WDX USER INSTRUCTIONS ENGLISH 71576322 06-05
Page 7 of 46
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1.6.4.2 Marking
An example of ATEX equipment marking is shown
below. The actual classification of the pump will be
engraved on the nameplate.
II 2 GD c IIC 135 ºC (T4)
Equipment Group
I = Mining
II = Non-mining
Category
2 or M2 = High level protection
3 = normal level of protection
Gas and/or Dust
G = Gas; D= Dust
c = Constructional safety
(in accordance with prEn13463-5)
Gas Group (Equipment Category 2 only)
IIA
–
Propane (typical)
IIB
–
Ethylene (typical)
IIC
–
Hydrogen (typical)
Maximum surface temperature (Temperature Class)
(see section 1.6.4.3)
1.6.4.3 Avoiding excessive surface temperatures
ENSURE THE EQUIPMENT TEMPERATURE
CLASS IS SUITABLE FOR THE HAZARD ZONE
Pumps have a temperature class a s stated in the
ATEX Ex rating on the nameplate. These are based on
a maximum ambient of 40 °C (104 °F); refer to
Flowserve for higher ambient temperatures.
The surface temperature on the pump is influenced by
the temperature of the liquid handled. The maximum
permissible liquid temperature depends on the
temperature class and must not exceed the values in
the table that follows.
The temperature rise at the seals, bearings and due to
the minimum permitted flow rate is taken into account
in the temperatures stated.
Temperature
class to
prEN 13463-1
Maxi mum
surface
temperature
permitted
Temperature limit of liquid
handled (* dependi ng on
material and c onstruc tion
variant - c hec k whic h is
lower)
T6
T5
T4
T3
T2
T1
85 °C (185 °F)
100 °C (212 °F)
135 °C (275 °F)
200 °C (392 °F)
300 °C (572 °F)
450 °C (842 °F)
Consult Flows erve
Consult Flows erve
115 °C (239 °F) *
180 °C (356 °F) *
275 °C (527 °F) *
400 °C (752 °F) *
The responsibility for compliance with the specified
maximum liquid temperature is with the plant
operator.
Tem perature classification “Tx” is used when the liquid
temperature varies and the pump could be installed in
different hazardous atmospheres. In this case the user
is responsible for ensuring that the pump surface
temperature does not exceed that permitted in the
particular hazardous atmosphere.
If an explosive atmosphere exists during the
installation, do not attempt to check the direction of
rotation by starting the pump unfilled. Even a short run
time may give a high temperature resulting from
contact between rotating and stationary components.
Where there is any risk of the pump being run against a
closed valve generating high liquid and casing external
surface temperaturesit is recommended that users fit
an external surface temperature protection device.
Avoid mechanical, hydraulic or electrical overload by
using motor overload trips, temperature monitor or a
power monitor and make routine vibration monitoring
checks.
In dirty or dusty environments, regular checks must be
made and dirt removed from areas around close
clearances, bearing housings and motors.
1.6.4.4 Preventing the build up of explosive
mixtures
ENSURE PUMP IS PROPERLY FILLED AND
VENTED AND DOES NOT RUN DRY.
Ensure pump and relevant suction and discharge
pipeline system is totally filled with liquid at all times
during the pump operation, so that an explosive
atmosphere is prevented. In addition it is essential to
make sure that seal chambers, auxiliary shaft seal
systems and any heating and cooling systems are
properly filled.
If the operation of the system cannot avoid this
condition the fitting of an appropriate dry run protection
device is recommended (eg liquid detection or power
monitor).
To avoid potential hazards from fugitive emissions of
vapour or gas to atmosphere the surrounding area
must be well ventilated.
