oil seal rotary Vacuum pumps are not intended for use on Amonia or Lithium Bromide (salt water) systems. Both of these systems will cause the pumps to lock up and be rendered inoperable. Use of oil seal rotary pumps on either of these systems will void the warranty.
The reason for this is that if the vacuum is not broken before pumps are shut down the oil in the cover will seek the vacuum still in the cartridge and intake chamber. Then the oil level will drop in the sight glass and give the appearance of a low oil level. Then if the pump is refilled to the oil level line and the pump started, the oil that got sucked back into the cartridge and intake chamber will be kicked back into the cover and now you’ll be over filled and the oil will shoot out the handle (exhaust port).
Keeping the Life of Your Pump includes some troubleshooting tipsCross Reference of Vacuum Measurements
Isolation Valve Leak Test
Principles of Deep Vacuum includes information on measuring evacuation, how to select the right vacuum pump, using a vacuum gauge and evacuation tips
Troubleshooting Digital Superheat/ Subcooling Gauge (SH35N-SH36N)