Methods and systems for delivering well stimulation materials to a wellbore using a high-pressure delivery manifold are provided. In some embodiments, the methods of the present disclosure include: providing a pressurizable delivery manifold at a well site, wherein the pressurizable delivery manifold is continuously equalized with a piping system; providing a pressurized treatment fluid to the pressurizable delivery manifold; releasing one or more well stimulation materials into the pressurized treatment fluid to create a payload delivery treatment fluid; and injecting the payload delivery treatment fluid into at least a portion of a subterranean formation.