PUMPING SPEED OF DIAPHRAGM PUMPS FOR VARIOUS GASES

The modern diaphragm vacuum pump is established for the generation of rough and fine vacuum due to very good Vacuum technological data such as high pumping speed, high compression ratio, long lifetime of diaphr agms and valves, ease of maintenance, totally oilfreeness and its envi ronmental friendliness (especially of the chemistry version). The wide r use of diaphragm pumps made it necessary to introduce a new standard for the measurement of the pumping speed of this type of oscillating pump for achieving high accuracy and reproducibility (DIN 28432, Accep tance specifications for diaphragm pumps, Beuth Verlag, Berlin, German y). With this method pumping speed curves for Helium, Nitrogen and Arg on and ultimate pressures for one to four stage diaghragm pumps have b een measured and analysed on the basis of turbulent and laminar flow a nd thermal effects. Copyright (C) 1996 Elsevier Science Ltd.