Dun-Rite Backflow Service

• QUESTION: What is backflow?
• ANSWER: Backflow is the undesirable reversal of flow of nonpotable water or other substances through a cross-connection and into the piping of a public water system or consumer's potable water system.
• A backflow prevention assembly is used to protect water supplies from contamination or pollution.

  In water supply systems, water is normally maintained at a significant pressure to enable water to flow from the tap, shower etc. When pressure fails or is reduced as may happen if a water main bursts, pipes freeze or there is unexpectedly high demand on the water system, the pressure in the pipe may be reduced and may allow contaminated water from the ground, from storage of from other sources to be drawn into the system. To prevent such an occurrence, many water purveyors require there to be a mechanical backflow prevention assembly between the delivery point of mains water and water users. In this way the backflow prevention assembly protects the potable water system from contamination hazards.

• QUESTION: Why do backflow preventers have to be tested periodically?
• ANSWER: Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested with properly calibrated gauge equipment.

   

Contact your local, and state government for specific rules and regulations regarding backflow policies and procedures.