(commonly referenced as the 50VB series) is a vacuum breaker assembly used to prevent backflow in Delany flush valves like the Flushboy, Presto, and Rex.
Popular Configurations
The VB-50 series is defined by its dimensions, specifically the connection size and the length of the flush tube. Common models include:
50VB-1-9: 1-1/2" top nut x 1-1/2" tailpiece, 9" length.
50VB-1-12: 1-1/2" top nut x 1-1/2" tailpiece, 12" length.
50VB-2-9: 1-1/2" top nut x 1-1/4" tailpiece, 9" length (typically for smaller closets).
50VB-3-9: 1-1/2" top nut x 3/4" tailpiece, 9" length (typically for urinals).