Introduction: 2BV series liquid ring vacuum pump is suitable for suction gas and vapour ,and the suction pressure can reach 33mbar (abs.)(i.e.97% vacuum degree ).When the liquid ring vacuum pump works under the condition that the suction pressure is near the limited vacuum (saturated pressure of the operating liquid )for a long time ,it should couple with the cavitation protection pipe in order to protect the pump .When it’s used as a compressor ,the maximum pressure is 0.26mpa（abs).As a new generation of energy-saving product ,2BV series liquid ring vacuum pump will replace the SK and 2SK series liquid ring vacuum pumps and W,WY,WL series reciprocating vacuum pumps completely with their superior performance and advantages . 2BV6 series liquid ring vacuum pumps and compressors are mainly used for pumping the explosive gas or working in the flammable and explosive environment .The technical parameter of each type is the same as the corresponding type of the 2BV2and 2BV5 series products