The LHS743X Low-Resistance Backflow Preventer is a hydraulic control device used for interconnections between urban water supply networks and various user networks. Its primary function is to prevent backflow contamination, ensuring water quality safety. Below are its core features and technical specifications:

Core Features

Air Break and Automatic Drainage: Upon closure of the main valve, the drain valve automatically activates, creating an air break or zero-pressure break, effectively blocking backflow contamination.

Low water loss: Head loss less than 0.04 meters of water column (about 0.03 MPa) at a flow rate of 2 m/s, significant energy saving.

‌Anti-pollution isolation: Suitable for cross-connections between potable water systems and non-potable water systems such as greywater and firewater, to prevent water contamination.‌

Technical Specifications

Pipe Diameter Range: DN50-DN400

Nominal Pressure: 1.0-2.5 MPa

‌Material: Optional ductile iron or stainless steel‌

‌Installation Method: Supports horizontal or vertical installation‌

Applicable Scenarios

Town water supply network connection to user's pipeline

Potable water and reclaimed water, fire protection water, and other non-homogeneous water system crossover points

Non-impingement equipment installation package

Structural Features

The design employs a two-stage check valve with a main valve and an external drainage unit. The main valve is made of a monolithic structure with an isometric flow channel. The sealing force of the valve disc relies on the pressure difference between the inlet and outlet to achieve self-sealing, ensuring a compact structure and flexible installation.