BFM® Australia Blog

How do you calculate the Installation Gap with vertical movement?

Written by Matthew Bailey | Jun 17, 2026 12:32:44 AM

When an application has vertical movement, like on a tumbler screener, some additional factors need to be considered when calculating the Installation Gap (IG) before installing your BFM® spigots.

You must ensure that you have enough connector length for the peak of the movement and that the IG takes into account both this connector length and the actual position your machine stops in (which is how it will be positioned when you physically weld the spigots in place).

So how do you allow for this vertical movement when calculating the Installation Gap?

We asked our Technical Lead, Matthew Bailey, to explain how to work this out in this quick video.



In this video, Matthew covers the following:

  • measuring the maximum vertical movement during operation

  • identifying where your equipment will be stopped during spigot installation

  • how to adjust the installation gap from the IG calculator appropriately

  • why it's so important to allow for vertical movement when calculating your IG

If you've got more questions around the installation of your BFM® fitting system, download our 'Installation Guide Book' here or get in touch with us - we're here to help!