Flowserve Worthington WXB - Manual (Page 17)

WXB USER INSTRUCTIONS ENGLISH - 07/14
Page 17 of 51
4.5.6 Balancing line
The pump must have a balancing line back to suction
for proper axial thrust balancing. This could be
a) an internal balancing line. This is usually used for
water services up to 80°C (176°F).
b) a connection for an external balancing line. This
is usually used for hot water and hydrocarbon
service.
Refer to GA drawing for type of balancing
line.
4.5.6.1 Design guidelines for external balancing
line
The balancing line shall be led back to the suction
vessel. The line must be open during operation to
avoid damage of the equipment. The maximum back
pressure created in the balance line, shall not exceed
2 bar (29 psi) above suction pressure. Therefore the
balance line shall be designed for a pressure loss of
max. 1 bar (14.5 psi). The following table gives the
expected balance flow rates:
2 WXB 6 m³/h (26.4 gpm)
3WXB 8 m³/h (35.2 gpm)
4WXB 10 m³/h (44.4 gpm)
6WXB 11 m³/h (48.4 gpm)
These flowrates shall be used for the piping design.
Flashing of the fluid in the balancing line shall be
avoided, therefore the installation of an anti-flashing
orifice at the end of the balancing line is
recommended.
Design and manufacturing of the balance
line is not within the responsibility of FPD.
4.6 Electrical connections
Electrical connections must be made by a qualified
Electrician in accordance with the relevant local
national and international regulations.
It is important to be aware of the EUROPEAN
DIRECTIVE on hazardous areas where compliance
with IEC60079-14 is an additional requirement for
making electrical connections.
It is important to be aware of the EUROPEAN
DIRECTIVE on electromagnetic compatibility when
wiring up and installing equipment on site. Attention
must be paid to ensure that the techniques used
during wiring/installation do not increase
electromagnetic emissions or decrease the
electromagnetic immunity of the equipment, wiring or
any connected devices. If in any doubt contact
Flowserve for advice.
The motor must be wired up in accordance with the
motor manufacturer's instructions (normally supplied
within the terminal box) including any temperature,
earth leakage, current and other protective devices
as appropriate. The identification nameplate should
be checked to ensure the power supply is
appropriate.
A device to provide emergency stopping must
be fitted.
If not supplied pre-wired to the pump unit the
controller/starter electrical details will also be supplied
within the controller/starter.
For electrical details on pump sets with controllers
see the separate wiring diagram.
See section 5.5, Direction of
rotation before connecting the motor to the electrical
supply.
4.7 Final shaft alignment check
After connecting piping to the pump, rotate the shaft
several times by hand to ensure there is no seizure
and all parts are free.
Recheck the coupling alignment, as previously
described, to ensure no pipe strain. If pipe strain
exists, correct piping.
5.0 COMMISSIONING START-UP,
OPERATION AND SHUTDOWN
These operations must be
carried out by fully qualified personnel.
5.1 Precommissioning procedure
a) The bearing housing must be filled with the
indicated oil. Check also the oil level.
b) The pump must be completely filled with liquid to
avoid running dry and to guarantee a correct
performance of the pump.
c) During filling the pump shall reach the specified
temperature, so pumps for hot liquids (T > 150 °C
(302 °F)) shall be warmed up by preflushing.
d) Check the sense of rotation of the pump (Coupling
spacer dismantled).
Sense of rotation is clockwise viewed to the drive
end of the pump.
e) The pump rotor and the shaft seal must be in
correct axial position. Mounting plates of
mechanical seal must be locked at the seal gland
in open position. Drive-collar of the mechanical