Flowserve FRBH User Manual
Page 7

FRBH, FRBHX AND FRBHS USER INSTRUCTIONS ENGLISH 71569178 10-04
Page 7 of 54
®
 
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
surf ace
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. 
 
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 a power 
monitor). 
 
To avoid potential hazards from fugitive emissions of 
vapour or gas to atmosphere the surrounding area 
must be well ventilated. 
 
1.6.4.5 Preventing sparks 
To prevent a potential hazard from mechanical
contact, the coupling guard must be non-sparking and 
anti-static for Category 2. 
 
To avoid the potential hazard from random induced 
current generating a spark, the earth contact on the 
baseplate must be used. 
 
Avoid electrostatic charge: do not rub non-metallic 
surfaces with a dry cloth
;
ensure cloth is damp.
 
The coupling must be selected to comply with 94/9/EC 
and correct alignment must be maintained. 
 
1.6.4.6 Preventing leakage 
The pump must only be used to handle liquids for
which it has been approved to have the correct 
corrosion resistance. 
 
Avoid entrapment of liquid in the pump and associated 
piping due to closing of suction and discharge valves, 
which could cause dangerous excessive pressures to 
