Burkert Fluid Control Systems offers a versatile range of automation and
control technologies designed for processes of all sizes.
Pneumatic process control systems are increasingly being adopted by
various processing plants; however, the growing complexity of these control
systems has resulted in factors such as reliability, integrity and correct
specification becoming even more critical. Not every system requires large
format valves, or fieldbus communication to achieve the required level of
automation.
In use for many years, especially in the pharmaceutical and food and
beverage industries where hygienic conditions must be maintained, pneumatic
control systems offer several advantages, including simplicity of design, low
maintenance, and excellent reliability partly due to the use of compressed air
as the power source. Being intrinsically safe, pneumatic systems can also be used
in hazardous atmospheres.
Modern control systems can be divided into two groups, centralised and
decentralised. Centralised systems will have the main control functions grouped
at a central point or located at the point of control, such as a process control
valve. This system will usually involve a control panel containing a bank of
control solenoids connected to the process control valves using air lines
alone. In a decentralised system, the air supply is fed direct to the control
valve and the integral control head uses control signals to determine the action
required.
The choice of system is dependent on the application since both have
their advantages depending on the circumstances.
Once the design scope is confirmed, it is important to ensure the proposed
design will produce an effective and efficient control system that will be easy
to maintain, expand, and clean to the required standard.
The first step is to clean and regulate the compressed air supply to the
control system using air preparation units that filter and regulate the air
supply. These units remove water and oil aerosols while also controlling the
system air pressure, all of which ensure correct operation of the system as
well as reduced wear and corrosion of the components.
Burkert offers standardised filter-regulator air preparation units, with
and without isolation valve kits, for all manifold sizes. Air preparation units
are available with a range of filter sizes, down to 0.01μm along with the
option of an activated carbon filter that can remove oil aerosols to a level of
less than 0.005 mg/m³. A range of connection sizes is also available in
addition to explosive environment certification to comply with regulations when
operating in hazardous atmospheres.
Flow restrictors, one-way valves and check valves will all be needed as
the system takes shape – all these components will need to be matched to the
application with regard to construction material, sealing properties and
connection sizes to ensure reliable and efficient service.
For instance, the type TRG001, also from Burkert, contains a complete
range of restrictor valves, check valves and flow control valves, with
non-standard versions, materials and seals also available.
All of this equipment will need to be connected together, requiring
careful selection of threaded or push-in connectors or a combination of both. Again,
the application determines the correct design of connector, especially the material
choice, which could require FDA approval or the corrosion resistance of
stainless steel.
Burkert has developed a wide range of individual products for use in
pneumatic process control systems as well as a process for designing, building,
installing and commissioning complete systems.
Burkert’s experience and expertise span a wide range of projects from
the simplest closed loop control system to the largest factory wide production
facility with the latest fieldbus communications and intelligent control
valves.