Flowserve Twin Screw Rotary - Manual (Page 7)

TWIN SCREW PUMPS. ORIGINAL USER INSTRUCTIONS. ENGLISH. 71569243 – 07/10
Page 4 of 53
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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 EN13463-5)
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 as 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 and bearings and
due to the minimum permitted flow rate is taken into
account in the temperatures stated.
Temperature
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 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.
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 temperatures it 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 THE PUMP IS PROPERLY FILLED
AND VENTED AND DOES NOT RUN DRY
Ensure the 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.