Overpressure control in mini-environments and hygiene rooms


Modern pressure measurement technology – a must in the pharmaceutical industry


For the production and packaging of active ingredients in the pharmaceutical industry, hygiene is an important factor in determining the purity and efficacy of medications. Production therefore takes place in defined hygienic areas. A stable overpressure prevents the penetration of particles from adjacent production areas. Differential pressure transmitters can be used for overpressure control in hygiene rooms.

Whether the tablets or powders are packed in blister, glass or plastic containers, whether serums are filled into phials, syringes or glass bottles – the production environment must meet the highest standards of cleanliness at all times. The state-of-the-art processes and packaging machines used by the pharmaceutical industry offer various possibilities for creating such a production environment. The first option is to place the entire production line in a traditional cleanroom. The second is to use a series of separate, sterile hygiene cabins. The third possibility is to use delimited areas – or so-called “mini-environments” – within the machine for sensitive stages of production. Each of these three options ensures that individual process steps, such as filling or packaging, take place under cleanroom conditions. In these sensitive production areas, the supply and exhaust air are regulated and monitored. A controlled, stable overpressure prevents particles entering the cleanroom from adjacent production areas.

Filling in mini-environments in modern pharmaceutical machineszoom
Filling in mini-environments in modern pharmaceutical machines

Filter systems ensure the supply air is perfectly cleaned. The requirements for the production facility are specified by statutory requirements and a range of national and international standards. These are supplemented by behaviour and clothing regulations for employees. Sensitive pressure measuring technology is usually required to maintain the stable overpressure within the prescribed range. The ventilation system filters are also monitored by differential pressure transmitters. This is important for ensuring that there is a reliable air supply for controlling the overpressure and that the system operates efficiently using the minimum energy. Pressure measurement technology is thus part of an overall control system that regulates and monitors all fans, air distributors and air filters. To maintain a constant overpressure, a differential pressure transmitter continuously measures the pressure difference between the sensitive production environment and surrounding production areas. The smallest changes in air pressure are translated into an electrical signal and passed on to the control system. As soon as the pressure difference falls below a specified value, or if there are major fluctuations, the control system issues a warning to higher level systems or initiates a controlled interruption of production. Production is halted and a servicing operation begins. Once the root cause has been discovered and remedied, the prescribed production conditions must be re-established before production can resume. For the plant operator, this is a costly and time-consuming process that results in significant loss of production. Highly sensitive, accurate measuring technology is essential in order to guarantee product safety and process quality in machinery and equipment operated by the pharmaceutical industry.

Optimum measurement technology for process and packaging machines


halstrup-walcher supplies a variety of differential pressure transmitters for overpressure control and filter monitoring in process and packaging machines. All devices from the specialist manufacturer with over 40 years of experience in the field of metrology have the following features: They are stable measuring systems for lowest air pressures in the lower Pascal range. The portfolio includes a wide variety of designs with various pressure and electrical connection options, interfaces and parametrisation settings, including the functions described above for zero-point calibration and adjustment. Service from halstrup-walcher is outstanding and features an established QM system and short delivery times. It always meets the quality standards that global customers expect of products “Made in Germany”.

Differential pressure transmitter from halstrup-walcher - the right instrument for every applicationzoom
Differential pressure transmitter from halstrup-walcher - the right instrument for every application

The PU/PI, P27 and PS17 transmitters are reliable base units with excellent long-term stability that deliver reliable measurement results over many years. The PU/PI version is available with a limited number of additional functions and is sufficient for basic applications. The PS17 offers more options and greater flexibility due to its small size. The P26 and P34 transmitters are high quality devices with outstanding precision and a wide range of adjustable functions, e.g. for volume flow/mass flow measurements. Setting and parameter adjustments can be performed either via a free PC program or an operating menu (with optional display). The P34 impresses with its exceptionally slim and compact housing design. This allows several devices to be mounted side by side in the control cabinet. Bundling all the pressure transmitters in the central control cabinet enables calibrations to be performed more quickly and efficiently. halstrup-walcher is the ideal supplier of reliable, high precision pressure measuring technology required by sensitive production
areas in the pharmaceutical industry.