What are the steps to change the lubricating oil of nitrous oxide compressor?

For nitrous oxide compressor, due to its strong oxidizing and explosive medium and high purity requirements for medical/industrial use, the following steps should be strictly followed for lubricating oil replacement to ensure safety and system cleanliness:

A, safety protection:

1. Wear explosion-proof mask and chemical-resistant gloves (such as butyronitrile), and the operation area is ventilated and far away from fire sources.

2. The system is powered off and warning signs are hung to release the residual pressure of the pipeline (it needs to be released slowly through the explosion-proof pressure relief valve).

Second, the replacement process:

Step 1: Drain old oil and clean the system.

Close the inlet and outlet valves of nitrous oxide compressor, open the oil drain valve at the lowest point of the system, and introduce the old oil into the closed recovery barrel (avoid contact with air).

Inject oil cleaning agent into the crankcase, jog the compressor for 5 minutes (continuous operation is prohibited), and completely discharge the cleaning agent residue.

Purge the oil circuit with dry nitrogen (purity ≥99.99%) for 10 minutes to remove residual liquid and impurities.

Step 2: Vacuum oiling:

1. Connect a vacuum pump to the oil filler, vacuumize to-0.1 MPa and keep the pressure for 30 minutes to confirm that there is no leakage.

2. Inject new oil into the special oil injection tank and suck it through the negative pressure suction system.

It is suggested to monitor the lubricating oil state in real time with online oil sensor to avoid accidental shutdown of nitrous oxide compressor.