Flowserve Worthington WXB - Manual (Page 6)

WXB USER INSTRUCTIONS ENGLISH - 07/14
Page 6 of 51
Where Flowserve has supplied only the bare shaft
pump, the Ex rating applies only to the pump. The
party responsible for assembling the pump set shall
select the coupling, driver and any additional
equipment, with the necessary CE Certificate/
Declaration of Conformity establishing it is suitable for
the area in which it is to be installed.
The output from a variable frequency drive (VFD) can
cause additional heating affects in the motor and so,
for pump sets with a VFD, the ATEX Certification for
the motor must state that it covers the situation where
electrical supply is from the VFD. This is particular
requirement still applies even if the VFD is in a safe
area.
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 IIC135ºC (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 EN13463-5)
b = Control of ignition source
(in accordance with EN13463-6)
Gas Group
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 as stated in the
ATEX Ex rating on the nameplate. These are based
on an ambient in the range of -80 to +55 ºC (-112 to
+131 ºF); refer to Flowserve for ambient
temperatures outside this range for this product.
The surface temperature on the pump is influenced
by the temperature of the liquid handled. The
maximum permissible liquid temperature depends on
the ATEX temperature class and must not exceed the
values in the table that follows.
Temperatur
e class to
EN 13463-1
Maximum
surface
temperature
permitted
Temperature limit of liquid
handled (* depending on
material and construction
variant - check which 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 Flowserve
Consult Flowserve
115 °C (239 °F) *
180 °C (356 °F) *
275 °C (527 °F) *
400 °C (752 °F) *
* The table only takes the ATEX temperature class into
consideration. Pump design or material, as well as component
design or material, may further limit the maximum working
temperature of the liquid.
The temperature rise at the seals and bearings and
due to the minimum permitted flow rate is taken into
account in the temperatures stated.
The responsibility for compliance with the
specified maximum liquid temperature is with the
plant operator.
Temperature classification “Tx” is used when the
liquid temperature varies and when the pump is
required to be used in differently classified potentially
explosive
atmospheres. In this case the user is
responsible for ensuring that the pump surface
temperature does not exceed that permitted in its
actual installed location.
Do not attempt to check the direction of rotation with
the coupling element/pins fitted due to the risk of
severe 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 temperatures it is recommended that
users fit an external surface temperature protection
device.
Avoid mechanical, hydraulic or electrical overload by
using motor overload trips or a Power Monitor and
make routine vibration monitoring.
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 THE PUMP IS PROPERLY FILLED
AND VENTED AND DOES NOT RUN DRY