EBARA EVM Série Manuel D'instruction page 10

EVM atex.qxp:Evm atex
Under these conditions, the seal is guaranteed for
continuous 24-hour operation for 6 months.
When replacing or controlling the seal, please refer
to the retailer or the help service.
7.3. PUMP OPERATION WITH AN
OBSTRUCTED/CLOSED DELIVERY VALVE
FIGURE 5 shows the assembly drawing of the flow
rate measurer (Mp) which must be assembled at
delivery so that the pump (P) blocks when the flow
rate falls below 5% of the maximum return point.
In this case the electric contact (C) deactiva-
tes/activates, disconnecting the electric power
supply and rendering the pump safe.
This value guarantees respect of temperature classifica-
tion on the internal and external surfaces of the pump.
7.4. DAMAGE CAUSED BY CHEMICAL NON
COMPATIBILITY BETWEEN LIQUID
AND COMPONENTS
Check the chemical compatibility between the fluid
and the pump parts.
7.5. CAVITATION
It is important to always check correct pump sizing
(therefore it is essential to verify the value needed
by the pump using the NPSH curves. These curves
can be found in the product general catalogues).
7.6. HOT FLUIDS
TAB. 2 gives the maximum temperature that the
fluid can reach in each temperature classification
(these values are permitted respecting the condi-
tions expressed in point 5.3 NOTES).
It is important to install a reading device in order to
guarantee the maximum temperature of the fluid.
Should the limit value indicated in TAB. 2 be excee-
ded, a release apparatus should switch the pump off.
The temperature measuring instrument must be in
conformity with the UNI EN 13463-1 norm (cate-
gory 4 of the Machines Directive) and carry an
ATEX marking that is compatible with that of the
pump. The switchboard which guarantees inter-
vention when the limit values are exceeded must
be FAILURE SAFE.
TAB.1: Classification of the maximum surface tem-
perature for apparatuses belonging to group II G (in
accordance with the EN 13463-1 norm)
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Temperature Maximum pump
classification
temperature
T1
T2
T3
T4
T5
T6
TAB. 2: Maximum temperature of the fluid in ac-
cordance with the temperature classification
Maximum temperature of the fluid Temperature
[°C]
120 *)
120 *)
120 *)
80
*) Technical datum given in paragraph 7.1 of the
User and Maintenance Manual of the EVM product.
8. MAINTENACE AND REPAIRS
Please refer to paragraph of the instruction book-
let for information on maintenance and repairs.
In addition, the pump must never be cleaned using
dry cloths (rubbing with dry cloths made of pure
polyamide material or cotton, for example, can
cause electric discharges).
Some EVM pump models have a bearing on the
joint. No maintenance needs to be carried out on
the bearings, which should work for 10,000 hours
at a temperature of 40°C without problems.
When replacing or controlling the bearings, the
user must contact the retailer or the help service.
The same is true for the seal (para. 7.2).
Verify, proportionally to the operation conditions,
that the compression ratio is lower than the spon-
taneous ignition limit of the processed fluid.
Correct motor alignment is indispensable for pre-
venting vibrations and faulty bearings.
Gas or vapour
surface mix
ignition
(C°) temperature (°C)
450 >450
300 >300
200 >200
135 >135
100 >100
85 >85
classification
T1
T2
T3
T4