Page 20 of catalogue Diaphragm Compressors of Andreas Hofer Hochdrucktechnik GmbH

Hofer Diaphragm compressors

page 20 of 20

The DIN EN 1012 - standard, valid for Compressors, and other technical regulations covering the actual state of technology are stipulating, that the compressor is stopped immediately in case, the operational situation becomes critical. In addition to the diaphragm failure indicator, typical for the described type of diaphragm compressor, and depending on possible hazards originating from the compressor (high pressures, large flows, dangerous process media), following supervising instruments have to be provided: • limit switch and indicator for suction pressure and -temperature • limit switch and indicator for interstage pressure and -temperature • limit switch and indicator for discharge pressure and -temperature • safety valve for each stage Further monitoring instruments, such as • flow switch to avoid cooling water shortage • flow switch to avoid Hydraulic oil shortage • differential pressure gauges for filters • vibration control are often requested by the customer to get additional equipment for increasing the operational safety. Increasing rationalisation in most companies requires more and more a fully automatic control of the compressor. The conventional way of a relay control is steadily losing importance and is mainly replaced by the PLCs, the programmable logic controls. The PLC is flexible and can easily be incorporated via various bus systems into a modern process Control systems.

7. Summary
Diaphragm compressors are in use for decades already in industrial application and there they meet the specified demands for operational safety, availability and economical efficiency. When designing production Plants, they help to comply with environmental requirements, they simplify production processes, where the purity of the compressed gas is an important factor and their very smooth running is a special merit. Their figures of suction capacities cover the range of some litres / hour up to several 100 m 3/h. Discharge pressures of up to 3000 bar can be achieved with diaphragm compressors.

Literature: [1] Küttner, Kolbenverdichter, Springer Verlag, Berlin 1991 [2] Baehr, Thermodynamik, Springer Verlag, Berlin 1984 [3] Fröhlich, Kolbenmaschinen, Springer Verlag, Berlin 1968 [4] Internal reports of Andreas Hofer Hochdrucktechnik GmbH