BEDU S Series, Operating And Maintenance Manual, Page: 13 / 40

4.4 DRIVE UNIT AND ACCESSORY ASSEMBLY
4.4.1 Motor
The Company installs EC approved electric motors, of power compatible with that required
by the pump, selected according to the desired operating conditions and environmental
characteristics. In particular if the pump unit is required to operate in explosive atmosphere,
the motor is chosen in explosion-proof execution
(we remind that, to be used within the
European Union, also the execution of the pump and the relevant fittings must com-
ply with directive 94/9/EC).
4.4.2 Installation of safety and control devices
If specifically requested in the order form, the Company provides the pump with the relief
valve, which must be calibrated to protect the pump from damage. Once it has been proper-
ly calibrated, the valve must not be tampered with in any way, since volumetric pumps can
reach quickly, with the delivery closed, extremely high pressure values, with consequent
very serious danger.
Any pressure adjustment shall be compulsorily made with the pump stopped and de-
pressurized.
The User shall install a pressure gauge in the pump outlet, upstream of the relief valve; it is
advisable to install a vacuum gauge near the pump inlet.
In case also a safety valve is installed on the system, make sure that its calibration pressure
differs considerably from the one of the relief valve not to generate dangerous resonance
phenomena (pipe and/or valve break).
4.5 ELECTRICAL CONNECTIONS, CONNECTION CABLES
The machine shall be connected to the external ground protection system by the appropriate
terminal, which must be identified by the PE letter. Connection cables shall be properly sized
and insulated. Before energizing the machine, always verify that the mains voltage and fre-
quency are compatible with those of the motor.
4.6 PIPING
4.6.1 General
Pipes shall have a suitable diameter to allow a regular flow with low pressure losses. There-
fore, we recommend to use, at least for the suction line, pipes with inner diameter equal to
or greater than that of the pump inlet, mostly when the viscosity level becomes considerable.
To minimize pressure losses in the circuit, we recommend to avoid, as much as possible,
abrupt variations of section and direction (curves) along the pipe run, particularly in the suc-
tion line.
4.6.2 Forces and moments which operate on suction and delivery flanges.
As general rule it would be necessary to interpose flexible vibration damping sections be-
tween the pump and the system piping; therefore, we recommend to verify that the flanges
of the connection pipes are always placed, in free position, with the planes parallel to those
of the flanges of the suction and delivery nozzles to avoid that, after fastening them, forces
and moments of excessive value are generated.
In any case, the User shall make sure that the loads induced on the pump flanges, under the
most critical operating conditions, do not exceed the values prescribed by Standards UNI
EN ISO 14847.
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