When and why must siphon breaks be installed in a sewage system?

Siphon breaks must be installed in a sewage system whenever components are located below the maximum heeled water line, specifically to prevent backflow. This is crucial because, in a sewage system, the potential for siphoning can create conditions where waste water may flow back into the system instead of moving away from it. Siphoning occurs when there is a sudden pressure drop in the system, allowing liquid waste to be drawn into areas where it should not be. By installing siphon breaks, air is introduced into the system, breaking the siphon effect and ensuring that sewage flows in the intended direction without potential contamination or system failure. This preventive measure helps maintain the integrity of the sewage system and protects against overflow scenarios.

Other situations, like the presence of heaters or considerations for hurricane-prone areas, do not directly pertain to jurisdiction requirements for siphon breaks. While system efficiency can be a broader consideration, the specific requirement focused on preventing backflow in relation to the heeled water line underscores the primary reason for installing siphon breaks.