Tech-Know - Pneumatic Control Systems

The pneumatic control HVAC system is most definitely underrated in engineering and one we at Advanced Control Solutions rate rather highly. They are used worldwide in many applications some of which we would not be without today and so with this, we would like to discuss these control devices and how they can benefit your business for the better.

The economical systems of pneumatics is a branch of engineering that uses compressed air and/or gas to conduct and control energy. They perform very similarly to that of the function of hydraulic systems yet they transfer compressed air and gases instead. These intricate pneumatic devices are used in everyday practice and utilise their pressurised air as a method of control for HVAC systems.

Industry uses vary from large manufacturing warehouses to factory applications where the pneumatics controls perform a multitude of tasks as well as easy adaptation for smaller monotonous tasks. For these two reasons alone, these systems are favourable for their use in heavy machinery such as drills, due to their repetitive action that the device performs.

How Do Pneumatic Controls Work?

These devices use compressed air as a method of control for HVAC systems. The compressed air is carried via copper and plastic tubes from a controller to a control device, usually a damper or valve actuator. This control method relies on sensors and thermostats that bleed or retain the line pressure from the sensor to the control device and the actuator. Each sensor responds to changes in temperature, humidity, and static pressure to provide feedback in a control loop to open or close the actuator to meet the control set point. The actuators contain diaphragms and spring to function in sequence with the control signal. This system uses compressed air as the communication method. Each thermostat in a building with a pneumatic control system has one or more air lines connected to it from the main source of compressed air and to some type of final device such as a valve.

Why do we use Pneumatics?

Pneumatic control systems are used in a variety of industries; one of which being in manufacturing facilities to power factory automation; with this comes low initial and ongoing maintenance costs. These control systems are more cost effective in mechanical movements therefore, when compared to electric systems, pneumatic wins every time due to its simple design, simplicity and compressed air mechanism.

Due to the simplicity of these devices, a combination of tasks can be performed at one time in automated equipment from simple gripping tasks to positioning and stacking in warehousing and manufacturing environments. Furthermore, tasks requiring precision such as pressing and high levels of tension are also possible.

Actuators
Pneumatic actuators, the air-powered "motors" which control valves and dampers, remain the most reliable, durable, and economical actuators available. They require essentially no maintenance except for inspection and adjustment of the mechanical linkages. It is easy to select actuators which fail in the desired position upon loss of electric power (and thus pneumatic air pressure). Pneumatic actuators, of all sizes, cost much less than corresponding electric/electronic actuators.

Modular control components
The complete pneumatic control system "brains" are distributed throughout the specific building using numerous pneumatic building blocks such as thermostats, receiver controllers, and pneumatic relays. Virtually any control strategy can be implemented by a custom-designed pneumatic control system. Pneumatics can provide excellent control performance and can maintain setpoints accurately. The ease and flexibility of these systems provides the end-user with a simple and highly cost-effective solution.

Maintenance of Pneumatic HVAC Controls

To keep these compressed air systems in check, they require two important types of maintenance. The first is to ensure that the pneumatic air supply is clean, reliable, and dry at all times. The second is to carry out a program of routine and preventative maintenance under which all control components are inspected and, if necessary, adjusted every couple of years or so. (If left unattended, pneumatic controllers and thermostats may eventually drift away from setpoint consequently the energy has been removed from the variable concerned.)

For many commercial buildings, the best way to maintain pneumatic controls systems is to have a continuous service contract with an external company. At Advanced Control Solutions, our mechanical engineers service and maintain pneumatic control systems for industrial, commercial and institutional facilities. We provide preventative maintenance contracts of many sizes depending on your bespoke requirements.

Benefits of Pnematics Systems

As highly effective and durable systems, their use of pressurised air can be easily transported through many devices. Economically, after use, this compressed air can be released back into the atmosphere without any need for extra handling. No chemicals are released when pneumatics are in operation, making these systems a favourable environmental option.

However, as previously mentioned, we feel the main benefit of using pneumatic control systems is their sheer low cost to run due to their low maintenance fees. Additionally, their durability demonstrates their costs of maintenance and repair are greatly lower than many other systems on the market.

How can Advanced Control Solutions help your business?

Pneumatic Controls Service and Repair

• We offer regular service, overhaul and repairs for all makes and models of pneumatic control systems
• Fully qualified engineers on every call out and project
• Air compressor maintenance and repair
• Calibration of pneumatic thermostats
• The troubleshooting, diagnosis and repair of pneumatic main and line air pressure problems
• Retrofit to direct digital control (DDC) pneumatic wireless thermostats for standalone operation or for interface to building DDC system
• Retrofit of pneumatic valves with DDC actuators or E/P transducers
• Repair and replacement of faulty pneumatic devices such as thermostats, valves, damper actuators, air dryers, regulators and receiver controllers
• Ongoing preventive maintenance contracts for entire pneumatic systems

Our mechanical team have the expertise to carry out a diverse range of associated services for your pneumatic systems keeping them maintained throughout the year. Please get in touch with our team today or alternatively call us on 01483 237812 and we will be happy to assist you with your enquiry.