Abstract: An injector of a type routinely used in an FCC unit for dispersing a feed into a fluidized stream of catalyst particles is given additional versatility and maintainability through the use of internal connections of a low profile type. The injector apparatus has at least one connection that is positioned inside a retaining sleeve and connects the discharge tip of the injector to the piping that extends outside the sleeve and delivers the feed to the injector. The connection can join materials that are not amenable to welding in a space that is too confined for a flange connection. The connection combines the ductile properties of the carbon steel or stainless steel for the feed piping with an abrasion resistant but brittle material that will extend the life of the nozzle tip. Such relatively brittle materials include ceramics. The injector will also routinely incorporate an internal sleeve for separating two different fluids that enter the injector independently and undergo mixing therein.