What Is a Manual Directional Valve?

Directional valve with two or more flow patterns and two or more oil ports is a direction control valve. It is a valve that allows communication, cutoff and change of hydraulic oil flow, as well as the control of pressure unloading and sequential action. It can be divided into manual directional valve, electromagnetic directional valve, electro-hydraulic directional valve, etc. According to the number of working positions where the valve core stays in the valve body, it can be divided into two-position, three-position and so on; according to the number of oil circuits connected to the valve body, it can be divided into two-way, three-way, four-way and six-way, etc. The ways of operating the valve core movement include manual, mechanical, electric, hydraulic, and electro-hydraulic forms.

Introduction to manual directional valve

Manual directional valve is a direction control valve operated by a manual lever. It works to change the direction (change the direction of liquid flow) and switch (connect or disconnect the liquid flow) in a hydraulic system. Manual directional valve is a kind of unit that can be freely selected. It has two functions. One is like a differential lock on a car transmission. Even if the gears do not mesh, the shift can be completed when the output shaft angle of the engine reaches a certain value. The other is to control the pressure inside the oil passage by changing the direction of the liquid flow, thereby realizing the push, pull and exhaust of the oil cylinder. The manual directional valve has a multi-directional adjustable channel, which can change the direction of fluid flow timely. This kind of changing valve has extensive application in petroleum and chemical production, and is particularly used in the ammonia synthesis gas-making system. In addition, the directional valve can also be made into a valve flap structure, which is mostly used in small flow rate applications. When working, it is only necessary to rotate the handwheel to change the direction of the working fluid through the valve flap.

Working principle of manual directional valve

The manual directional valve is mainly composed of valve body, sealing components, cam, valve stem, handle and valve cover. The valve is driven by the handle, and the valve stem and cam are rotated by the handle. The cam has the function of positioning driving and locking the opening and closing of the sealing components. When the handle is rotated counterclockwise, the two sets of sealing components are closed under the action of the cam, and the two upper channels are respectively communicating with the inlet of the pipeline device. On the contrary, the two upper channels are closed, and the two lower channels are communicating with the inlet of the pipeline device, achieving non-stop switching.

What are the uses of manual directional valve?

Manual directional valve is widely used in hydraulic oil tank systems of construction machinery, coal mining machinery, chemical machinery, light industrial machinery, machine tools and other equipment, which can make the executing elements follow the required direction quickly and accurately, thus realizing arbitrary adjustment of the load.