The design intent of any pipeline or plumbing system is for its contents to flow in a specific direction. Backflow is the unwanted reversal of flow of liquid, solids, or gas from its intended direction into the potable water supply, often resulting in contamination. Periodic inspection and testing of backflow prevention devices is strictly regulated by local, state and federal agencies to ensure these devices are working properly. PJM Mechanical Contractors, Inc. is fully certified to perform backflow preventer testing and can assist customers with all BFP maintenance and repair needs.
Backflow is usually caused by one of two main causes. Back siphonage occurs when there is a partial vacuum, or negative pressure, in a water supply system, causing it to draw from a contaminated source into the potable water supply. Back pressure results when the pressure of a non-potable system exceeds the positive pressure in the water distribution lines and forces contaminated water into the system. Common sources of back pressure include boilers, heat exchangers, water distribution pumps, and fire suppression systems.
A backflow preventer is a device or method that prevents backflow and reduces the risk of contamination. The most basic backflow prevention method is a vertical air gap that acts as a barrier or eliminates a cross connection, but air gaps are not always practical and can easily be bypassed. Mechanical backflow devices are more effective, providing a physical barrier to backflow. The four most common types are reduced pressure assemblies, double check valve assemblies, pressure-type vacuum breakers, and atmospheric vacuum breakers.
At minimum, BFP testing should be performed annually, and may be required as frequently as every three months, depending on the facility. To find out more about backflow preventers or to schedule inspection or service, please contact PJM at 609-921-1394.
PJM Mechanical Contractors, Inc. is a multi-faceted mechanical contractor providing construction and installation, service and maintenance, and design/build services in a comprehensive range of mechanical disciplines that include HVAC, plumbing, controls, refrigeration, custom metal fabrication, piping, fire protection, and backflow preventer testing. PJM primarily serves clients in pharmaceuticals, manufacturing, healthcare, institutional, and other various commercial and industrial sectors.