Execution standards

Manufacturing and acceptance standards shall be in accordance with GB13927-92

The flange connection standard is in accordance with GB/T9113 GB4216

Product Introduction

This valve, also known as an anti fouling isolation valve, is installed at the connection between drinking water pipelines and non drinking water pipelines (such as fire protection and swimming pools), at the outlet section where the water supply pipeline may be flooded, and on various pipelines that require no medium backflow. It is used to prevent backflow fluid from contaminating the water supply network, ensuring clean water sources and hygienic drinking water.

Working principle

This valve is operated by the inlet watercheck valveThe outlet check valve is combined with a butterfly check valve to implement three-level isolation for the reflux medium. Under normal circumstances, the medium flows forward inside the valve. When the medium returns, if the inlet check valve fails due to various factors, the returning medium will continue to be obstructed by the intermediate butterfly check valve. If both the first and second seals fail, the outlet check valve can also prevent the returning medium, which is called a three-stage partition. This valve is safe and reliable, and plays a very important role in preventing backflow pollution.

This valve can be divided into Type I and Type II due to its different structures. Type I is a common type with a simple structure, belonging to a three-level partition structure; Type II is a safety type with a secondary partition structure, consisting of an inlet partition and an outlet partition. The only difference is that it has a drainage device in the middle. Its function is to open the drainage device under hydraulic power when the inlet pressure is lower than the valve chamber pressure or lower than the outlet pressure, preventing the siphon effect from introducing unclean media into the water supply network.