Introduction to the Function and Characteristic of One-way Valve

One-way sealing valve seals can be sealed in the forward installation, but can not be sealed in the reverse installation.
Two-way sealing is not required.
There are two-way seals and one-way seals in the structure of ball valves. Generally, there is no flow direction requirement for two-way seals and one-way seals have flow direction requirement.
Manual ball valves have no direction, but if the control valve is directional.

The function of one-way valve in hydraulic system is as follows:
(1) If the one-way valve is installed at the outlet of the pump, it can prevent the sudden increase of pressure in the system from damaging the pump, that is to say, it plays a check role.
(2) Parallel connection of one-way valve with throttle valve or decompression valve can form positive slow, reverse fast or positive deceleration and reverse free flow circuit of actuator.
(3) If the one-way valve and the pressure valve are connected in series, the adjustment pressure can be gradually increased and the reaction of pressure can be prevented.
(4) For liquid-controlled one-way valves, one-way valves can be opened by controlling the oil path to achieve the purpose of reverse flow of oil. The main function of one-way valves is to control the movement of oil in only one direction. One-way valves should meet the following performance requirements:
(1) When the oil flows in one direction, the resistance is smaller, that is to say, the pressure loss is smaller.
(2) The sealing of the contact between the spool and the valve seat is good, and there should be no leakage at all. When the oil flows back from the reverse direction, it should not pass through at all.
(3) The action of one-way valve should be quick and sensitive, and there should be no impact and noise when working.

General ball valves do not indicate the direction, can be installed at will. In theory, the ball valve has no direction, but in order to prevent the leakage between the valve body and the valve cover from being too large, the ball valve body is usually connected with the direction of the tank or material. Some ball valves have directionality and are generally marked on the ball valves, which fail to achieve good sealing.
There are two kinds of ball valves, one-way sealed ball valve and two-way sealed ball valve. The former has directionality, and the latter has no directionality if installed in reverse. There are two-way seals and one-way seals in structure: two-way seals generally have no flow direction requirement, one-way seals have flow direction requirement.
Manual ball valves have no direction, but control valves have direction. V-type ball valves and eccentric hemispherical valves are directional, generally marking medium flow direction in the valve body. Floating ball valves and fixed ball valves are bidirectional, while eccentric hemisphere valves, V-shaped ball valves and lifting stem track ball valves are unidirectional.
Ball valves are divided into O-type ball valves and V-type ball valves. O-type ball valve adopts floating structure, ball core is precision castings, hard chromium plating treatment on the surface, valve seat adopts reinforced PTFE material, runner mouth and pipeline diameter are the same, flow capacity is great, flow resistance is very small, no leakage when closing, generally used as switch valve, especially for high viscosity, containing fibers, granular media; V-type ball valve adopts fixed structure, with V-type notch on the ball core, which can realize proportional adjustment, and the flow characteristics are approximately equal percentage. The medium flows to the valve body.
As a user, O-type ball valves are generally used for switching, basically two-way sealing, so there is no directional requirement; V-type ball valves are used for control, generally one-way sealing, with directional requirements.
In actual use, the characteristics of each product may be different, just depending on whether there is flow direction indication on the valve body, if not, it is bidirectional seal, no installation direction requirements. If so, it is necessary to install the instruction installation to achieve good sealing effect.

How to choose and buy one-way valves to be assured

One-way valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent medium backflow, also known as check valve, one-way valve, counterflow valve, and back pressure valve. One-way valve belongs to an automatic valve. Its main function is to prevent medium backflow, reverse pump and drive motor, and release of container medium. One-way valves can also be used to supply pipelines for auxiliary systems where pressure may rise above system pressure. One-way valves can be divided into swing one-way valves (rotating according to the center of gravity) and lifting one-way valves (moving along the axis). The function of one-way valve is to allow medium to flow in only one direction and to prevent reverse flow. Usually, the valve operates automatically, and the disc opens under the action of a fluid pressure flowing in one direction. When the fluid flows in the opposite direction, the disc acts on the seat by the fluid pressure and the self-coincidence disc of the disc, thus cutting off the flow.