Vacuum suction devices age as time goes on, losing their carrying capacity. Fillers migrate to the surface, other substances from separating agents and coatings reach the surface, and this changes the friction factor of the vacuum suction device. This results in a reduction in carrying capacity and therefore in the supposed safety of the vacuum lifting device. This is independent of the manufacturer of the vacuum suction device.
You cannot tell, by looking at a vacuum suction device, what it is actually still able to carry. Without a load test, it is not possible to evaluate the carrying capacity of a suction cup.
We recommend, as does Wood´s, a company based in the USA, that suction cups should be replaced every two years, unless the load test yields a different result. Also, at that time, all the suction cups should be replaced to ensure that the vacuum lifting device remains able to deliver its rated carrying capacity.
The following videos show you what becomes apparent during a load test.
Just click the link, and the video file will open on any Internet-capable PC.
Why do the suction cups on vacuum lifting beams need to be replaced?
- Example on a Kappel vacuum lifting beam DSZ2/12V
Why is the load test so important in maintenance?
- Example on a Kappel vacuum lifting beam DSZ2/12V
Here you can also view individual tests with suction cups of different ages, and you may then understand why it is so important for your safety and that of the people around you to replace the suction cups from time to time.
Find this on YouTube:
Tensile test with a new 388 suction cup
Find this on YouTube:
Tensile test with a 388 suction cup that is 5 years old
Find this on YouTube:
Tensile test with a 388 suction cup that is 10 years old