Backflow Preventer (UNI)

The backflow preventer

A backflow preventer is a device which is intended to prevent possible contamination of potable water by backflow in the case of a temporary water distribution facility depressurisation.

Backflow preventer operates by disconnecting the hydraulic circuits: such disconnection is a break in a hydraulic circuit creating an atmospheric area between two elements, one carrying or containing potable water (upstream) and another carrying or containing another fluid (downstream).

The hydraulic disconnection occurs even in case of backflow preventer failure.

Reference standards

  • UNI EN 1717: "Protection against pollution of potable water in water installations and general requirements of devices to prevent pollution by back flow."
    This European Standard deals with the devices to be used to prevent the pollution of water intended for human consumption inside premises and the general requirements for the protection devices intended to avoid the water pollution by backflow.
  • UNI EN 12729: "Devices to prevent pollution by back flow of potable water - Controllable back flow preventer with reduced pressure zone - Family B - Type A."
    This European Standard specifies the field of application, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical and the acoustic characteristics of controllable back flow preventer with reduced pressure zone Family B Type A.

The third party surveillance: auditing and testing

As Product Certification Body, SIET carries out both the initial audit and then the yearly surveillance audit in conformity with the requirements of the applicable certification scheme. Such activities are carried out at the manufacturer site.

Furthermore both the initial verification and the next yearly surveillance include the performance of the all tests required by the reference standards at the SIET laboratory.

Only companies that have demonstrated compliance with the requirements of the Certification Scheme and whose products have passed the initial tests and surveillance are authorized to implement and maintain on their backflows the "UNI" marking. In these conditions SIET, as Conformity Assessment Body, issues a certificate of compliance, with no expiring date.

The names of all companies holding certificates of compliance shall be published in the section "Certificate List" of the present web site. Suppliers, installers and consumers have free access to this list.

To know all the details of both the general regulations and the Certification Scheme and the prices please go to the section "downloads of contractual documents".

Visit UNI website. Download product list.

Request for Quotation

To request for a quote regarding certification services please refer to this section.