VARISCO GS Series, Operating And Maintenance Manual

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Pompa ad ingranaggi - Serie GS, GK
Gear pump - GS, GK Series
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5.3.2 Acoustic insulation
Sound emission values are specified in this manual. The User should always verify if the
regulations of his own country prescribe, in relation to the frequency of exposure to emission
values, the use of individual protection devices. If it is, he must comply with the require-
ments contained in the above-mentioned regulations to protect the operator’s health and
safety.
5.3.3 Splash-proof cover
In the event the liquid being pumped is dangerous, the operator must be in any case pro-
tected against the risk of any accidental contact with jets of liquid by wearing appropriate in-
dividual protection devices.
5.3.4 Regulation on the electric components
We remind that in accordance with Standard IEC 60204-1, as power disconnecting switch, a
plug/socket combination is allowed for a machine with rated power equal to or lower than
16 A and a total power equal to or lower than 3 kW.
5.4 COMMISSIONING
5.4.1 Initial commissioning
- Ensure that the pump unit is properly earthed.
- In case the pump is equipped with heating jacket, it is necessary to operate this last up to
reach the normal operating temperature and gradually start the liquid pumping up to reach
the operating conditions in thermal equilibrium.
- Verify that suction pipes are properly joined one another to avoid air infiltrations which
would prevent the pump from priming.
- Check that siphons are not created in the suction pipes so that pump can completely re-
move the air. In this case, if the air is not completely removed then the flow rate may de-
crease and the noise level may increase although the pump has taken in the liquid, with
consequent premature deterioration of bearing bushes and moving parts.
- Where applicable, verify that the pipes for the external flow of mechanical seal are proper-
ly connected.
- Verify the proper operation of the relief valve; to do so it is necessary to gradually increase
pressure, by acting on the valve located on the discharge pipe, up to reach the expected
calibration value. Now, after a further rotation of the valve, the discharge pressure shall
remain lower than the calibration value. Otherwise, after stopping the machine and de-
pressurizing the pump, it is necessary to disassemble the valve cap
m , remove the gas-
ket below
o
, loosen the nut
p
and rotate counterclockwise the pre-load adjusting screw
n
(clockwise to increase the pre-load of the spring
q
). Retighten the lock nut
p
, inter-
pose the gasket o and rescrew the protection cap m . The adjusting screw n is not
equipped with retainer, therefore it is necessary to pay attention, when unscrewing
it, not to cause a leakage of the fluid being pumped.
5.4.2 Startup after shutdowns
The most common case in which the pump may stop working - apart from the power supply
failure (black out) – is when the electric motor overcharge protection comes into operation.
In this case, before starting the pump examine the causes which triggered the activation of
the protection and remove them.
In magnetic drive pumps, it may happen that, once the maximum transmissible torque value
has been exceeded, the pump stops while the motor is idling. In this case, it is necessary to
stop immediately the motor, wait until the inner magnet cover (which became hot as a result
of eddy currents) is cooled and restart the motor after troubleshooting