Size of gas drop vent

Hi all. Hoping you can help me with some gas safety queries. I hv recently finished installing my kitchen unit with smev 9222 in my caddy maxi. I have been reading lots of things about gas installation and have decided to opt for gas locker (to fit 907) and gas drop vent. My query is what size gas drop vent do i need? There is a hole with 10mm diameter hole that is already pre drilled into the floor of my maxi that would sit direcly under my gas locker but most gas drop vents i see are 35mm to 50mm diameter. Is there a reason for this? I.e the bigger the gas cylinder, the bigger the vent needed? Any advice much appreciated. Thanks in advance.

Greetings & Welcome!

10mm is too small. Better to err on the side of safety on this one and go bigger.


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