A wide range of regulated fittings connect different elements within spray guns. Air supply lines and hoses commonly join via national pipe thread (NPT) or national pipe straight (NPS) threaded parts. Depending on the application, fittings may have quick-disconnect features. Connectors designed for inlets and outlets are available in straight and tapered forms. Most spray gun fittings are 1/4, 3/8, or 1/2 inches in diameter, although larger sizes exist for other connections, such as a 3/4-inch garden hose.
An efficient hose fitting reflects an insignificant drop in pressure. At 25 scfm (standard cubic feet per minute), a high-flow connector might lose 1.2 psi from a 50 psi inlet. This minor loss is far more favorable than the 40 psi potentially lost from an A-style connector. In high pressure low volume (HVLP) guns, a high flow ball and ring lock type provides a secure fitting while maintaining desirable flow levels.