HS41X-A type filter anti fouling isolation valve (pipeline backflow preventer)Detailed product description：

The HS41X-A filter anti fouling block valve consists of two separated check valves and a hydraulic transmission to the drain valve. The first check valve body is equipped with a filter screen. Due to the local head loss of the check valve, the pressure in the middle chamber is always lower than the pressure at the inlet. This pressure difference drives the drain valve to be in a closed state, and the pipeline is supplying water normally. When the pressure is abnormal (i.e. the outlet pressure is higher than the central chamber), even if both check valves cannot seal in reverse, the safety drain valve can automatically open to release the backflow water and form an air partition to ensure the hygiene and safety of the upstream water supply.

Debugging steps
Before formally installing and cultivating anti fouling isolation valves, all pipelines should be thoroughly flushed to eliminate other unrelated troubles. After installation, during initial use, in order to prevent damage to the O-ring displacement and internal components during violent movements, it is necessary to follow the following steps: close the outlet gate valve, slowly open the inlet gate valve, let water slowly fill the valve cavity, open each test ball valve to remove air from the valve cavity, and after the valve cavity is filled with water, slowly open the outlet gate valve to let water fill the entire pipeline.

Performance and Application
The structure of the backflow preventer product has the characteristics of rationality, easy use, strong sealing performance, durability, and beautiful appearance. Widely used in power, metallurgy, petroleum, chemical, gas, urban construction, papermaking, textile, medicine, food, shipbuilding, water supply and drainage, energy, drilling and other sectors.
1. The regular type can be installed vertically or horizontally
2. Safe horizontal installation, with a clean environment and sufficient maintenance space. The outlet of the safety drain or (air barrier) should be at least 300mm above the ground and not submerged by water or debris
3. Drainage facilities should be installed in the installation area
4. A gate valve (butterfly valve) and a rubber flexible joint (or expansion joint) should be installed in front of the valve, and a gate valve (butterfly valve) should be installed behind the valve. When the water quality is poor, a filter should be installed in front of the valve

HS41X-A type filter anti fouling isolation valve (pipeline backflow preventer) main component materials

Part Name	Material
Valve body and valve cover	Cast iron, carbon steel, stainless steel
valve disc	Carbon steel, stainless steel, nitrile rubber
valve stem	Aluminum bronze, chromium stainless steel
Diaphragm	Nitrile rubber
Diaphragm pressure plate	Carbon steel, stainless steel
spring	stainless steel