Your Ultimate Guide To Float Valves

Water supply systems require valves to control water flow and reduce leaks and spills. Valves can be used to initiate or halt water flow, regulate the rate and volume of water flow, or restrict the flow to a certain direction.

Tank levels can be controlled with the help of ballcocks, also known as float valves. A float valve consists of a valve body and a hollow ball of varying sizes and shapes that are attached to the valve by a lever or arm. 

The valve is opened or closed mechanically based on the float’s position concerning the tank, which it does by floating on, near, or beneath the surface of the fluid. All-mechanical methods for regulating the water level can be made using float valves. Please continue reading to the end for details on float valves.

Floating Ball Valve Design

Let’s describe the main parts of a ball valve before we go into the specifics of the floating ball valve design. 

The housing for the valve mechanism is called the “valve body.” Steel, iron, brass, bronze, and even PVC which is often used by medical device component manufacturers, are all common materials for float valves.

A float valve consists of a spherical ball that pivots around a central shaft or stem and allows fluid to pass through it. The interior is a bore or port. A valve packing is a flexible seal around the valve stem that keeps media inside the valve.

A seal between the valve body and the ball is formed by a disc called the seat. The shaft that holds the ball and links it to a control lever or actuator on the outside.

An actuator is an external device that turns the valve’s stem. An actuator can be anything from a simple lever to a complex gear driven by a motor (an electric actuator) or a pneumatic/hydraulic system.


A certain type of ball valve is sometimes called a “floating ball valve.” Distinct from the float valves discussed above, these are entirely different.

Float valves can be found in several different designs, with no single style being the industry standard. Other types of valves tend to have “standardized” layouts. 

In light of this, it is recommended that those responsible for specifying float valves or floating ball valve vs trunnion must thoroughly research the products of various manufacturers. It is important to locate the valves or valve systems that are most suited to the specifics of their tank systems.

To What End Do Floating Ball Valves Work?

The stem, or shaft, on top of a floating ball valve, rotates the ball across a 90-degree arc to open and close the valve (a quarter turn). The media flow is either allowed to continue or is stopped as the ball spins within the valve body, covering or uncovering the port. 

As the ball spins on its axis, the pressure of the flow presses it against its downstream seat, forming a tight seal. This is made possible by the loose connection between the stem and the ball. 

Floating ball valves can lose some of their sealing ability in low-pressure applications when the seat has been worn down a bit. This is because the media pressure may not be high enough to push the ball firmly against the downstream seat, preventing any leaks just like quality ptfe seals

While worn seats can be a problem, downstream pressure is usually enough to keep a seal for a long time.

Different Float Valves and How They Work

You can choose from two distinct designs for the float valves.

  1. Manually Controlled Float Valve
  2. Automated Float Control Valves

The tank’s liquid level causes the float valve to rise with direct float control.

A float valve arm unit controls the opening and closing of the main valve in this straightforward setup.

Manually Controlled Float Valves

When the liquid level in the tank rises, the float moves up to prevent the pilot valve from opening. The main control valve developed liquid in the upper chamber.

The diaphragm in the upper chamber applies pressure to the main valve, closing it.

When the water level drops, the float drops, opening the float valve’s pilot line. The main valve has been opened, and water can now enter the storage vessel.

Depending on the situation, the main valve can be situated either close to or far from the float valve.

The Best Way To Choose A Float Valve

The following constraints on the process are used to decide which float valve to use:

  • Intense pressure
  • Metal floats and PVC floats have different optimal temperatures; thus, choosing the right float material is important.
  • Typically used with a liquid that is not corrosive, such as water


There is zero necessity for oversight or management. Regulation of the level is performed automatically during operation.

When the water reaches the proper height, it will automatically shut off to prevent flooding.

Because no electricity is used, it is also cost-effective. Useful for monitoring tank levels in locations without access to electricity.


Because of the high pressure in pipes, float valves cannot be used. They are only for use in low to medium-process pressure environments.

As floats are so easily broken, it’s possible that they may be swapped out.


Clean and service your level controls and float valves regularly. Particularly relevant are valves in infrequently used systems, such as those found in sprinkler installations.

If a liquid contains a chemical that might quickly solidify into deposits, it is crucial to clean it thoroughly (such as iron, lime, suspended solids, etc). Rapid wear can be caused by sand and abrasive particles transported along the fluid. 


Float Valves, which open and close in response to changes in liquid level, can be used to regulate the amount of water in the tank. The valve is under the mechanical control of a float. 

Float valves are a common component of commercial and industrial refrigeration systems. Large refrigeration systems often employ float valves as throttling components. 

These controls keep tanks and cisterns from filling to the point of overflowing. These valves are adaptable to various pressure levels and can be used in various applications. The gadget serves as a throttle in massive commercial and industrial cooling systems.