How Does Float Valve Work?

How Does a Float Valve Work?

Float valves are essential components in various systems, including well systems, bucket pumps, and toilet tanks. The mechanism of a float valve operates on a straightforward principle. It employs a floating ball or bowl that adjusts its position according to the water level in a tank or container. When the water reaches a specific level, the float triggers a valve or switch to open or close.

Yaxing Valve products are renowned for their quality and are exported globally across numerous industries. Our commitment is to offer high-value products that meet the needs of our customers, fostering a collaborative future ahead.

Comparing Float Valves and Float Switches

If you inspect a toilet tank, you will notice an air-filled balloon attached to a rod linked to the fill valve. When the tank is drained, the float descends with the water level, prompting the rod to open the fill valve, allowing water to flow in. As the water rises, the float ascends, ultimately closing the valve and halting the water flow. This scenario illustrates the classic function of a float valve.

On the other hand, float switches operate under a similar principle; however, they activate a switch to control a pump rather than a valve. These pumps may be employed to fill reservoirs in well systems or to empty wells in discharge systems. In sump systems, the float switch triggers the pump when water levels drop and does not deactivate once the water level rises.

Understanding Ball Valve Control

To grasp how a float valve functions, you need not seek the mechanism in your bathroom toilet. Lift the tank lid, flush, and hold the float in place to see how it alters the water level. By slightly lowering the float, observe the initial trickle of water that increases as the float descends deeper into the tank—opposite to its behavior when the tank fills.

The float rod connects to a spring valve that remains closed unless the lever's force from the falling float opens it. The water level can be modified by adjusting the arm's length or the positioning of the ball.

Many downhole systems utilize a float valve, such as a ball valve or float switch, to maintain reservoir levels. When water levels dip below a predetermined threshold, the float lever activates a pump in the well, which operates until the water flow hits the pump’s cutoff point.

Components of a Float Valve

While the visible components include the floating ball and lever, the functional part of the float valve resides within the valve body. If we could observe an X-ray view, we would reveal either a slide valve or a diaphragm valve mechanism.

The valve consists of a horizontally sliding cylinder. In its closed position, the float lever chamber presses against the water inlet, blocking water flow. When the float lowers, it releases the piston, allowing water to flow freely.

In contrast, a diaphragm valve operates similarly but utilizes a rubber membrane instead of the sliding cylinder. Typically, these valves feature a screw for adjusting the diaphragm's tension, which can increase or decrease the valve's sensitivity to the float rod's movement. Tighter adjustments move the diaphragm closer to the water inlet, leading to earlier closure of the valve.

Float Valves – Function and Features

Float valves are primarily used where the safeguarding of drinking water against backsiphonage is crucial, conforming to DIN EN standards. Float valves are indispensable in various applications, notably in toilet cisterns where they refill post-use, and also in systems such as rainwater harvesting and car washes.

The operation of float valves is uncomplicated: they rely solely on buoyancy rather than electronic controls. As the water level falls, the float connected by a lever triggers a mechanism that opens the valve, allowing for inflow until the water level is restored.

For further reading on different types of valves, including float valves, please visit our page on industrial valves types.