Some thoughts  about pneumatics

0159.jpgIn the control of the different technological processes are applied   pneumatic solutions  increasingly.It’s not only a Hungarian phenomenon but it is a worldwide trend. Pneumatics already have demonstrated their capabilities in more industry  branches. One of the users the most important one is the paper industry. 

There are the processes tipically complex and complicated, the environment is agressive and the operating running  continuously.  In this area the requirement against control are very hard. Material with different consistency as water, mud , fibrous materials, pulp and pollutants are running through the stations of the procedure, they must be separated,  disconnected or have to be filtred. The pneumatic executive elements can give an optimal solution for example in operating of the butterfly valves working as actuators. They parts have a robust  structure ,are made of stainless material so they can meet with all operating requirement as variable velocity, have  finished surfaces, don’t need maintenance, can work in nonstop operating and can tolerate  overload also. It’s very important at the transport and selection of material.

The pneumatics give the driving force in the cleaner, washer and filter systems. There are various applications in the industrial branches.

In the food industry  in the usual procedures there are three different areas:  zone contacting with foods,  zone splashing, zone contacting not with foods.

In the zone contacting direct with foods can use only pneumatic elements planned especially for application on this area, have to be easy cleaning and can use only spezial lubricants. But there are areas in the food industry  where can use usual pneumatic elements also.These are water treating and filtration, dosing , mixing, cleaning and transporting of cleaning chemicals, or filling operations or removal sawage.

In the area of industry the alternativ energies have an increasing role. One of them is natural gas as a source of driving energy has an increase relevance. For example the cars operated with natural gas means an interesting alternative against cars operated with petrol. This days is current exercise operating the high pressure valves by pneumatic elements at the natural gas containers.These elements have a robust structure and don’t need maintenance. The working medium is pressed air, it is very suitable to build them in the explosive spaces. If it’s necessary the analog control can happen with explosion proof positioning elements controlled by electropneumatics.  

Preferences in the petrolchemical and chemical industries: The chemical and petrolchemical industries are using a lot of butterfly - or other type of - valves operated by hand or are equipped with pneumatic driving. In these fields of industries are regulations very strict, because such mediums are flowing in the systems are very agressive or explosive. 

For these situations are spezial designed pneumatic elements in our product sortiment.

0160.jpg - magnetic valves equipped with explosion-proof coils are installed direct on the drivers working locally in the explosive spaces.
 - magnetic valves are installed into an explosion-proof cabinet are connected to the drivers with pneumatic piping.

Pneumatics are in this solutions better and cheaper:

(Literature: Pneumatics in the control of processes fig 1./ Pneumatics in the site sawage. Hungarian Technical Magazine No.51 January –February  2004.)

 - magnetic valves installed into a control cabinet placed out of the explosive space connected to the driver with pneumatic piping.
 - islands of valves  placed out of the explosive space connected to the driver with pneumatic piping.

Comparison of pneumatic and electric solutions:

Let’s test  the advantages of pneumatics against electric solutions in the fields of treating technologies  of drinking water  and sawage. These areas are more and more important  in Hungary. We can show

witch  advantages have using pneumatics against electric solutions. A part of differences can be determinative and the comparison can be mostly remunaritive. 

Durability and life time:

The electric drivers are not chargeables for permanently loading they are not suitable for a continuous and controlled operation. The pneumatic power units are continuously chargeable and to the end of their life time need only a mimimum maintenance. There are not requirement of changing oil or spezial needs of lubrication. The pneumatic power units usually have a life time for 1 million cycles and they will survive all armatures.

Overload protection:

If the torque moment is increasing or the loading situation need  extra high effort, at   the electric drivers the overload limiting unit will operate very quickly.

Using of the  pneumatic drivers are more advantageous where the actuators are in opertating in irregular intervals or they are in operation very rarely.  For the subsidences or materials burned onto surfaces will increase the needs of the torque demand   for starting the move.It can reach the limit torque of the electric drivers. With using pneumatics this problem is solvable easily because we can increase the inlet pressure and the force and the torque will increase also.


In the fields of the treating drinking water and sawage the most actuators have to open or to close the way of the medium. or there is a possibility to operate them by hand . Using pneumatics can have a significant cost-cutting role. When a driving is solved by electric motors we have to take attention for overheating, for the greatness of torque, for the frequency of switches  as well as  the supervisor computer have to watch the periods of services and maintenances. All these needs a lot of inputs and outputs.

At the pneumatic drivers we need only  detection of the position and the supply of the inlet pressed air and don’t need other supervising or control activities. On account of the most favourable price is a remunerative investment a valve (operated by hand) to equip follow-up with automation by pneumatics.


At the big extended equipment or to realize safety functions the economical and safe pressed air supply can be realized with intermediate  reservoires located decentralized  or instead of a big reservoir located central to apply more smaller compressors locally.

Assembly is easy:

Pneumatics is not a complicated technique. The pneumatic driver   we can very simply to install onto the actuator. The pressed air supply we can very easy  connect to the driver and  the control unit  can be connect without problems also. Then the pneumatic drivers need only a minimum maintenance.


The pneumatic parts are vibration-proof, they structure is robust, have very long life time, they are practically undestructible.  The parts are resistants against corrosion and can tolerate the high temperature also. The electric drivers are complicated, they consist of a lot element and so they have more possibility for the malfunction.


At the decisions is the price a most important criterion. When we compare the electric and pneumatic solutions we have to  do difference between the price of the  single parts and the price of a whole system.The economical advantages of the pneumatics will be clear considering the whole system only.The consequently realized conception for installing pneumatic automation  applying valve islands  will result a significant cost saving compairing to the electric solutions, sometimes it can reach 50% or more also.The favorable cost of the pneumatic solution compairing to the electric one are resulted by the less investment costs and the less quantity of the needed inputs and outputs at the PLC controllers and by the less costs for installation and cabeling. There is an example worked out of a water treating equipment consist of 8 filter circuits  each equipped with 7 closing valves and operated with 3 bars pressure.The costs are compaired with pneumatic solution against electric one. The result is: of the two systems fulfilling same requirements the pneumatic system costs 1.9-2.5 times less then the electric one. Plus the costs can be reduced with applying double-acting drivers instead single-acting ones, or the signal flow can run on the industrial bus instead paralel cabeling.