
Low-Resistance Backflow Preventer LHS743X is a backflow prevention device specifically designed for water supply systems, featuring a combination of a two-way check valve and an external drain. It controls the flow of the medium through a safe pressure difference ΔP≥0.005MPa, preventing water quality backflow contamination. Its core advantages include:
Core Features
Air Break: When the main valve is closed, the drain valve automatically opens to form an air break, blocking the reverse flow path of the medium.
Automatic Drainage: When the pressure difference is insufficient (ΔP ≤ 0.005 MPa), the drain valve releases the accumulated water in the intermediate chamber to restore a safe pressure difference.
Low-friction design: Head loss ≤ 0.03 MPa, suitable for scenarios with sudden drop in water supply pressure.
Technical Specifications
Nominal Pipe Size: DN40 - DN600 (some models support DN1200)
Nominal Pressure: PN1.0 - PN2.5 (equivalent to 1.0 - 2.5 MPa)
Main Material: Carbon Steel, Stainless Steel
Connection Type: Flange Connection
Application Scenario
For scenarios requiring anti-reverse pollution protection in municipal water supply, fire protection systems, reclaimed water treatment, and industrial pipelines.

































