Backflow preventer

Abstract

The invention discloses a backflow preventer, comprising a valve body, the valve body is opened with overhaul holes, the overhaul holes are connected with a valve cover, the valve bodies at the two sides of the overhaul holes are internally provided with demountable check valve components, and a water escape valve is arranged between the two check valve components. The backflow preventer of the invention adopts arranging two demountable check components at two ends of a single valve body or a combined valve body, as well as arranging overhaul holes and valve covers at upper part of the valve bodies, thus realizing on-line overhaul, namely, taking out the check valve components for replacement or repairing conveniently after opening the valve covers.

Description

technical field [0001] The invention belongs to a pipe network control valve, in particular to a backflow preventer. Background technique [0002] In order to prevent the backflow of sewage from the pipe guide in the water pipe network, two check valves connected in series are generally required to form a backflow preventer. The backflow preventer is mainly used in direct drinking water systems and occasions that have strict requirements on the water quality of the pipeline system. The head loss of the current backflow preventer is generally 0.7kg / cm 2 , the water head loss is relatively large, and the water supply pressure must be increased during normal water supply, which consumes a lot of energy. And this structure is more complicated. At the same time, the check of the current pipeline check valve is realized by the force of the spring. When the valve is closed, the spring force is the smallest, and when the valve is fully open, the spring force is the largest, so w...

AI Technical Summary

Problems solved by technology

When the valve is closed, the spring force is the smallest, and when the valve is fully open, the spring force is the largest, so when the flow rate of the system decreases, the valve is often in a half-open state under the action of the spring force; when the valve is checked, the valve is closed The spring force is the smallest when the valve is closed, so no effective check can be formed when the valve is closed; the spring pressure is the largest when the valve is fully open, which seriously affects the system efficiency

However, due to the limitation of the structure, all kinds of backflow preventers can not be repaired online. During maintenance, the backflow preventer needs to be removed from the pipeline, and then the check valve device should be replaced or repaired.

This is a lot of work and takes a long time to repair

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