Types of Valves Used in the Automotive Industry 


Different valves and valve layouts are required for different purposes (on/off, control), different fluids (liquid, gas, etc.), different materials, and different pressure and temperature conditions. 

Valves are used in fluid or gaseous handling applications to initiate or stop the flow, regulate or throttle flow, prevent backflow, and relieve and regulate pressure. Automotive industry deals with almost all of these processes. Hence, a variety of valves are used in this industry. 

This article focuses on such valve types and their functions.  

  • Engine Valve

During engine operation, engine valves enable or restrict the movement of fluid or gas to and from the combustion chambers or cylinders. They are mechanical devices that interface with engine components such as rocker arm to open and shut in the correct sequence and timing. They function similarly to other types of valves which block or pass the flow of a substance.

  • A/C Valve (Expansion Valve)

The primary function of an air conditioner expansion valve is to remove pressure from the system’s liquid refrigerant. This allows for expansion before the refrigerant is converted from liquid to vapor inside the evaporator. The valve also controls the refrigerant flow. This process is known as metering. 

At any given time, it can precisely measure the amount of refrigerant required. As a result, this control is required to adjust the A/C.

Inside the valve, a movable rod moves up and down. This enables it to open and close the internal route, allowing or prohibiting refrigerant entry.

  • Brake Valve (Proportioning Valve)

The proportioning valve is an important part of the braking system of a vehicle. The valve usually connects the master cylinder to the rest of the braking system, but it can also be installed separately. This valve is required for proper front-to-rear bias, often known as brake balancing. 

When the brake pedal is pressed, it engages a spring-loaded component that acts when fluid pressure is accumulated.

  • Thermostat Valve

This valve is in charge of keeping the temperature of a vehicle’s engine in check. While many of us are aware of the dangers of an engine overheating, an engine that is too cold will not function effectively. As a result, the thermostat’s function is to maintain a comfortable temperature range between these two extremes. 

The optimal driving temperature is obtained by controlling the coolant flow. As a result, the thermostat valve keeps the engine cool by allowing the coolant to circulate.

  • Fuel System Valves

A fuel system valve is a flow control valve in a vehicle that regulates fluid pressure and liquid flow. These valves are meant to provide gasoline or direct fuel in a double-tank installation in automotive applications. 

Pressure control valves are also used to correct for pressure changes that can impact the stability of gas, steam, water, or chemical processing applications. Automatic control valves can function with hydraulic actuators to open and close the valve in response to pressure and flow variations.

  • Solenoid Valve

Solenoid valves are essential in car wash installations. A solenoid valve, also known as a magnetic valve, is a fluid flow control valve. These valves are electrically controlled. They have a solenoid in the center, which is an electric coil with a moveable ferromagnetic core (plunger). The plunger shuts a small aperture in the rest position. 

On passing the electric current through the coil, a magnetic field is generated. The plunger is pushed higher by the magnetic field, which opens the hole.

  • Exhaust Gas Recirculation (EGR) Valve

Exhaust Gas Recirculation (EGR) is a technology used in modern internal combustion engines to control NOx emissions, which are created as a by-product of the combustion process.

Atmospheric air is primarily a mix of oxygen and nitrogen. When this air comes into contact with fuel and ignites inside the combustion chamber, temperatures rise and NOx emissions are produced.

The key component of the EGR system is the EGR valve, which is generally closed. It joins the exhaust and intake manifolds and is regulated by either a vacuum or an electric step motor incorporated within the manifold. 

The EGR valve’s job is to regulate the flow of recirculated exhaust gas based on the engine’s load.

  • Tire Valve

Tire valves help to keep a car’s tire pressure in check and allow air to enter and exit. The tire valve stem in the wheel is a minor but vital component of a vehicle, especially in terms of safety and tire longevity. A tire valve may be inflated and deflated. It is also a mechanism for testing tire pressure and stops the pumped air from leaking.

There are two varieties of tire valves: one is metal, with a brass main body, and the other is rubber, with a metal rubber main body.

The primary body of a tire valve contains a valve core that functions as a one-way valve. It has the ability to compress air inside the inner tube without allowing free air to escape. The valve core may be screwed in and out using the tire valve cover as a wrench. 

The metal valve nozzle has bridge cushions and compression nuts. It’s utilized to strengthen the inner tube’s bonding strength.

  • Water Valve

Thermal management is the core idea of an automotive water valve. In conjunction with heat control, automotive water valves regulate the in-cabin temperature of a vehicle. They aid in the control and regulation of coolant flow in automobiles, which lowers the heat-up period for fuel and so reduces carbon dioxide emissions. 

Water valves in automobiles remove surplus heat from the engine and maintain the engine operating temperature to the required value. 

Water valves deal with liquids like coolants and need to be of high quality in order to provide rust and error-free operations. Due to its extreme importance, the automotive industry always prefers a reputable and trusted trunnion ball valve manufacturer.  

  • Automatic Transmission (AT) Control Valve

The automatic transmission’s control center is the valve body. It consists of a complex of channels and passageways that feed hydraulic fluid to numerous valves, which subsequently activate the proper clutch pack or band servo for each driving circumstance, allowing the vehicle to smoothly shift into the appropriate gear.

Modern-day automatic transmission sensors in the valve body monitor the speed, throttle position, brake pedal position, and engine load to perform a soft and firm gear shift. The sensors also send vital information to the engine control computer on board.


In this article, we discussed several types of valves used in the automotive industry. Be it nontechnical processes like a car wash or technical processes like vehicle thermal management, valves are used everywhere. 


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