Flowserve MP1 Sier-Bath - Manual (Page 19)

MP1 USER INSTRUCTIONS ENGLISH 26999958 – 10-12
Page 19 of 48 flowserve.com
particularly important on large or high-speed
pumps which should have a minimum of two
diameters of straight pipe on the pump suction
between the elbow and inlet flange. See section
10.3 Additional sources of information for more
detailed technical explanations on this piping
design requirement.
g) Inlet strainers, when used, should have a net `free
area' of at least three times the inlet pipe area.
h) Fitting an isolation valve will allow easier
maintenance.
i) Never throttle pump on suction side.
4.7.3 Discharge piping
A non-return valve should be located in the discharge
pipework to protect the pump from excessive back
pressure and hence reverse rotation when the unit is
stopped.
Pipework reducers should have a maximum total angle
of divergence of 15 degrees.
Fitting an isolation valve
will allow easier maintenance.
4.7.4 Relief Valves
Twin Screw Pumps are of the positive
displacement type; considerable pressure will develop
in the discharge piping and inside of the pump if
discharge line is blocked through closing of valve, etc.
It is therefore necessary for the protection of the pump
and discharge line to provide a relief valve. This should
be piped back to the suction tank and not to the
suction line.
4.7.5 Auxiliary piping
4.7.5.1 Drains
Pipe pump casing drains to a convenient disposal
point, according to the appropriate safety, health and
environment policies of the location for the pump’s
application.
4.7.5.2 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 section 8.2 General arrangement
drawing.
Special seals may require different auxiliary piping to
that described above. Consult separate 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.
4.7.6 Final checks
Check the tightness of all bolts in the suction and
discharge pipework. Check also the tightness of all
foundation bolts.
4.8 Pressure gauges
It is recommended that suitable suction and discharge
pressure gauges be provided. Pressure readings are
essential to resolving operational problems and are
useful for monitoring pump performance.
4.9 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.
4.10 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 there is 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