What does vacuum pump maintenance and gambling have in common?
As Kenny Roger’s sang…”If you’re gonna play the game, boy You gotta learn to play it right… Every gambler knows that the secret to surviving is knowing what to throw away and knowing what to keep”
Keeping up with industrial pump maintenance and being alert for poor vacuum performance will help you stay ahead of the game and not gamble its life away. Read on for easy steps for troubleshooting the performance of your vacuum system.
No pump will deliver good results on a poor vacuum system, and the best pump in the world won’t work if you have a leaky chamber. Let’s keep it simple and first focus on the easiest place and most likely suspect of a poor vacuum…the pump. Is it time to hold them or fold them? The biggest tell-tale sign that your pump could be in trouble is when the ultimate base pressure diminishes.
Factory specification for base pressure for stokes type piston pumps is typically 10 millitorr or less. If you are pulling under 20 millitorr you are usually fine. However, when the vacuum pump doesn’t meet your application specification (described in your standard operating procedures) for ultimate base pressure then it may be time for rebuilding or vacuum pump repair. The first maintenance step is to change the oil before you go any further and recheck the base pressure. If you get improvement then change the oil again…you may see further improvement.
How do you document the base pressure of your vacuum pump? Check out this blog on baselining your vacuum pump to assess its performance over time. Using our method to easily catalog base pressure tests enables quicker troubleshooting in the future.
What are the top 3 reasons a rotary piston pump is rebuilt or replaced?
- 25% are seized due to poor maintenance
- 50% get abnormally loud due to a bearing problem
- 25% are rebuilt according to preventatice maintenance schedules (3 years is a common rebuild interval)
Most of the time when a pump needs to be rebuilt, it is because the shaft seals leak. Often there are actual grooves in the shaft which causes the shaft seals to leak.
Always keep a good pump activity record that keeps track of: oil changes, work done on pump, and changes or additions to the system. This will be a great value when checking for leaks or assessing poor vacuum.
Isolate and Repair leaks in your vacuum system
After you have verified that your vacuum pump can pull down to the necessary vacuum level on its own, then it is time to investigate the system.
- A leak rate will help localize a vacuum leak. Such a test is easily made by successively isolating each section of the system, evacuating, and then taking successive readings over a period of time. Our Bullseye Precision Gauge® (also available with Bluetooth) can be a great asset in completing this maintenance item quickly and accurately
- A vacuum leak detector will also speed up the process of the locating leaks. There is expense and skill required to use a vacuum leak detector, so if you go this route choose wisely.
Repair Small Leaks
- Use sealing compound to repair small leaks or to close pores
- When replacing plug type valves (if used) use Pipe Sealer to help seal them. Gate, Ball or Butterfly type high vacuum valves are preferred for high vacuum service.
In Summary: If your system isn’t getting to the necessary vacuum level, investigate the pump first, then move on to rest of the vacuum system. So you know when to hold onto your pump or when it is time fold and move on!
Find out how you can take the emailed data from the Bullseye Precision Gauge® and create a graph to illustrate a pumpdown curve for troublshooting and baselining vacuum pumps.