20 Pa.C.S. § 765: Service of citation.

A citation to obtain jurisdiction of a person may be served by an adult person, or by the sheriff of the county wherein the citation issued, or by deputization of the sheriff of the county where the service may be had in any county of the Commonwealth, in the same manner as a writ of summons in an action of assumpsit. When no other time is specially fixed by the orphans' court division, the order awarding the citation shall be void unless the citation is issued within six months.