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This document specifies the:

— field of application:

— The dimensional, the physicochemical, the design, the hydraulic, the mechanical and the acoustic characteristics of non-controllable backflow preventer with different pressure zones, family C, type A, nominal sizes DN 6 to DN 25, nominal pressure PN 10.

It is applicable to:

— Family C, type A, class “a” for general use: devices of class “a” can be capable of working:

— at any pressure up to 1 MPa (10 bar);

— with any pressure variation up to 1 MPa (10 bar);

— at a supply temperature limit of 65 °C and 90 °C for 1 h;

— Family C, type A, class “b” for specific use: devices of class “b” shall be capable of working:

— at any downstream pressure up to 0,3 MPa (3 bar);

— with any downstream pressure variation up to 0,3 MPa (3 bar); at a supply temperature limit of 65 °C and 90 °C for 1 h;

Class “b” devices can capable of operating: at any downstream pressure up to 300 kPa (3 bar), with any downstream pressure variation up to 300 kPa (3 bar) at a supply temperature limit of 65 °C and 90 °C for 1 h. Class “b” devices with specific hydraulic and non-acoustic requirements and are intended to equip filling devices physically integrated into a single-function (heating) or dual-function (heating and domestic hot water) boiler.

It specifies also:

— test methods and requirements for verifying these characteristics;

— marking;

— presentation and the delivery.