The following is an excerpt from the article "7 Questions to Ask Before Buying a Vacuum Pump" by Greg Marciniak, product marketing manager for the Industrial Vacuum Division at Atlas Copco. The full version can be read online
Vacuum pumps are used for a wide range of applications in a variety of industries, but not all vacuum pumps are created equal. Before selecting a vacuum pump, take a look at the following questions. Knowing the answers will not only help you streamline your purchasing timeline, it will also ensure you get the right vacuum pump for your application.
- What’s the required operating pressure?
Understanding the required operating pressure for your application is vital. Operators almost universally know this. But when purchasing new or replacement equipment, some conflate required operating pressure with ultimate pressure. Operating pressure is the pressure required for a certain process, while ultimate pressure is the deepest operating pressure a given pump can produce. If a machine specification states the ultimate pressure as 0.01 mbar, this does not necessarily mean this is the normal operating requirement for a process.
- What is the required flow?
Flow can be expressed in a few different ways. Some of the more common terms are SCFM and ACFM. Understanding the difference between the two is critical. SCFM, or standard cubic feet per minute, is an expression of flow at a specific set of conditions. SCFM assumes that the temperature is 60°F, the pressure is 14.7 psia and the relative humidity is zero percent. ACFM, or actual cubic feet per minute, is the flow at actual conditions. Mixing these terms up can result in greatly undersized or oversized equipment.
- Is contamination a risk?
Because vacuum pumps pull the process toward the system rather than pushing air away, it’s vital you discuss how wet or dry your application is with any vacuum pump provider, as each poses certain risks to a vacuum pump system. Wet or humid applications are extremely common, especially in the food packaging industry. With some processes, there’s a chance the moisture will be pulled back into the pump. That information helps vacuum pump providers specify the correct technology and protect the vacuum pump from contamination, adverse reactions or premature failure.
Dry applications also pose potential issues. Some operators use vacuum pumps to move bulk material for concrete, plastic pellets, etc., which can ultimately end up in the pump without adequate filtration. Regardless of how wet or dry your process is, knowing how the vacuum pump will be used will ensure that the correct protection is in front of the pump.
If contamination does occur, it can cause any number of unfavorable effects. The oil used for lubrication, cooling and sealing can be damaged, causing the pump to malfunction or operate on a less-than-efficient level. Contamination can also harm the pump itself, leading to more required maintenance and a shorter lifespan.
What are the four additional questions you should ask before purchasing a vacuum pump? Find out when you read the full article on Blower and Vacuum Best Practices’ website.