Pompa ad Ingranaggi - Serie MX
Gear Pump - MX Series
33
The pump operating temperature in normal working conditions is about 80°C. In special
pump versions, working temperatures of 180°C and more may be achieved. To protect per-
sonnel from dangers due to the temperatures reached during the operation of the machine,
in the event of accidental contact (burn), the User must reduce the external pump tempera-
ture by means of insulation plates, coatings, screens, barriers, etc. As limit reference tem-
perature for the contact surface it is advisable to take 55°C. Below this value, for hot smooth
surfaces in bare metal, there is no burn threshold. For a detailed knowledge of this problem
in relation to different particular cases, the User can read the standard UNI EN ISO 13732-
1:2009, where burn thresholds are specified for several types of surface according to the
“surface temper
ature -
contact time” parameters.
Liquids to be pumped must not contain abrasive or solid suspension as this will greatly re-
duce the pump life. At this purpose we recommend the installation of a properly sized filter
on the suction line if solids may be present.
When pumps are installed in parallel, the suction lines should be adequately separated to
prevent unnecessary turbulence.
3.3
PROTECTION DEVICE
The coupling guard installed by the Manufacturer is made of a strong metal plate, fastened
to the baseplate by screws, duly shaped to prevent fingers from coming into contact with
moving parts. It can be removed only by using a proper tool.
3.4
ADDITIONAL DESCRIPTION OF ACCESSORIES
3.4.1
Seal parts
The pump is usually supplied equipped with mechanical seal. If the Customer requires a
particular type of seal, Pompe Cucchi S.r.l. installs the desired seal after verifying if its di-
mensions are compatible with those of the pump. In case the Customer requires only the
seal mark, the Company leaves the Manufacturer to select the type of seal, by giving infor-
mation about the pumped liquid.
Among the seals used we can mention the following:
-
Packing rings
- Single mechanical seal
- Double tandem mechanical seals with tank and pressureless flowing liquid
- Double opposed mechanical seals with external pressurized flowing liquid
These last must be installed when the pumped product has characteristics which prevent it
from being used as flowing source or for greater safety (visual inspection).
The tank for tandem mechanical seals is not pressurized and it is used to avoid dry opera-
tion of the external seal and visually detect any possible leakage of the internal mechanical
seal.
For magnetic drive pumps sealing is only ensured by static gaskets, since the pump shaft is
completely enclosed within the pump body.
3.4.2
Safety valve
The pump can be provided with safety valve, with adjustable calibration, installed on the rear
cover.
When the calibration pressure has been reached, overcoming the reaction of the contrast
spring, the valve starts to open, letting the pump delivery and suction sides to communicate.
The purpose of the valve is simply to protect the pump from accidental overpressure peaks;
its extended opening may damage the pump.