ex ’o’ Oil Immersion
Designed to limit the
ignition energy of the circuit
• Ex’i’ Intrinsic Safety
14. Enclosure Protection Indices
First figure indicates protection against
dangerous access and solid foreign
objects
Index IP Index Second figure indicates protection
against water penetration
Non-protected 0 0 Non-protected
Protected against solid objects 50 mm Ø or
more
1 1 Protected against vertically falling water
drops
Protected against solid objects 12.5 mm Ø or
more
2 2 Protected against vertically falling drops
water enclosure tilted up to 15º
Protected against solid objects 2.5 mm Ø or
more
3 3 Protected against spraying water up to
60º from vertical
Protected against solid objects 1 mm Ø or
more
4 4
5 4
5 5
Protected against splashing water from
any direction
Dust-protected Protected against jets of water from any
direction
Dust-tight 6 6 Protected against powerful jets of water
from any direction
7 Protected against immersion
8 Protected against continuous immersion
15. CENELEC
(European Committee for Electro Technical Standardization)
Some of specialized laboratories recognized by the
EEC in Europe :
• BASEEFA UNITED KINGDOM
• INERIS FRANCE
• CESI ITALY
• DEMKO DENMARK
• ISSeP (INIEX) BELGIUM
• KEMA HOLLAND
• PTB GERMANY
17. Classification of the Hazardous Areas
American Standard
Division 1 The danger can exist during normal operation
Division 2 The danger could exist only in case of breakdown
CLASS I Gas or Vapours
CLASS II Powders
CLASS III Fibers
18. Classification of the Hazardous Areas
European Standard
ZONE 0 An area in which the mixture of explosive gas is constantly
present (ex. The inside of fuel tank).
ZONE 1 An area in which a mixture of explosive gas may be present
during the normal operation of the plant.
ZONE 2 An area in which the mixture of explosive gas is not normally
present, but is only present for brief periods of time.
ZONE 20 An area in which the mixture of explosive powder is constantly
present (ex. The inside of fuel tank).
ZONE 21 An area in which a mixture of explosive powder may be
present during the normal operation of the plant.
ZONE 22 An area in which the mixture of explosive powder is not
normally present, but is only present for brief periods of time.
20. Differences between the European and
north America Methods
• The European Zone 2 and the American Division 2 are easily
seen to be comparable, while the American Division 1 includes
European Zone 1 and Zone 0.
• Its clear that equipment that has been specifically designed
for use in Zone 1 in Europe may not always be suitable for
use in Division 1.
DIVISION 2
DIVISION 1
ZONE 2
ZONE 1
ZONE 0
ICE/EUROPE
USA/CANADA
BREAKDOWN
INTERMITTEN
T PRESENCE
COSTANTLY
PRESENCE
22. Gas Groups
Place of Use Group: Areas Representative Gas
Mines susceptible
to firedamp
I Gaseous mines Methane
Surface industries II A Surface Propane
II B Ethylene
II C Hydrogen Acetylene
Temperature class T1 T2 T3 T4 T5 T6
Maximum Surface 450ºc 300ºc 200ºc 135ºc 100ºc 85ºc
Temperatures
HOT COOLER
25. Explanation of Marking Codes
EEx de II C T6 IP 66
Equipment conforms
to types of protection
Standardized
by CENELEC
(European standards)
Types of
protection used:
d: flameproof
enclosure
e: increased
safety
Used in:
Surface
industries
Gas subdivision:
most critical
category including
hydrogen,
acetylene and
carbon disulphide
Temperature class:
maximum 85ºC
26. The new marking system
• Starting date : July 1, 2003
CE
CE marking which certifies conformity
Notified organization identification
No. (0081 = LCIE)
Distinctive community marking
for equipment usable in explosive atmosphere
Equipment group (surface)
Equipment category (for zone 1)
Gas and vapour
Dust
0081 II 2 G and/or D
Example marking required by the new directive ATEX 94/9/CE
27. Advantages & Disadvantages of
Ex “d” and Ex “e”
Advantages Disadvantages
Ex “d” • capable of withholding a possible
internal explosion and prevent its
transmission to the atmosphere
outside the housing
• higher class of protection
• easily available and cheaper
components
• maintenance more complicated
( e.g. difficult to change fluorescent tubes)
• piped plant (where requested)
complicated
Ex “e” • easy installation
• pleasant appearance
• safety cut-off switch
• high cost of spare parts (components
must be Ex type)
• frequent and costly maintenance
(e.g. seal)
30. BASIC PRINCIPLES FOR HAZARDOUS LOCATION
- EN 50014
• In the hazardous area, it is a common safety
practice and thumb of rules NOT to open
when any electrical equipment are energized.
Therefore, all electrical equipments that need
to be service and maintain must be de-
energized before opening ( all electrical
circuit supplying to the required equipment
should be cut-off as a precautious to prevent
accidental spark that might lead to an
explosion ).
"DO NOT OPEN WHEN ENERGIZED"
31. Zone 1 Versus Zone 2
Zone 1
• Ex’d’ – Cast Aluminium Fitting
Method of Protection –
“CONTAINMENT’
• Ex’e’ – GRP, Stainless Steel,
Aluminium Fitting
“PREVENTION” (no sparks)
Zone 2
• Ex’n’ – GRP, Stainless Steel,
Aluminium Fitting
• Method of Protection –
(non-sparking)
33. Lighting fixtures
• The lighting fixtures, available
with the following methods of
protection:
EEx d – EEx e – EEx n
can be installed both indoor and
outdoor in any hazardous area
34. Pulling and junction boxes
• The pulling and
junction boxes are
manufactured to
contain terminals and
copper bars according
to gas group IIB or IIC
and, on request, to IP
66 which allows to
install the boxes in any
kind of hazardous area
35. Junction boxes Ex “e”
• The increased safety
junction boxes are
designed and
manufactured to contain
terminals and non-
sparkling equipment. They
comply with European
standard EN 50019 and
can be built in alluminium
alloy, stainless steel and
glass reinforced polyester
38. Control stations
* A wide range of
control stations,
studied for any kind of
possible application in
electrical installations
* Their particular
stoutness allows the
use in any kind of
industrial environment
39. Instrument housings and signallers
• Studied to support the
activity of control, the
instrument housings
and the signallers are
designed to allow the
immediate check of
the process status,
both visually and
acoustically
40. Thermo-magnetic breakers
• To start electric motors
and to grant their
thermo-magnetic safety,
A wide range of
equipment with a wide
range of usable power
41. Plugs and receptacles
• Plugs and receptacles in
EEx-d execution are
complete with an
interlocked automatic
switch in compliance with
EN norms requirement.
• The different models are
suitable to be used for
lighting installation or
motive power feeding
42. Weather-proof equipment
• Weather-proof enclosures
are suitable to contain
every kind of electrical
and electronic equipment
• They are designed to be
used in any heavy-duty
industrial environment
thanks to their particular
stoutness
43. Cable Glands
• The wide range designed
and manufactured both
explosion-proof and
weather-proof cable
glands
• The methods of protection
used are :
EEx d – EEx e – EEx i -
IP
to cover any kind of safety
requirement of an
electrical installation
44. Grounding equipment
• A grounding system
protects the electrical
installation from
electrostatic and
atmospheric
discharges
• Safety production
includes a wide range
of accessories for
grounding nets
45. The directive ATEX 100
the new european
directive for
explosion-proof
equipment
47. European Standards of Product
CENELEC SERIES EN 50014 - EN 50020
FIRST EUROPEAN DIRECTIVE 18/12/75
ACCEPTED BY ITALY WITH DPR 727 -1982
48. The New ATEX 100
The ATEX 94/9/CE also known as ATEX 100:
• Controls the trading and the installation of
Explosion- Proof equipment
• Introduces the application of CE mark in addition
to the community EX mark
• Fixes to 30/06/2003 the term when the products
introduced on the market will have to be in
accordance with the new community directives
49. Essential Safety Requirements
ESR means the Essential Safety Requirements
to which the equipment, manufactured so to be
used into a potentially explosive atmosphere,
must be in conformity
50. Principle of integrated safety
Conditions for the inspections
and maintenances
Environmental conditions
Marking
Instructions
Choice of materials
Designing and manufacturing
Sources of ignition
Sparks
Flames
Electrical arcs
High surface
temperatures
Acoustic energy
Radiations
Software risks
Explosive atmosphere for
gases and e vapours
Explosive atmosphere for
dust
Essential Safety Requirements
51. The ESR in the electrical sector
In the electrical sector, existing from many
years complete technical norms, the
application of ESR will be a mere
theoretical exercise
52. Classification of Equipments
EQUIPMENT
GROUP
CATEGORY OF
EQUIPMENT
EXPLOSIVE
ATMOSPHERE
INFLAMMABLE
SUBSTANCES
LEVEL OF
PROTECTION
FAULT
PROTECTION
I
Mines
M1 Present Methane, dust Very high level
2 types of
protection
M2
Probable
presence
Methane, dust High level
1 type of
protection
II
Surface
1
Continous
Presence
Gas, vapour,
mist, dust
Very high level
2 types of
protection
2
Intermittent
presence
Gas, vapours,
mist, dust
High level
1 type of
protection
3
Occasional
presence
Gas, vapour,
mist, dust
Normal
Required level
of protection
53. Conformity Evaluation
• Electrical equipment of category 1 and 2
EC Test of Type (certification by a Notified Body)
Supervision on the production
Checking of the manufacturer’s quality system done
by the Notified Body
• Electrical equipment of category 3
Internal check of production
Declaration of conformity
Editing of technical documentation
54. Marking
• Name and address of manufacturer : Fondisonzo Italia
• Type, serial number, year : EVA 2015 – AB12345 - 2003
• CE marking : CE
• Group (Gas and/or dust) : Ex 2G 2D
• ID number of Notified Body : 4583
• Types of protections : EEx d IIC T6
• Number of certificate : ATEX Cesi 48/01
55. Expected problems
• Incomprehensions between manufacturers
and end-users
• Marking of current products
• Selling off of stock
• Time and costs of renewal of certificates
56. Advantages
• Supervision on the products
• Supervision on manufacturing
processes
• Removal of obsolete and not serious
equipment
• Maximum reliability of products with a
great advantage of safety