Pneumatic Valves and Manifolds

What Are Pneumatic Valves?

A pneumatic valve is a type of valve packed down with air. They can control the rate and the amount of air, as well as the air pressure as it makes its way through a pneumatic system. These systems utilize the force of the compressed air as a means to transmit power. They are a good way to transmit power to many different parts of a machine since it needs just a single source of air. The valves can determine where the air and thus the power go in the machine.

The pneumatic valves and systems are a part of a host of applications including diesel engines and pressure power tools. Some types of systems and devices might even use more than one type of pneumatic valve. One of the most important types of pneumatic valves is the directional control valve, which can control or prohibit the flow of air.

Several different basic types of valve designs are available – poppet, diaphragm poppet, spoppet and spool.

The poppet valves make use of a rubber-molded poppet that goes around the stem of the valve. It moves along the bore and creates a seal. This is a popular design because it works with more than just compressed air. The diaphragm poppet uses outer webbing that helps to guide the poppet to its seat without needing to have a sliding seal. They are durable and have low leak rates.

The spoppet design is a combination of a poppet and spool valve design, which helps to bridge the gap between these two designs, ultimately making it more useful for different types of applications. Spool valves are a cost effective option and they are available in two-way, three-way, and four-way configurations. They can be balanced or unbalanced based on specific requirements for the system. However, spool valves are only useful for certain types of systems, and they are generally acceptable only for systems that use air.

Most of the time, the pneumatic valves are found in low-pressure applications for machinery. The valves and their components are lightweight because they utilize plastic and aluminum, and this makes them much easier to work with for those smaller applications. However, it is possible to create the valves, as well as the base and all of the other components, from a heavier duty metal in the event they need to be used for heavy-duty applications.

 

How Does a Pneumatic Valve Work?

Air trips the valve and causes it to open or to close. Different sorts of valves work in slightly different ways. The two-way valves turn the air on and off for a specific application. Most of the time, these are found in shop air systems, motors, supply air for tools, and similar systems. In some circumstances, they can be used as vent valves.

A three-way valve will work in a similar fashion to the two-way valves. However, they actually have a third port that is used for exhausting the downstream air. These types of valves are generally available in two different configurations – normally open and normally closed. They can control single acting cylinders or spring return cylinders. They are also useful for piloting other types of air-operated valves.

Operation of a four-way valve utilizes two of the three-way valve functions operating at the same time. One of these is normally open and one is normally closed. They have two outlet ports that alternate from pressurized to exhaust. Most of the time, the four-way valves are useful for operating double acting air cylinders, as well as bi-directional air motors most often found in air circuitry.

Another type of pneumatic valve is the spring-offset valve. This refers to how the airflow direction is switched. In open valves, the airflow is enabled, and in closed valves, the airflow is prohibited. Actuators will move the valve spool into different areas to achieve the open or closed position.

 

What Are Pneumatic Manual Control Valves?

Many pneumatic valves are in-line applications, and that means they do not require any additional manual operation to function. However, with some types of valves, there does need to be actual physical control over the valves in order to manipulate them to perform the right function at the right time.

These manual control valves come in a variety of styles for a host of different applications. They have four-way two position manual valves, as well as three-position valves that are operable by hand with joystick control and toggle controls. They also have manual valves operable by foot pedals. They are available in a wide range of different configurations for all manner of systems.

 

What Are Blanking Plates for Pneumatic Control Valves?

A blanking plate is a piece of metal that closes off and helps to secure and seal the area around the valve. They cover the valves as a means of protecting them from outside elements, such as moisture or dust, which could affect the control and the quality of the valves. These are available in different sizes and styles based on the use and the type of valve.

 

What Types of Bases Exist for Pneumatic Control Valves

Pneumatic control valves are available with a variety of different types of bases on which they are mounted. They come in various sizes based on the type of valve, the purpose, and the configuration. The external pipe work of the valve is what attaches to the base.

 

Manifold Bases, Sub Bases, and End Bases

The manifold bases are large blocks on top of which the valves will fit and attach. Many different types of valves can use this configuration, and some bases might have several valves on them, including valves for direction, for relief, one-way valves, flow dividers, and more. Sub bases and end bases have the same basic functions, but they are for different areas of the valve. The use of the various bases depends upon the application.

The bases, as well as most of the other parts of the valve, are usually aluminum or plastic, which helps to keep their weight down, which is very important when dealing with machinery that should stay light.

 

What Are Pneumatic Solenoid/Pilot-Operated Control Valves?

Solenoid usually refers to coils used in order to create a magnetic field when the coil is wrapped around a magnetic core, and in the case of valves, it refers to the mechanisms used in order to convert energy into motion. They will generally control the flow of air or sometimes water with a switch. If there is a current applied to the solenoid, it is active, and this will open the valve. If it is inactive, and there is no current, then the valve will remain closed. When one opens or closes this valve, manually or through an actuator, the term is called changing state.

In some cases, the solenoid has a pneumatic actuator that will change the position of the valve. The compressed air that pushes through the valve will actually trip it and cause it to open or to close. Solenoid valves are part of the pneumatic process, and often pneumatic valves and solenoid valves are used at the same time and in the same process in combination. The pneumatic valve is generally smaller, and it will activate the solenoid valve. Another term for the pneumatic solenoid valve is compressed air pilot valve.

The pilot operated control valves offer a number of benefits. They can provide higher system operating pressure, and they are good for environments that may have a substantial amount of vibration. Some of the most common types of applications for these valves include washing machines, dishwashers, irrigation sprinkler systems, and even in paintball guns. The paintball guns use the compressed air as a means to power their weapon and fire the paintballs.

 

What Are Pneumatic Solenoid Coil Connectors?

The connectors on solenoid coils are often just lead wires that stem out from the coil. However, today, many manufacturers that make valves will offer DIN connecters for the coils. These do not have lead wires, as most connectors do and instead have prongs. In these coils, the coil is the male connection, and the plug that connects to it is the female connector. Using these types of coil connectors offers a number of different benefits. First, they are faster and easier to use. They also have better insulation, and many of them are highly resistant to water.

Several different types of these plugs are available with different pin spacing. They include 18mm, 11mm, 10mm, 9.4mm, and 8mm. It is possible to find these available as shells only, with the coil added later. They are also available fully created and ready to go. Some will also have LED indicators, which can be a handy addition. The light on the LED can let the user know whether the coil has power.

The tape-wrapped coils are most likely to have lead wire connectors, whereas the encapsulated coils will have the DIN connectors. The one to choose depends on the usage and the situation. Some will naturally be better options for some environments than the other will.

 

What Are Pneumatic Solenoid Coils for Pneumatic Control Valves?

The solenoid coils convert electrical energy into linear motion. As mentioned, the coil is wrapped around a magnetic core. The coil is often copper, but it could also be aluminum. When the current flows through the coil, it creates a magnetic field. The core is also called the plunger and as the current flows through the coil, the plunger becomes an electromagnet, and it moves further into the coil. This actually opens the body of the pneumatic control valve.

The construction of the valve will usually be either encapsulated coils that are in a mold, or a tape-wrapped coil. They serve the same basic function. However, the tape-wrapped coils are often better for light-duty environments. They have a thin layer of insulating tape around them. The molded coils are generally stronger and are better for heavy-duty uses. They also have a greater resistance to moisture.

The valve coils are available for use with AC and DC. The coils can work with a number of different levels of voltage. However, the ones that are most common for DC are 6-volt, 12-volt, and 24 volt. The ones that are most common for AC include 24-volt 120-volt, and 220/240 volt. The lower powered voltages are safer, and they are generally the best option for hobbyists who are just learning. The heavy-duty applications will use the AC voltages as they can offer more power, which is necessary for good performance in the larger machinery.

It is important to note that the power supply must always be able to meet the minimum requirements of the coils in order for them to work properly.

 

What Is Pneumatic Valve Mounting Equipment?

Adding pneumatic valves to equipment requires the right type of mount, which can vary based on the size of the valve, the equipment it is going into, and the usage. The cost for the mounting equipment varies based on the material and the size. They are usually high quality plastic or aluminum. As with all of the other components that go into creating the valves, the mounting equipment is available from a number of different manufacturers including Siemens, SMC Pneumatics, and Parker Hannifin Pneumatics.

 

What Are Pneumatic Valve Repair and Maintenance Kits?

While most of the pneumatic valves are high quality and can last for a long time, there may come a point where they need to have a repair so they can continue working. It is also a good idea to maintain the valves so that they do not have a failure that could cause a machine to stop working and reduce productivity. Instead of buying all new valves and replacing them, many companies find it cost effective to make use of pneumatic valve repair and maintenance kits instead. These kits come with the elements necessary to keep the valves in good working condition.