What is a Directional Control Valve?

What is a Directional Control Valve?

The directional control valve or spool valve can be seen in pneumatic or hydraulic systems. Several well-known control valves are available in the industry, such as Globe Valves.

This article discusses different types of control valves known as Directional Control Valves or DCVs. Spool valves and solenoid valves are also common names for them.

Watch this video or read this article to find out how directional control valves work and how their symbols should be read and interpreted.

Directional Control Valves vs. Modulating Control Valves

Most control valves are known for their throttling capabilities and adjustability. DCVs, however, control the flow of liquid within a pipe by controlling the “direction”.

Flow control systems using pneumatic and hydraulic directional valves are both common.

There are two types of directional control valves: pneumatic and hydraulic. Hydraulic directional control valves are sometimes referred to as spool valves.

Directional Control Valve Application Example

Our example is based on a pneumatic valve system since we are learning about the basics of DCVs in this article and there is not much difference in their working principles and symbols. The good news is that if you learn one of them, you can easily learn the other as well.

First, let’s look at a simple pneumatic circuit. An air compressor supplies the compressed air that powers this pneumatic system. This slide gate valve is opened and closed by the directional control valve using its actuator, which is a double-acting cylinder, that directs compressed air in two directions.

In one direction, the cylinder expands and closes the slide gate valve to block the material coming out of the silo, while in the other, the cylinder retracts. Slide gate valves are therefore normally closed valves.

Directional Control Valve Components

The first part of the valve is its body or housing, which contains the paths through which air flows. An integral part of the valve’s body is a series of holes, known as ports.

Within the housing, there’s a moving part that directs air toward different valve ports and blocks others. Spools are commonly used to describe this moving part. An electric solenoid is responsible for moving the spool within the housing.

How Directional Control Valve Works (5/2 Solenoid Valve)

As the DCV spool is in its neutral or rest position, when the solenoid is energized by a PLC card command, the coil will push the spool and squeeze the spring on the other side. Therefore, the piston of the cylinder retracts and moves to the right.

A PLC’s command will remain on the solenoid as long as the piston remains at its last position and the spool stays stationary.

Once the PLC removes the command, the spring will return the spool to its original position and the air path will change.

In this way, the air behind the piston will be expelled into the atmosphere through the exhaust port of the valve. The next step is to learn how to name and read the graphic symbols associated with the directional control valves.

Why do They Call it a 5/2 Directional Control Valve?

This valve is known as a 5 by 2 solenoid valve or a 5 by 2 directional control valve. What is the meaning of 5 by 2?

The first digit represents the number of ports on the valve. A second digit indicates the number of states the spool can be in.

How to Read a Directional Control Valve Symbol

Sometimes it can be challenging to read and interpret directional control valve symbols. As an example, let’s look at the symbol for a pneumatic directional control valve with 5/2 openings. For each state, some arrows illustrate the paths air can take through them.

5 by 2 DCV has 5 parts, and these are the ISO designation of the ports, which is more common practice. There may be an alternative designation of Directional Control Valves by alphabets in which;

  • The P stands for the “power” or “pressure” that comes from the air source.
  • The exhaust ports are marked Ea and Eb.
  • The A and B ports are the actuator’s output and input ports.
  • On the schematic of the Directional Control Valve, there are signs for electric solenoids and spring returns.

In our circuit, the square beside the spring symbol is active when the valve is at rest.

The other square becomes active when the solenoid energizes and the spool moves. It is a rule of thumb for any directional control valve schematic that the square next to the solenoid sign becomes active when the solenoid is energized.

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How Does a Pneumatic Valve Work?

How Does a Pneumatic Valve Work?

We rely upon equipment ANd elective stuff for a regular reason. What we don’t perceive is anyway every one of them works. have you ever for any reason considered what a gas valve is? moreover, what type of equipment is gas. On the off likelihood that you simply lack the haziest arrangement, you’re getting to find.

What is a gas valve? this probably won’t be A request that is methodically uncovered, in any case, it’s something anyway A request that should be answered. A gas pneumatic valve is one among the sections that are in charge of prevailing the major problem, rate, and life of air that is gone through a gas structure. A gas system is utilized in equipment and elective stuff to move and pack the air that is in charge of running the motor. The gas system is found in hardware that is imperative in unambiguous fields like mining.

Maybe the most pieces of medications that use the gas structure could be conveyed. These derrick systems square measure yet utilized these days inside the mining industry and square measure fundamental. Derrick structures essentially work to lessen the existence of major problems acclimated move the variable, causing it to feel lighter than whatever it very is. These structures square measure used to convey the significant masses up from the mines and to the surface, the derrick equipment is like that of a pulley block. The gas system wasn’t regularly utilized in raised structures and their square measure 2 varying sorts that were customary before the gas system:

Physically: stomach muscle there was without a doubt no permission to drive and in this manner the best because of making the derrick system work was with irksome work. This encased using the 2 animals and others to help the bounty. These crane systems square measure in charge of fostering a portion of the old designs that square measure still around these days.

Electric: this crane structure utilized the ability to figure. Using power helped with making the work go stacks quicker, and it was direct as squeezing a catch and looking because the machine bound up the irksome work.

Then, at that point, the gas system was given. This system is that the one that is picked supplies the contrary 2. this is frequently because of the strategy that it doesn’t would like the most extreme sum energy to figure as power will. because of the arrangement and thusly how the gas valves will pack the air, it makes the machine run at a quicker speed, while not using a lot of energy. this is many times the clarification it’s the derrick game plan of bringing in fluctuated organizations.

Besides the popular business, you’ll have the option to in like manner find gas systems utilized inside the attendant staff:

All You Need To Know About Pneumatic Valves

All You Need To Know About Pneumatic Valves

Pneumatic valves control the tension, stream speed, bearing, and volume of air that travels through a pneumatic framework. Innumerable modern applications depend on simple frameworks to limit their force supply, and as the moderate in the machine is actually a liquid (as in a water-driven framework), the way it’s controlled and conveyed varies. There are additionally a few sorts of electric valves that can be utilized to control the tension and stream of liquid. The most widely recognized are strain help valves, stream control, and directional control valves. 

Stream Control Valves 

Pneumatic frameworks (just as water powered frameworks) every now and again contain stream control valves. The reason for this sort of tension valve will be to control the pace of the liquid from the PC framework. They are intended to respond to signals in the regulator meter or temperature check as are typically fitted with actuators and positioners. The 2 settings include either a variable limitation that opens and shuts the valve or one which permits stream 1 way while confining the opposite stream. 

Directional Control Valves 

As a stream control valve, directional control valves are a crucial component of pneumatic machines. The structure is part of an enormous gathering of pneumatic valves which have different variations, from a straightforward check valve to a more mind boggling valve utilizing fluctuating vents. Basically, they empower liquid to stream in different roads from grouped sources. The valve includes an administrator who moves the valve between positions. They comprise of a spool in a chamber which might be controlled either precisely. 

Different variations of Pneumatic Valve Exporter involve poppet valves and spool valves, each with their own particular provisions appropriate to this application they have been made for. When picking a pneumatic valve, examine that many accompany either customary or non-standard mounting arrangements. It is consistently fitting to get your work done prior to settling on a decision on the grounds that there are frequently irregularities between the different makers. In case you are uncertain where to begin or need counsel on a current framework, don’t be hesitant to call the Bearing Center group. We will joyfully help you in finding the pneumatic valve generally satisfactory for your framework. 

Airmax is a main pneumatic valve producer and exporter in India beginning around 1992. We have an enormous chain of fulfilled clients in the valve business.

Keeping Pneumatic Systems Efficient in Manufacturing

Keeping Pneumatic Systems Efficient in Manufacturing

Pneumatics serves various capacities in regular daily existence, particularly with regards to modern applications. As a result of their capacity to give compressed force in a less expensive, more adaptable, more secure, and more proficient way than utilizing an enormous number of actuators and electric engines, pneumatics are frequently utilized in assembling settings. 

For makers that depend on pneumatics, they rely on their tasks to stay effective, with as little vacation as could be expected. One of the manners in which producers guarantee dependability is using valve terminals. An advantage of pneumatic valve terminals is they require fewer independent valves and considerably less wiring than customary frameworks. 

Proficient pneumatic frameworks likewise decrease costs for producers by bringing down energy costs. As far as modern electrical energy utilization, compacted air age represents almost 10% of all energy use. Expanding effectiveness brings down the expense of creation, which thus aids the general manageability of creation. The energy use in pneumatic frameworks can be inspected from two unique perspectives. It very well may be seen as electrical energy use in the age and treatment of packed air, or as its utilization by end-client gadgets. 

A critical method to guarantee the most energy productivity in a pneumatic framework is to guarantee there are no holes. A hole is not difficult to spot in water-driven frameworks, as the liquid would be noticeable, however, an air spill is significantly harder to distinguish. The murmur of an air spill is not entirely obvious in an industrial facility setting with the typical commotions of creation hardware. Air spills cause a need to utilize more force and therefore, energy costs rise. A plant can lose up to 30 percent of its compacted air in case there are insufficiently kept up with pipe joints, couplings, or fittings. 

There are various regions to search for spills inside a pneumatic framework. For instance, old pipework can lose air through consumed joints. Another normal break course for air in the framework is through fittings that have become free. To guarantee fittings stay tight, be certain unreasonable strain has not been set in the fittings. A framework will undoubtedly go through mileage through day-by-day use, however, through close checking plant directors can guarantee everything is working as well as could be expected.

Common Pneumatic Valve Types for Engineers

Common Pneumatic Valve Types for Engineers

Chances are high that if you work in any type of lab or production environment with liquids or gases, then you are probably acquainted with a selection of classic corded valves. For a fast refresher: pneumatic valve help to control, handle and handle the number of media, liquids and fluids, which flow through a system.

Kinds of Pneumatic Valves

Fundamentally There are two quite different types of electrical valves. The first electric valve kind is where an inert gas is your pneumatic drive pressure. These type of valves operate or manage the origin air in an automated system. While frequently known as pneumatic valves, they can be actuated (operated) by manually, by pneumatic actuation, by solenoid actuation, or by motorized actuation. Ultimately, all of them serve the identical function: they modulate or control the source air for an automatic system. Based on the system specification and plumbing line dimensions, such pneumatic valves can be of a gate, plug, diaphragm, wedge, or ball design, to name a few.

These valves may be actuated on a variety of methods, however, their purpose is to handle the driveway air or inert gas. These electric valves are often controlling, controlling or managing Clean Dry Air (aka CDA) to get a production process. Those pneumatic devices in turn could be regulating procedure media or transferring mechanical systems.

The second sort of pneumatic valve is one where the press is really a process gas or fluid, which has been manipulated, controlled or managed by valve. The CDA or source air pushes the valve to position (open, closed or some partly open place ). The pneumatic valve, attached to its own telescopic actuator, will regulate the media flowing inside the process.

Both pneumatic valves for automation management and process fluid managing remain very common in business. While they’ve seen some displacement by means of electro – mechanical (servo & stepper motor driven) and hydraulic driven platform, pneumatic actuation stay a economical method of actuating valves. For many applications pneumatic are preferred; for instance, within the semiconductor sector pneumatic systems operate cleaner with much less positive-charged ions out of metals. Over the life science businesses, pneumatic systems run more sanitary for human and food safety.

A further distinction within the kinds of Pneumatic Valves available on the market can be seen in their porting configuration. Pneumatic Valves may be ported in a vast assortment of configurations. The industry segments valve porting into three key classifications: the port dimensions, the port style as well as the manners of this valve.

Port Sizing: Pneumatic Valve vent sizes can vary from less than 1/16″ to greater than 48″ in diameter

Port Ways: Pneumatic Valves may be design and manufactured as a 2-Way (the most simple inlet and outlet valve), 3-Way, 4-Way, as well as larger quantity of means. Multi Way Tasks are frequently used as Selection or Distribution Valves. Where one manner is dedicated since the inlet or outlet of the valve and another multiple ports (or ways) signify the choice or supply of media flow.

Pneumatic Valve Materials of Construction

Pneumatic Valves for automation controllers reside away from the process press. They are usually made with a mix of substance, which include: plated carbon steel, bronze/brassand stainless steel, and a wide array of industrial grade plastics (PVC, Nylon, Acetal, etc..)

Therefore the valve design does not need to take into account the aggressive corrosive nature of the networking or accounts for its high purity grade of their media.

Whereas, the Pneumatic Valves for process fluid managing the press is crucial. The media is one of the main selection criteria for picking the electric valve. These valves handle highly contaminated, corrosive alkaline and/or higher purity media. The designer should choose materials of construction for all wetted surface of the valve, and which are vulnerable to the press, to protect the media and the valve.

Polytetrafluoroethylene (PTFE) as a Construction Material

Pneumatic Valves for procedure fluid handling should first and foremost think about their stuff of construction. PTFE Pneumatic Valves are manufactured for crucial media procedure handling. Licensed virgin pure PTFE fabric is the first sintered Polytetrafluoroethylene (PTFE) without any sort of impurity or regrind or recycled plastic.

PTFE Pneumatic Valves can handle the harshest low pH acid, so the corrosive high pH alkaline, and the purest of media. By its character PTFE is extremely inert and extremely chemical resistant. It’s frequently one of the best material choices for Pneumatic Valves for process handling of critical media.

In later articles we will examine the procedure manufacturing of TeflonĀ® (the former signature of Dupont). TeflonĀ® is the world famous brand name for Polytetrafluoroethylene (PTFE). We will research where PTFE get its great chemical resistance, temperature performance, low friction properties and outstanding inertness.