A vacuum breaker (or siphon breaker) is an attachment commonly placed within the water line, after the inlet valves. This prevents water (containing dirt, chemistry, or both) from the cylinder being siphoned backward toward the inlet valves.
This also prevents contamination should the water system's pressure drop.
In the smaller, fixed cylinder machines, this is accomplished using a peristaltic system using an air gap technique.
In the larger machine where there is no air gap fill device, and CBWs, a Siphon Breaker is used.
These can also be sold with scupper assemblies.
This knowledge article provides part numbers for the siphon breaker as well as the scupper assemblies. Also provided are repair kits where applicable.
a very simple diagram
VALVE SIZES AND USAGE INFORMATION
96M031 / 1.5"VAC BREAKER WATTS LF288AM2
Used primarily for flowmeter assemblies on 76032/76028 CBWs.
 | USED IN SCUPPER SIPHON ASSEMBLY
SA 03 009 |  | REPAIR KIT
96V031K |  |
96M032 / 2"VAC BREAKER WATTS
Used primarily for flowmeter assemblies on 76032/76028 CBWs.
 | NOT USED IN A SIPHON/SCUPPER ASSEMBLY
REPAIR KIT 96V032K |  |
96M033 / 2.5"VAC BREAKER WATTS (used Only in Siphon/Scupper Assembly SA 03 008A)
SA 03 008A used in 42044SP2/SR2 and 42044WP2/WR2, 76032 CBW Flowmeters, Legacy 60" and 72" machines, and 52" Tilt machines
 | Repair Kit 96M033 |
 |
96M034 / 3"VAC BREAKER - WATTS (used Only in Siphon/Scupper Assembly SA 03 007)
SA 03 007 used in 60044SP2, 60044SR2, 60044WP2, 60044WR2, 68036F5N, 68036H5K, 68036M5K, 72044WR2, 72044WP2, 72044SP2, 72046M5K, and Legacy 60", 68", 60", 72", and 52" Dye machines
 | REPAIR KIT
96V033K |  |
