Change Oil in Your Freeze Dryer's Vacuum Pump

Oil Quality is Essential

The pump that comes with your freeze dryer relies on high-quality oil to create negative pressure within the food chamber. Maintaining your oil regularly is crucial as it affects the performance of the freeze drying process. You have the option to either filter and reuse the existing oil or replace it with new oil.

When to Change the Oil

To ensure optimal performance, oil changes should be made periodically:

• Standard Pump: Filter or change the oil after 3-5 cycles or if it appears murky in the sight glass.
• Industrial Pump: Change the oil every 30 batches or after 1000 hours of drying. Additionally, drain the oil in the demister after every batch and monitor the pump oil level. 

Note: If the oil appears yellow but remains clear, it is still usable. Oil color can change due to pigments from the food, which does not affect its effectiveness. However, if water from the food mixes with the oil and causes it to look murky, then it is necessary to change/filter the oil.

Oil Options

You have two options for maintaining your pump's oil:

1. Replacing with new Oil: Opt for new oil from recommended brands such as JB Black Gold Vacuum Pump Oil, Robinair High Vacuum Pump Oil, or any vacuum pump oil with a viscosity of ISO 40-60.

   Diaryland Vacuum Pump Oil is recommended exclusively for standard oil pumps for its corrosion protection, which helps keep the inside of the pump clean. This eliminates the need to ever open up the standard pump for internal cleaning.

2. Filtering Used Oil: If the oil level is low after filtering, top it up with new oil.

Steps to Change the Oil:

1. Set Up the Oil Filter

   • Set up the oil filter using the plastic pitcher at the bottom, followed by the steel mesh, a paper filter, and multiple layers of tissue paper.
   

2. Draining the Oil

   • For standard pumps, open the ball valve to drain the oil into the filter system.
   • For the industrial pump, which lacks a ball valve for drainage, use the provided hex key to gently open the drain screw, allowing the oil to flow into the filter system. It’s advisable to place kitchen towels or absorbent paper underneath the pump during this process. This precaution helps catch any oil that might miss the collection container, preventing messes. Without this step, oil can accumulate at the bottom of the pump, which could be mistaken for a leak and is challenging to clean up later.
          

3. Filtering the Oil

   • Wait for the oil to filter through into the plastic pitcher.

4. Refilling the Pump

   • Once filtered, reuse the oil to refill the pump.
   • Check the sight glass to confirm the oil reaches the proper level. If not, top up with new oil.