How Elevation Affects Vacuum Cup Performance

by Jessica Smith

Key Points High elevations can reduce lifting capacity. If your location exceeds 5000 feet [1524 m], check the Specifications page of your instructions manual for the maximum operating elevation. When lifting in high elevations, be extra careful to make sure the vacuum pads and load material's surfaces are clean. Never lift a load if the indicators do not show adequate vacuum.

Now that you are an expert on the effects of temperature on hand-held vacuum cups and below-the-hook vacuum lifters, it is time to move to the next section of our four-part series - elevation. Like temperature, elevation has a universal effect on vacuum cups and vacuum lifters; however, the way elevation affects your specific product depends on many different factors, including the weight and surface characteristics of the load. Whether you are using a 3-inch [8 cm] vacuum cup or a below-the-hook vacuum lifter with many pads on it, the naked truth is that the effectiveness of your product decreases as elevation increases. When air is removed from the inside of a vacuum pad, a vacuum is created. The weight of the air above the pad - also known as atmospheric pressure - is what holds the pad in place. As elevation increases there is less air above you; therefore, the atmospheric pressure decreases. The less air there is, the less difference there is in air pressure inside and outside the vacuum pad. It is this difference in air pressure which is measured as the "vacuum level" of vacuum cups and vacuum lifters. As a result, the higher you climb above sea level, the lower your capacity. Up to about 6500 ft. [1981.2 m], atmospheric pressure decreases by approximately 1% for every 330 ft. [100.6 m] of elevation.

Vacuum Lifters

Since vacuum is more difficult to achieve at higher elevations, it is harder for the vacuum pumps on below-the-hook vacuum lifters to obtain and sustain adequate vacuum to hold and maneuver loads. Under certain conditions, this could cause the load to be released unintentionally, damaging the material or injuring the operator. If you are using a below-the-hook vacuum lifter above its recommended elevation, the vacuum level will remain in the red "no lift" zone on the vacuum gauge, no matter how long the pump runs. If a DC backup system is installed, it may also run continuously. Refer to the Specifications page of your instructions manual to ensure you are below the maximum operating elevation.

Hand-Held Vacuum Cups

If you are using a hand-held vacuum cup at a higher elevation than is recommended, the red-line vacuum indicator will continue to appear regardless of the number of times the plunger is compressed.

Additional Considerations

Other factors such as load and surface conditions must also be considered before operating your vacuum products at higher elevations. If the surface of the load you want to lift is rough or porous, this may be the reason your vacuum cup or lifter does not work at higher elevations. On the other hand, if you have a load that is considerably lighter than the maximum load weight, this may make lifting it at higher elevations possible. Whatever the case, you need to be aware of the condition of your load surface and your vacuum cup or lifter, especially when considering their use at higher elevations. If your location exceeds 5000 feet [1524 m], first check the Specifications page of your instructions manual for the operating elevation, then if necessary, contact your Technical Sales Representative for further consultation.

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Jessica Smith was a Staff Writer on the Wood's Powr-Grip Marketing team. She was responsible for editing, researching and writing articles, instructions, publications and newsletters.