Is there a universal size for piping nozzles?

I have no idea what you’re talking about, even after looking at the site to which you refer! Could you enlighten me? What the heck ARE “piping nozzles,” and what are they for??

“the number series used to identify piping tubes is not standardised as many people assume – there are at least 5 such series in operation, so please check the number, design and description carefully before ordering. ”

Source

piping nozzles fit on the end of piping bags, they allow you to control the amount of icing that comes out. They come in different sizes for different jobs, if you want to ice lettering on a cake you need a thin nozzle if you want to make flowers’stars then there is a special nozzle for that too!

http://www.cake-decorating.co.uk/techniques-tips/beginners-guide-piping-icing/
this looks an interesting website that has lots of icing tips.

American sizes are different to English sizes I think, and it does depend on make, what may be one size for one company may have another name with another company.

When I see my mum in a few days I’ll ask her a she decorates cakes :)

Thank you for that explanation. I never knew icing could be so complicated! : D