Angle non-return check valve for boiler and storage cylinder connection to the pipework G 1 union nut x G 1 ½ pump flange, 47 x 40 mm, with Optiflex fill and drain
![574 Controllable, reduced pressure zone backflow preventer. 1 1/2" - 2". BA type | Caleffi International 574 Controllable, reduced pressure zone backflow preventer. 1 1/2" - 2". BA type | Caleffi International](https://www.caleffi.com/sites/default/files/styles/product_photo/public/file/574900.jpg?itok=ge049EuP)
574 Controllable, reduced pressure zone backflow preventer. 1 1/2" - 2". BA type | Caleffi International
![574151A - Caleffi 574151A - 3/4" Threaded 574 Brass RPZ Backflow Preventer & AutoFill Combo w/ Gauge (Lead Free) 574151A - Caleffi 574151A - 3/4" Threaded 574 Brass RPZ Backflow Preventer & AutoFill Combo w/ Gauge (Lead Free)](https://d3501hjdis3g5w.cloudfront.net/images/products/zoom/574151a-1.jpg)