Rubber valves, Vacuum pump, Exhaust filter – Martin Christ Alpha 2-4 LDplus User Manual
Page 58: Cleaning

58 Maintenance and Service
Operating Manual Freeze Dryer ALPHA 1-4 LDplus / ALPHA 2-4 LDplus
7.1.4. Rubber Valves
Special attention must be paid to the rubber valves. If the valves are 
stiff, they must be dismantled, cleaned, slightly greased with 
vacuum grease and reassembled. 
7.1.5. Vacuum Pump
For maintenance of the vacuum pump please refer to the separate 
operating manual. 
Additionally, we would like to emphasise the following points: 
The oil level of the vacuum pump must be regularly checked using 
the inspection glass (in case of continuous operation at least once a 
week). Top up oil to the required level via the oil inlet. For topping-
up see the operating manual of the pump. 
The first oil change must be carried out after approx. 100 operating 
hours. Subsequent oil change intervals depend on the operating 
conditions. In general, an oil change is necessary after approx. 500 
to 1000 operating hours. 
The oil change should always be carried out with warm pump.
7.1.6. Exhaust Filter
If the unit is equipped with an exhaust filter (necessary if the 
exhaust gases cannot be extracted into the open air or into a vent) 
take care that the condensate in the filter does not rise too high. 
The condensate is drained using a waste oil drain screw at the filter. 
Please refer to separate operating manual! 
7.1.7. Cleaning
7.1.7.1.
Cleaning of the Freeze-dryer
Use soap water or other water-soluble, mild agents for cleaning of 
the freeze-dryer. Avoid corrosive and aggressive substances. Do 
not use alkaline solutions or solvents or agents with abrasive 
particles. Remove product residues from the ice condenser 
chamber using a cloth. It is recommended that the lid to the freeze-
dryer or drying chamber is left open when the freeze-dryer is not in 
use so that moisture can evaporate. 
If there is the risk of toxic, radioactive or pathogenic 
contamination, special safety measures must be 
considered and adhered to. 
7.1.7.2.
Cleaning of Accessories
When looking after accessories special safety measures must be 
considered as these are measures to ensure operational safety and 
reliability. 
Chemical reactions as well as stress corrosion cracking 
(combination of changing pressure and chemical reaction) can 
affect or destroy the structure of the metals and plastic parts. Hardly 
detectable cracks on the surface expand and weaken the material 
without visible signs. When visible damage of the surface, a crack, 
