Tyre valves: standard or not?

[Xwang]

Hi,
I would like to know if the tyre valves are standard in F1 (from pirelli) or if any team design their valves and in such a case if the technical rules and directives say something about how they must be done.
Thanks,
Xwang

Ps are technical directives available ?

[24000rpm]

is this Xin Wang from Beijing, UCR alumni?

[Xwang]

No, it's only a nickname, sorry