In accordance with certain embodiments, a system includes a spray device having a liquid pathway leading to a liquid exit, an air pathway leading to an air exit directed toward a spray region downstream of the liquid exit, and an assembly disposed in the liquid pathway adjacent the liquid exit. The assembly includes a threadless pintle generally fit into a sleeve in a concentric manner without threads. The assembly also includes a generally annular passage between the threadless pintle and the sleeve and a passage coupled with the generally annular passage. The generally annular passage also has a cross-sectional area that alternatingly increases and decreases in a lengthwise direction along the liquid pathway.