Understanding the many components that make up a milking vacuum system and recognizing how vacuum function integrates with the entire milking system is key to achieving an optimal milk harvest.

Subtle changes to a milking vacuum system often go unnoticed. But only a small change can create a big issue on teat end health and ideal milking performance. By properly maintaining your vacuum system, you can ensure the efficient harvest of milk while protecting teat integrity.

The vacuum system’s vital role

Machine milking produces a milking vacuum or reduction in air pressure underneath the teat. The pressure differential overcomes the strength of the sphincter muscle surrounding the teat canal, allowing available milk to pass through the teat opening. The vacuum at the teat end needs to remain stable to protect teat health.

The vacuum system is also a vital component of an effective washing system. It can help control entrance and exit gates for some parlors and backflush systems.

Scheduling a system tune-up

A vacuum system consists of the following parts:

  • Vacuum pumps
  • Balance tanks
  • Pump prefilters
  • Motors
  • Anti-reverse check valves
  • Supply and distribution lines
  • Regulators or transducers
  • Variable-speed drives
  • Vacuum gauges

Each component of the vacuum system serves an important function, so it’s essential to schedule complete system checkups on a routine basis. Without a consistent and stable vacuum source, milking and cleaning can be negatively impacted.

Testing of the milking system should take place while cows are milking and with as many available milking units on cows. The National Mastitis Council’s booklet, “Procedures for Evaluating Vacuum Levels and Air Flow in Milking Systems,” outlines the tests evaluating the vacuum system.

Fully trained and competent personnel with the knowledge to interpret the results need to conduct these tests. If the testing reveals issues with vacuum performance or stability, then further testing of the vacuum system using an air flow meter may be necessary.

Also, while it is advisable to check any size of system monthly, testing is usually broken down by dairy size:

  • Larger dairies: On a large dairy, a vacuum pump often runs nonstop. A technician should check the vacuum system monthly for fall-off and overshoot testing. This test not only evaluates the vacuum pump; it also ensures the regulators and transducers are working properly for ideal vacuum levels.

  • Smaller dairies: The vacuum system should be tested every six months. If the test reveals an issue, the vacuum pump will need examination using an air flow meter to ensure it is within the necessary vacuum-producing capacity.

  • All dairies: A monthly inspection of system regulators and vacuum prefilters, belts and other vacuum system components is highly recommended.

The size of your dairy is not the only differentiating factor altering how your system is kept functioning – the type of pump you have matters too:

  • Lobe pump (oil-less): Your technician will most likely flush your system with a cleaning solution, which also helps prevent future residue buildup. He or she will also check the pump for proper crankcase oil levels and grease its bearings if needed.

    Although the lobe pump is called “oil-less” because it does not have oil flowing through the pump itself, it still requires oil to lubricate the gears that turn the lobes.

  • Rotary vane pump (oil-lubricated): Your technician will check for proper oil usage and flush the system with a special flushing oil. This type of pump requires more frequent observation with a weekly check-up, or daily if possible, to ensure oil is flowing properly.

In addition, your technician will check to ensure belts are in good condition and adjust for tension. He or she will also ensure drive couplings are in order.

Until your next check-up

To help determine how well your vacuum system is working between scheduled maintenance dates, check the following:

  • Monitor the pump sound. A louder-than-usual pump may mean there are possible looming issues.

  • For a variable-speed drive, check to see if the pump is running faster or slower than normal.

  • Check rotary vane oil flow and usage through the pump.

  • Monitor cow behavior from milking to milking. Vacuum levels affect cow comfort, and cows may be stepping or kicking at the milking unit, especially at the end of milking, if vacuum levels are off.

  • Check teat condition when the unit detaches. Higher-than-normal vacuum levels can impact teat tissue.

  • Install and maintain an accurate vacuum gauge and monitor it daily to ensure the vacuum level for your system is correct. Vacuum level can greatly influence milkability.

Be sure to inform your technician about overall herd health. Also, let the technician know if there have been changes to milking times, the number of cows in the herd, a liner model or milking system settings. These insights can help your technician determine if your system is working together or needs adjustments.

Delaying a fix or adjustment to your vacuum system can cost more than addressing the issue right away. If issues arise, immediately consult with your equipment supplier to have the issues resolved.

A qualified service technician will provide immense value to your dairy. Work with your equipment specialists and technicians to ensure your vacuum system is working correctly and to schedule regular maintenance.  end mark

PHOTO: Delaying a fix or adjustment to your vacuum system can cost more than immediately addressing the issue. Photo courtesy of GEA.

Mark Walker