Vacuum diaphragm pumps can be classified into motor-driven, electromagnetic-driven and piezoelectric-driven types according to the different driving methods. According to the number of pump head stages, they include two-stage pumps. According to corrosion resistance, they can be divided into ordinary type and corrosion-resistant type, the latter usually adopts a full PTFE (polytetrafluoroethylene) flow path design.
VB-40 corrosion-resistant diaphragm pump is a two-stage pump with a PTFE pump head. Its ultimate vacuum is 15-20 mbar and its maximum flow rate is 35 L/min. KNF N 920 G is a high vacuum diaphragm pump with an ultimate vacuum of 2 mbar and a pumping speed of 21 L/min. It adopts a PTFE-coated diaphragm and a variable frequency motor. ULVAC DTC-41K is a chemically highly corrosion-resistant diaphragm pump with an ultimate vacuum of 1000 Pa. Its pumping speeds at 50 Hz and 60 Hz are 40 L/min and 46 L/min, respectively. The KNF N 035.1.2 AN.18 is a dual-purpose vacuum and pressure pump with a vacuum of 100 mbar, a pressure of 4 bar, and a pumping speed of 55 L/min. The B40-8-YK is a two-stage corrosion-resistant pump with an ultimate vacuum of 6-8 mbar, a maximum flow rate of 40 L/min, and operating noise below 55 dB. In addition, the EYELA small variable frequency diaphragm vacuum pump series also includes models such as the DTC-22, DTC-41, and NVP series.
