tierced in a circle(?)

A tierce into 3 equal sized "pie slices" as per correspondence here:

_I also have another question on my mind. For a worldbuilding effort I have going on, I'm imagining a culture whose heraldry would frequently be presented in divisions of three. Specifically, I would hope to be able to produce a circular shield divided radially in three 120-degree pie slices. It seems "per pall" is the usual way to achieve this in blazon, but it always seems to set the top slice at 90 degrees. Is there any normal blazon language that specifies three 120-degree sections? (Or failing that, is there a way to hack it in DrawShield blazon?)_

(Can't use variant edges but straight edges are very easy)

Also need to think of a proper heraldic sounding term for it...