... its outstanding performance and advantages will replace SK, 2SK series water ring vacuum pump, W, WY, WL series reciprocating vacuum ... pump.Advantage2BV series pump for air and water vapour pressure to breathe, 33mbar absolute pressure (97%), vacuum ... use viton or PTFE.2BV2 - Ex, 2BV6 series water ring type vacuum pump/compressor is mainly used for surking explosive gas ...