Обратен вентил низводно за спречување на повратен проток од серија 575.

https://www.caleffi.com/mk-mk/%D0%BE%D0%B1%D1%80%D0%B0%D1%82%D0%B5%D0%BD-%D0%B2%D0%B5%D0%BD%D1%82%D0%B8%D0%BB-%D0%BD%D0%B8%D0%B7%D0%B2%D0%BE%D0%B4%D0%BD%D0%BE-%D0%B7%D0%B0-%D1%81%D0%BF%D1%80%D0%B5%D1%87%D1%83%D0%B2%D0%B0%D1%9A%D0%B5-%D0%BD%D0%B0-%D0%BF%D0%BE%D0%B2%D1%80%D0%B0%D1%82%D0%B5%D0%BD-%D0%BF%D1%80%D0%BE%D1%82%D0%BE%D0%BA-%D0%BE%D0%B4-%D1%81%D0%B5%D1%80%D0%B8%D1%98%D0%B0-575-caleffi-59627