EN – 31
EN
Operation
Operation of gas ballast
Regeneration of
pump oil
In a pump stored with the same oil for a long time, condensed vapors may contaminate
the oil bath and affect performance. This is also the case after pumping vapors and
when the oil appears cloudy or discolored through the sight glass.
• Run the pump, shutting it off from the system at the inlet by a valve or a plug.
• Open the gas ballast and allow the pump to operate for 1/2 hour to 1 hour, or
longer if the oil remains cloudy. This operation accelerates the temperature rise of the
pump while eliminating residual vapors present in the oil bath.
Pumping condensable
vapors
To pump with condensable products, it is necessary to operate with a hot pump. For
this, isolate the pump from the system and allow it to operate for 1/2 hour with the
gas ballast open, or 1 hour (if possible) with the gas ballast closed. When the oil bath is
hot, the condensation of vapors in the pump is reduced or prevented.
Choice of pump and system
The pump’s capacity to eliminate condensable vapors is related to their type, the pump
temperature and the quantity of air introduced by the gas ballast.
Care should be taken to limit the inlet pressure of the pump to its maximum admissible
water vapor pressure with the pumped product. This is obtained by reading the pump
characteristic table for water vapor (
see pages 11 and 12
).
The use of cold traps or condensers are recommended when large quantities of vapors
are to be extracted.
Caution : don’t forget to regenerate the traps. Excessively intense or prolonged
pumping may cause the products condensed in the trap to be evaporated a
second time.
Choice of oil
Choose an oil which facilitates the separation of pumped products which may be
condensed in the oil bath (anti-emulsion oil for water-based compounds, etc.)
(
see page 17
).
Assembly
The condensation of vapors at the pump exhaust is
reduced if:
• The pump and oil temperature are high.
• The pressure at the exhaust is as low as possible
(removal of the oil mist eliminator, connection to
an evacuation duct...).
• The condensates are collected separately from
the oil bath and do not block the exhaust duct.
For this:
• Avoid using any vertical ducting which promotes
the condensation of products and the return of
these products to the pump.
• Use a condensate collector.
• We do not recommend an oil mist eliminator
when pumping condensable vapors: if it is
essential, do not connect it directly to the pump
exhaust but place it outside the condensation
zone.
• Remove the stop valve from the pump exhaust
(
SD series
).
• Connect the exhaust to a mechanical device
creating a negative pressure from 0.75 Torr to
1.5 Torr (0.1 to 0.2 bar).
Inl.
Exh.
Inl.
Exh.
Condensat trap
