Medicinal Chemists, Organic Chemists, Biochemists, Biologists, Molecular Biologists and other scientists rely upon Vacuum-Driven Devices to concentrate, dry, or filter their materials. If your Vacuum System is not performing optimally, it can slow preparation of research-critical samples by as much as 50%-100%!
This can have a significant impact on time-to-market, or on your research paper productivity. Doesn’t it make sense to be certain that your Vacuum Systems are operating at peak efficiency?
Are You Committed to Improving?
A majority of the researchers must be committed to improving, or management must lead the initiative if the principles learned in the Vacuum System Audit are to have any lasting benefit. Laboratories that ignore the advice generated by such Audits are at risk for more vacuum pump failures, expensive repairs, downtime, lessened productivity and even compromised yield and purity.
Conducting Your Own Vacuum System Audit
Laboratories can benefit from periodic or even continuous monitoring of vacuum system performance. Welch’s inexpensive Digital Vacuum Gauge (1-760 torr) #1520B-01 and #1520K-10 are now available. Digital Millitorr Gauge 1525B-01 and 1525K- 10 are now available. Contact AVAC for details.
Vacuum System Audits typically take the following format:
- A report page template is prepared, with as many copies as there are Systems.The Auditor first measures vacuum achieved within the system. Manifolds should be measured at the terminus, while Rotovaps should be set up with vessels in place and measured at the valve connections near the condensers. Freeze Dryers have their own vacuum gauges, while Vacuum Ovens have an outlet port to connect with. The vacuum gauge can use tubing in the system or use appropriately sized tubing, clamped snugly onto one side of the vacuum gauge.
- When you discover a vacuum pump system that is delivering poor performance, you must determine if the system is at fault, or if the pump’s performance is compromised. This is done by leak checking, a stepwise process where you first measure vacuum levels at the pump inlet, then at each connection, determining where the vacuum loss(es) are. Sometimes the losses come from multiple points. Once you determine the source of poor vacuum, you can rectify by vacuum pump repair or flushing, tightening vacuum tubing or replacing worn, cracked tubing, or cleaning manifold grease.
Cleaning vacuum manifold valves encrusted with chemically-damaged grease is the #1 way to improve Manifold Performance. Carefully tightening or greasing Freeze Dryer manifold valves/ports can help improve vacuum.
Best Practices Must be Followed
The final component for consistently improving Vacuum System performance is, making certain Best Practices are followed. Some of these practices can be managed by facilities or outside service vendors; others remain the responsibility of the researcher:
- Select the correct vacuum pump for the application. The correct technology and correct flow range/vacuum level can
deliver maximum performance with minimal maintenance or repair expense. - Never pump on a cold trap containing thawed, liquid solvents. This will lead to ingestion of oil- damaging chemicals such as Acetonitrile, Acids, and Dichloromethane into the vacuum pump oil. Either use a 3-way valve, inline, between the pump and the cold trap, or keep the cold trap iced without fail, or turn the pump off and re-freeze the trap before restarting the pump.
- Use good or excellent quality oil such as Techni-Clear. Oil should be changed before oil damage progresses too far. That means monthly frequencies for most organic chemistry and many freeze dry applications.
- Select the correct vacuum pump for the application. The correct technology and correct flow range/vacuum level can