Call Now To Order. FlowLine is a custom architectural linear slot diffuser system designed to integrate supply and return air openings into interior commercial buildings. Stocked Sizes. Choose an option, 96" Long x 1 1" slot. Flow Cross for Flowbar Diffusers. FBMC. FL-TZ. Mitered Corner for Flowbar Diffusers. Clear. Nailor Linear Diffusers and Bar Grilles are engineered and designed to satisfy high performance applications that require an aesthetically pleasing design. Nailor Linear Diffusers and Bar Grilles are engineered and designed to satisfy high performance applications that require an aesthetically pleasing design. FlowLine is a custom architectural linear slot diffuser system designed to integrate supply and return air openings into interior commercial buildings. The Flowline™ FLV Series continuous slot diffuser is designed for both ceiling and high sidewall applications and provides total air pattern control flexibility. © Advanced Air (UK). . Categories: Air Distribution, Linear Diffusers SKU. Flowline™ diffuser assuring proper dimensional layouts for simple diffuser installation. The Flowline™ FLV Series continuous slot diffuser is designed for. FBP Architectural Linear Diffuser, Aluminum, 1" Slot. Architectural Slot. Flowline High Capacity Linear Slot Diffuser · Model 35SST VAV · External Louvre A member of the Nailor Industries International group. Flowline Diffuser Vertical.