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Upgrade nowPrinciples of Backflow
Read through the material below, then test your understanding.
Module Lessons
Cold Water
Incoming Mains: Communication vs. Supply Pipes
Installation Depths and Building Entry
Direct Cold Water Systems
Indirect Cold Water Systems
Siting and Installing Storage Cisterns
Float-Operated Valves and Overflows
Principles of Backflow
Terminal Fittings and Taps
Non-Mechanical Backflow Prevention (Air Gaps)
Water Treatment and Distribution
Mechanical Backflow Prevention Valves
Commissioning: Testing and Flushing
Lesson Overview
Backflow is the unwanted reversal of water flow that can draw contaminated fluids into wholesome drinking water supplies. Understanding the mechanics of backpressure, back-siphonage, and the five fluid categories is essential for protecting public health under the Water Regulations.
Learning Objectives
Explain the principles and causes of backflow, distinguishing between backpressure and back-siphonage.
Identify the five UK fluid categories and the specific contamination risks associated with each.
Describe the hierarchy of backflow protection including whole-site, zoned, and point-of-use installations.
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