Flowserve LNGT - Manual (Page 23)

LNGT USER INSTRUCTIONS ENGLISH 00083107 11-07
®
4.4.4 Discharge piping
See section 4.6.2 for typical pipe work design.
A non-return valve should be located in the
discharge pipe work to protect the pump from
excessive back pressure and hence reverse
rotation when the unit is stopped.
Pipe work reducers should have a maximum total
angle of divergence of 9 degrees.
Fitting an isolation valve will allow easier
maintenance.
4.4.5 Auxiliary piping
4.4.5.1 Drains
Pipe pump casing drains and gland leakage to a
convenient disposal point.
4.4.5.2 Pumps fitted with packed gland
When suction pressure is below ambient pressure it is
necessary to feed the gland packing with liquid to
provide lubrication and prevent the ingress of air.
This is normally achieved with a supply from the
pump discharge volute to the stuffing box. An orifice
plate is fitted into the supply line [flanges or unions] to
control the pressure to the gland/stuffing box.
If the pumped liquid is dirty and cannot be used for
sealing, a separate clean compatible liquid supply
to the gland at 1 bar [15 psi] above suction
pressure is recommended.
4.4.5.3 Pumps fitted with mechanical seals
Single seals requiring re-circulation will normally be
provided with the auxiliary piping from pump casing
already fitted.
If the seal requires an auxiliary quench then a
connection must be made to a suitable source of
liquid flow, low pressure steam or static pressure
from a header tank. Recommended pressure is
0.35 bar [5 psi] or less. Check General
arrangement drawing.
Special seals may require different auxiliary piping
to that described above. See Supplementary User
Instructions, Seal User Instructions and or
Flowserve if unsure of correct method or
arrangement.
For pumping hot liquids, to avoid seal damage, it is
recommended that any external flush/cooling
supply be continued after stopping the pump.
4.4.6 Final checks
Check the tightness of all bolts in the suction and
discharge pipe work. Check also the tightness of
all foundation bolts.
4.5 Final shaft alignment check
After connecting piping to the pump, rotate the
shaft several times by hand to ensure there is no
binding and all parts are free.
Recheck the coupling alignment, as previously
described, to ensure no pipe strain. If pipe strain
exists, correct piping.
4.6 Electrical connections
Electrical connections must be made
by a qualified Electrician in accordance with
relevant local national and international regulations.
It is important to be aware of the EUROPEAN
DIRECTIVE on potentially explosive 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