www.sitspa.com
TRASCO
®
- User and Maintenance Manual
114.02 - Rev. 2 - 2
nd
March 2020
Approved by: SIT S.p.A.
26
5.2 ATEX equipment classification
5.3 Appropriate use of TRASCO
®
couplings in ATEX zones
Below is the classification of equipment and protection systems according to the ATEX Directive 2014/34/EU.
The analysis carried out by SIT S.p.A. led to the conclusion that the couplings can be used in the presence of flammable gases,
vapours, mists or combustible dusts according to the following scheme:
• Gases, vapours or mists in zones 1 and 2 (not suitable for zone 0)
• Dusts in zones 21 and 22 (not suitable for zone 20)
• Equipment in group I (mining) and categories M2 (not suitable for category M1)
• Equipment in group II (gas) and categories 2 and 3 (not suitable for category 1)
• Explosion group IIC, including groups IIA and IIB
• Equipment in group III (dust) and categories 2 and 3 (not suitable for category 1)
• Explosion group IIIC, including groups IIIA and IIIB
Table 5.2 - ATEX groups and categories classification
5.3.1 Gas temperature classes for Group II equipment
and maximum surface temperature for equipment of Group III
The table indicates the temperature above which the gases, belonging to the respective class, ignite.
The ambient or operating temperature of the couplings was determined by SIT according to the characteristics of the coupling and
taking into account a safety factor equal to 20 K. For every class of temperature, there is a safety factor of 5 K.
The maximum surface temperature of 110 °C refers to the applications with potential deposit of inflammable dust.
The environment and operating temperature are limited to 90 °C due to the limits of the compound of the spiders.
TEMPERATURE CLASS
MAXIMUM SURFACE TEMPERATURE
[°C]
AMBIENT OR OPERATING TEMPERATURE T
s
[°C]
T4
110
-30 °C < Ta < 90 °C
T5
95
-30 °C < Ta < 75 °C
T6
80
-30 °C < Ta < 60 °C
Table 5.3 - Gas temperature classes
GROUP
EPL
CATEGORY
RISK LEVEL
PROTECTION CHARACTERISTICS
OPERATING CONDITIONS
GROUP I
(mining
industry)
Ma
M1
Very high
Two independent means of protection or
safety ensured even in the event of two faults
occurring independently of each other.
The equipment remains connected
to the power supply and in operation
even in the presence of explosive
atmospheres.
Mb
M2
High
Suitable for normal operation and for severe
operating conditions. Where appropriate,
also suitable for frequent disturbances or
defects which normally need to be taken
into account.
The equipment is disconnected from
the power supply in the presence of
explosive atmospheres.
GROUP II
GAS
(industry,
except mining
industry)
Ga
1
Very high
Two independent means of protection or
safety ensured even in the event of two faults
occurring independently of each other.
The equipment remains connected to
the power supply and in operation in
zones 0, 1, 2.
Gb
2
High
Suitable for normal operating conditions
and for frequent disturbances or devices in
which faults normally need to be taken into
account.
The equipment remains connected to
the power supply and in operation in
zones 1, 2.
Gc
3
Normal
Suitable for normal operation.
The equipment remains connected to
the power supply and in operation in
zones 2.
GROUP III
DUSTS
(industry,
except mining
industry)
Da
1
Very high
Two independent means of protection or
safety ensured even in the event of two faults
occurring independently of each other.
The equipment remains connected to
the power supply and in operation in
zones 20, 21, 22.
Db
2
High
Suitable for normal operating conditions
and for frequent disturbances or devices in
which faults normally need to be taken into
account.
The equipment remains connected to
the power supply and in operation in
zones 21, 22.
Dc
3
Normal
Suitable for normal operation.
The equipment remains connected to
the power supply and in operation in
zones 22.
