Series 580 backflow preventer with multi-function geometry
WHAT IS A BACKFLOW PREVENTER FOR?
The backflow preventer is a protective device that is installed between the main water system and the utility circuits in water distribution systems, and creates a safety zone to prevent the water in the two circuits from coming into contact. It also protects the main water system from downstream pressure, back siphoning and backflow.
WHY INSTALL A BACKFLOW PREVENTER?
Potable water from the mains supply may be subject to pollution caused mainly by the contaminated fluids flowing back from plumbing installations connected directly to the mains supply. Backflow can be attributed to a variation in the pressure difference that causes a consequent inversion of the normal direction of flow at certain point of the installation. This phenomenon, known as “backflow”, can cause significant problems and occurs when:
- the pressure in the main water system is less than that in the downstream circuit (back siphoning). This can happen, for example, due to a break in the pipework of the main water system and the consequent maintenance work, or when significant quantities of water are drawn by other utilities connected upstream, such as fire-fighting systems.
- the pressure in the plumbing circuit receiving the supply rises (counter pressure) due, for example, to water being pumped from a well
WHAT DO THE STANDARDS SAY?
In Europe, the applicable standard is EN 1717:2000 on prevention of pollution by backflow, which classifies the water in systems according to its level of hazardousness to human health and the corresponding most suitable backflow prevention devices:
- Category 1: Water to be used for human consumption coming directly from a potable water distribution system.
- Category 2: Fluid presenting no human health hazard, as per 1, the quality of which can have undergone a change in taste, odour, colour or temperature.
- Category 3: Fluid representing some human health hazard due to the presence of one or more harmful substances.
- Category 4: Fluid presenting a human health hazard due to the presence of one or more “toxic” or “very toxic” substances or one or more radioactive, mutagenic or carcinogenic substances.
- Category 5: Fluid presenting a human health hazard due to the presence of microbiological or viral elements.
BA water backflow preventers can be used to protect against the risk of pollution from backflow for types of water up to category 4. Air gap separation must be used for category 5 types of water.
For more details, there is a dedicated guide on this topic.
WHY INSTALL A WATER BACKFLOW PREVENTER WITH MULTI-FUNCTION GEOMETRY?
The strong point of the backflow preventer with multi-function geometry is its versatility. It can provide three possible configurations with a single body: in-line (for horizontal and vertical pipes) and on a tap for temporary applications both with and without an inlet shut-off valve. The version for in-line installation (on a horizontal or vertical pipe) can be easily converted into a version for special applications, and vice versa, thanks to the interchangeability of the upstream union with the elbow union and the shut-off valve upstream. Thanks to the compactness and versatility of its body, the 580 series backflow preventer is also suitable for protecting systems with mediums below category 4, so that only one device needs to be kept in stock.
Watch the video.
DOES THE BACKFLOW PREVENTER REQUIRE MAINTENANCE?
Certainly. The backflow preventer is a health and safety device that requires periodic inspection. According to EN 806-5 regulation, BA type backflow preventers should be inspected once every six months and undergo routine maintenance once a year. We would like to highlight the fact that the first sign of poor operation, usually caused by foreign bodies (sand or other impurities), is a permanent leak from the drain valve: this leak, however, does not compromise safety, but means that the device and the upstream strainer built into the union must be disassembled for cleaning. However, disassembly and maintenance have been simplified by the product conformation, which has components that are easy to check and replace without having to disassemble the valve body from the pipe.
Caution! It is prohibited to bypass the backflow preventer, so it is good practice to procure a spare device in the case of critical installations. The "Quick checking method" item in the technical brochure at the link below provides a troubleshooting diagram for the most common problems. We recommend reading it.