Vacuum Cups — Choosing the Right Size, Shape and Quantity

There is a lot to be said about EXAIR’s E-Vac systems. We have over 10 pages dedicated to this in our catalogue, and many blogs. Click here to see a great blog about selecting the correct E-Vac. Once you have selected the correct E-Vac Generator, we now need to set you up with the right accessories. The connectors and hoses are the easy part – this circles and squares. The magic comes when selecting the proper cup size, shape and quantity. Let’s start by looking at the 3 shapes available; Round, Oval and Bellow.

Round Cups are great for smooth, flat surfaces. They will grip and release quickly, and hold their shape well over extended use. These grip very well on vertical surfaces. For light lifting, use the non-cleated cups, and the cleated cups for heavy lifting. AS you see here we offer a small round and a large round cup.

Oval Cups have the largest surface and therefore provide the most vacuum. You will want to use these on the very heavy items. These are designed to handle flat rigid sheet materials like wood, glass, cardboard boxes and the bulkier items with a flat surface.

Bellow Cups are where we turn when your surface is uneven or textured. The “convolutions” or folds, provide a collapsible area that allows the cup to quickly compress when it reaches uneven surfaces. This cup will take longer to attach and to release due to the larger volume of the cup.

It’s important to note that all EXAIR vacuum cups are vinyl and are ideal for general purpose applications and will wear well. The Durometer rating is A50 and the Temp range is 32°F to 125°F.

From the information above, you should be narrowing down the shape of the cup you need based upon your product. But each of these shapes come in different sizes. Here is a table that shows you all the sizing options of each cup. You will want to keep in mind the size of your product, and the size of these cups. You will most likely need multiple cups to lift your item, so be thinking about how the actual size of the cups will fit evenly spaced on your product. The next step will get us home…

Our last step is to determine exactly how many cups we need to make this a viable and safe application. The first step is to calculate the amount of weight we need to lift. This is determined using a safety factor of 2 for cups positioned horizontally, and a factor of 4 for cups positioned vertically. So if you are moving a 10 lb box, and the cups are on top, you need to account for 20 lbs, and if the cups are on the sides, you need to account for 40lbs. Using the table below, you can see how many pounds that a single vacuum cup can hold, according to the “Hg applied. *** “Hg is based upon the E-Vac you chose earlier ***

As we put all this together it would look something like this. Using the example above, with a box size of 12″x12″x12″ weighing 10 lbs. We will be picking this up with the cups on top of the box, so our total safety weight is 20 pounds, You can see that there are many options that can get this job done. You can use 1,2,3, or even 4 vacuum cups. 1, 2, or 3 E-Vac’s. The key here is to think about safety first, and then consider what issues may arise if something goes wrong. In this scenario, I would consider what is in the box. But if it falls, will it break? If it breaks how much will that cost you?. Also, what happens to production if something tweaks the cups and boxes start piling up. If the penalties are low, I would use 1 cup like a large round (900756) and 1 E-Vac that pulls 10 Hg”. This gives me 34.8 pounds of lift. More than enough. If the box falls and will cost a lot of money, break, slow the process, the 1 cup option is still ok, but I would make this 3 small round cups (900755) and 1 E-Vac that will pull 10 Hg”. This gives me 12.1 pounds of lift on each cup, so if one doesn’t seat correctly, the other 2 (or even one) will still protect me. There are multiple other options as well.

At EXAIR, we have a lot of experience walking through these scenarios and helping make recommendations. Please feel free to call and ask for any of the application engineers for questions or assistance.

Application Engineer

Brian Wages

EXAIR Corporation
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