VIDEO: How does a petrol nozzle know when to shut off? October 27, 2016 · by Ruan Schoeman · in Equipment, Videos. · How does a petrol nozzle know when to shut off? Share this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to email a link to a friend (Opens in new window)Click to print (Opens in new window)Click to share on WhatsApp (Opens in new window)