Block check valve for cutting off or recovering medium return of oil path of oil supply system

Abstract

The invention discloses a block check valve for cutting off or recovering medium return of an oil path of an oil supply system and provides a low-resistance backflow preventer which is reliable in sealing performance, durable, capable of closing a valve stably, and small in pressure fluctuation. According to the technical scheme, a valve rod is connected with a check valve seat located under a check valve body through a valve deck with an arched section and a reset spring arranged in the valve deck; in the return state, a flow medium entering a joint valve body tube downwards pushes the valvedeck, the reset spring is driven to reversely push the check valve body to the initial position, the sealing surface of the check valve body is attached to a flange sealing ring in linear contact withthe end direction of the check valve body, and thus, the flow medium is prevented from flowing back to an inlet of the valve from an outlet; and in this way, the flow direction of the flow medium ischanged, cut-off or recovery of the flow medium between an upstream valve cavity and a downstream cavity of the valve rod is controlled, and flow control for blockage or zero-pressure blockage is achieved. By adoption of the block check valve, the defects that in the prior art, a check valve body is large in size, high in weight, difficult to assemble and large in resistance are overcome.

Description

technical field [0001] The invention relates to a device for cutting off or connecting the medium, controlling the flow, changing the flow, changing the flow direction of the medium, and preventing the backflow of the medium, especially a low-resistance backflow preventer used in the low-pressure oil circuit of the fuel oil supply system of a diesel engine. Background technique [0002] Usually, backflow preventers are used in urban buildings and community water supply systems, fire water system, municipal water supply pipe road System, etc., to prevent the phenomenon of unclean water flowing back into the main network, the double channel drain valve. In the prior art, the low-resistance backflow preventer is a device consisting of a main valve of a double-stage check device and an external drain; its function is to prevent the medium in the pipeline from backflowing under any working conditions, so as to avoid backflow purpose of pollution. The main valve of this doub...

AI Technical Summary

Problems solved by technology

The disadvantage of this low-resistance backflow preventer composed of two check valves at the front and rear and an automatic drain in the middle is that the structure is relatively complicated and the volume is large, so it is not suitable for use in the low-pressure oil circuit of the diesel fuel oil supply system.

However, after the seals of the two check valves are destroyed at the same time, the check function is lost, and its safety and reliability are relatively poor.

The low-resistance check valves in the prior art usually cannot meet the low-resistance reverse flow used in the low-pressure oil circuit of the diesel fuel oil supply system.

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