Fan Cooled Vacuum Pumps

Possible Causes

• Air Leaks: Inspect all hose connections, manways and sight glasses to make sure they’re sealed and aren’t leaking.
• Collapsed Hoses: Hoses on various parts of your vacuum system have an internal lining or diaphragm which can collapse shut under vacuum.
• Faulty or Stuck Backup Valve: Check the backup valve function by looking in through the diverter – you want to make sure it’s not stuck open or closed.
• Faulty, Broken or Stuck Primary or Secondary Shutoff: The float balls and cages in your shutoffs can become damaged or stuck.
• Worn Vanes: Over time, the vanes can wear down and lose their ability to create a proper seal against the housing.
• Dirty Filters: Clogged or dirty filters can restrict airflow.

Solutions

• Check for Leaks: Tighten all hose connections and replace any damaged seals.
• Check Hose: Put the pump in pressure and see if pressure comes out of the hoses – if pressure comes out, but not vacuum- you have a collapsed hose.
• Check Primary and/or Secondary Shutoff: If the ball is stuck into the seat during operation, no vacuum will be pulled out of the tank. These float ball devices work similarly to the float balls in a shop vac – as the tank fills up it floats the ball close enough to the hose connection to suck the ball into it cutting off the airflow.
• Replace Vanes: If the vanes are worn, replace them with new ones according to the manufacturer’s guidelines.
• Clean or Replace Filters: Regularly clean or replace filters to ensure proper airflow.
• Check Vacuum Tank Components: Inspect primary shutoffs (float balls), secondary shutoffs, hoses, connections, manways, sight glasses, and any other penetration into the tank that could reduce the quality of the vacuum.

Possible Causes

• Inadequate Lubrication: Rotary vane pumps require adequate lubrication to function properly.
• Faulty or Broken Oil Pump: Vacuum pump needs constant lubrication to run, if the oil pump is not functioning properly the pump will overheat very quickly or if the wrong type of oil is used.
• Blocked Airflow: Blocked intake or exhaust ports can cause the pump to overheat. Cooling fins of casing plugged with dirt, clogged oil line or clogged filter or muffler.
• Excessive Load: Operating the pump at a higher load than recommended can lead to overheating. RPM too high or runs for too long WITHOUT air passing inside the pump.

Solutions

• Check Lubrication: Ensure that the pump is adequately lubricated according to the manufacturer’s recommendations.
• Check Oil Pump: Remove oil cover and check if the oil pump is pumping oil into the lines. Use recommended oil types.
• Clear Blockages: Inspect and clear any blockages in the intake and exhaust ports.
• Operate Within Limits: Make sure the pump is not subjected to loads beyond its designed capacity – like RPM, environmental conditions, dirty or clogged fan or fins.

Possible Causes

• Mechanical Jamming: Broken vanes, debris, or other items present in the pump can stop the rotor.
• Vane Sticking: Vanes can stick if not properly lubricated or if they are damaged.
• ‘Hydro-Lock’: If you pull fluid into the pump, it will most likely ‘hydro-lock’ by breaking a vane or an end cap as it tries to compress the fluid.
• Pump frozen up due to winter conditions.

Solutions

• Clear Jams: Check your shutoffs and filters daily to ensure there’s no risk of debris or fluid getting into the pump. Inspect internal components for wear and replace any worn parts as necessary.
• Lubricate Vanes: Ensure the vanes are properly lubricated and replace them if they are damaged.
• Check Shutoffs: Check your shutoffs to make sure no fluid is getting by.
• Oil Consumption Rate: Ensure oil consumption rate is the same as in regular operation, which is 16-17 hours of pumping per gallon of oil.