Two-door foot valve

Two-door foot valve also referred to as check valve, it is the fuel tankers when stop to prevent for the suction pipe line liquid reflux must use one of the attachment.Working medium: gasoline, diesel, kerosene, using the environment: - 30℃ ~ + 55℃.
On the valve body and the fuel oil tankers of suction pipe, when the fuel tankers motor starting, form a negative pressure suction tube, make the body side pressure is higher than on the body side pressure;The disc under the influence of the fluctuation pressure difference is raised up, the oil which can enter the tankers suction tube, after the machine stop working, the valve body cavity pressure disappears, and due to the static pressure oil into positive pressure, the disc closed automatically under the effect of positive pressure, the oil from falling.Because the check valve with two sets of the same body and disc, make the performance of the check valve is more reliable.

（source：http://www.kg-machinery.com/news/foot-valve-70.html）

The working principle of globe valve

Globe valve, the valve is one of the most widely used one of the reason it is popular, is due to open and close in the process of friction surface, more durable, opening, manufacturing easy, convenient maintenance, not only suitable for low voltage, and is suitable for high pressure.Globe valve closure principle is, rely on the valve rod pressure, sealing surface and the valve seat valve sealing surface fit closely, prevent medium circulation.Valve in China "three for" regulation, the flow of cut-off valve, shall be applied, so the installation direction.The structure of the cut-off valve length is greater than the gate valve, fluid resistance is big, at the same time run for a long time, seal reliability is not strong.
Globe valve as one of the most important truncated class valves, play an important role in the field of aeronautics and astronautics.As important components of aerospace equipment, cut-off valve to realize the function of medium conveying, globe, such as, the sealing performance directly affects the safe and reliable operation of the space equipment.Study the influence factors of typical cut-off valve sealing characteristics and the influence law, has guiding significance for the structure design of the valve seal, so as to improve the sealing performance and reliability of the valve.

（source：http://www.kg-machinery.com/news/globe-valve.html）

Introduction of check valve

Check valve is used to prevent the reverse flow of oil flow in hydraulic system, or used in pneumatic system to prevent reverse flow of compressed air, flowing fluid is only in the inlet and outlet medium cannot backflow.
Check valve has a straight-through and right Angle type two kinds. Straight-through one-way valve with screw thread connection installed in the pipeline.Right Angle type check valve has a threaded connection, flange connection plate connection and three forms.Hydraulic control one-way valve, also known as block valve or pressure valve, it is the same as the one-way valve, in order to prevent the oil flow.But need to reverse flow of oil flow in hydraulic circuit and available control oil pressure, open the valve, make the oil flow can flow in two direction.Hydraulic control one-way valve used cone valve core, so the sealing performance is good.In requirements when closed oil circuit, this valve is used as oil ChanXiangSuo tight and the holding role.Hydraulic control one-way valve control oil leak means has internal drainage and leaked type two kinds.In the oil flow reverse export without back pressure oil available internal drainage;Otherwise must be leaked type, in order to reduce the oil pressure control.

（source：http://www.kg-machinery.com/news/introduction-of-check-valve.html）

The basic information of foot valve

Foot Valve by valve body, valve cover, valve, such as parts, gasket seal ring and foot valve disc with single and double disc and disc type.Foot Valve after the access to the pipeline, the liquid medium to enter the body from the bonnet direction, the pressure of the liquid on the disc, that allows the medium flows through the valve is opened, when the body within the medium pressure change or disappear when the disc is closed to prevent backflow medium.
Foot Valve, is actually a kind of check valve, to prevent the reverse water role.
Foot Valve according to the material can be divided into plastic foot valve and metal foot valve, also can be divided into ordinary foot valve and backwashing water foot valve.
Foot Valve is mainly used in processing of grout mechanical equipment such as pump, usually foot valve can be installed in the bottom of the suction pump water, to prevent the reverse flow of grout.
At present domestic brand of foot valve quality is generally poor, such as untight seal, the leakage problems, etc., this system is difficult to realize automatic control, each time need to straws in the water, very trouble.
Foot Valve on the valve cover is equipped with multiple inlet, with mesh, in order to reduce clutter inflows, reduce the blocking probability of bottom valve.Although foot valve screen mesh with anti clogging, foot valve is generally applicable clean medium, viscosity and particle through the large medium unfavorable use foot valve.

（source：http://www.kg-machinery.com/news/foot-valve.html）