Principle and structure of check valve in refrigeration system

One-way valve with one-way through, reverse cut-off capacity.

One-way valve, also known as check valve, it is often in the air-conditioning system, and electronic expansion valve (capillary) parallel, control the positive and negative flow of refrigerant, refrigerant can only flow in a specified direction.

The one-way valve comprises a nylon valve needle, a valve seat, a limit ring and a housing.

Generally in the one-way valve with the outer surface of the arrow marked refrigerant flow.Special care should be taken when installing substitutions, not inverting them.

According to the different internal structure, one-way valve can be divided into ball valve and needle valve two kinds.

1、Needle valves

The needle-shaped check valve is mainly composed of nylon valve needle, valve seat, limit ring and housing.

When the refrigerant flows in the positive direction, the nylon valve needle is opened and pushed to the limit ring by the refrigerant flow pressure, the one-way valve is connected.

When the refrigerant reverse flow, nylon valve needle by the one-way valve pressure difference at both ends of the role of the tight pressure on the valve seat, one-way valve is in the cut-off state.

2. Ball valve

When the refrigerant flows forward, the pressure on side A is higher than that on side B, the steel ball moves to the left, and the refrigerant flows from A to B.

When the refrigerant flow reversed, b-side pressure is higher than A-side pressure, steel ball to the right move, blocking the refrigerant flow pipeline, then the one-way valve will be in the cut-off state.