2bv series water ring vacuum pumps are suitable for pumping the gases and steam. its suction pressure can reach 33mbar (abs) (i. e. 97 % vacuum degree). if the transformer oil is used as the operating liquid, these pumps are called oil ring vacuum pump and the suction pressure can reach 6.7mbar (abs) (i. e. 99 % vacuum degree). so the oil ring vacuum pumps can replace the reciprocated vacuum pumps completely. when the liquid ring vacuum pumps work under the condition near the limited vacuum for a long time, it is necessary to couple with the cavitation protection pipe in order to get rid of the screaming and protect the pump.

when the compressor is working, the maximum pressure is 0.26mpa (abs). and the higher of discharge pressure, the larger of the power of the compressors. so it is necessary that the data of the discharge pressure is provided to choose the proper motor.
2bv2-ex, 2bv6 series water ring vacuum pumps and compressors are mainly used for pumping the explosive gases or work in the flammable and explosive environment. the technical parameter of each type is the same as the corresponding type of the 2bv2 or 2bv5 series products.
2bv series stainless steel pumps can be used under the conditions with higher requirements for the corrosive-proof or the lustration.

according to the working situation, the material of all the parts where the liquid flows (i. e. pump casing, pump cover, port plate, and impeller)are made of various stainless steel as bellow:
sus304 (0cr18ni9), sus316 (0cr17ni12mo2), sus316l (00cr17ni14mo2)
the material of the shaft is 2cr13 or 0cr18ni12mo2ti
the mechanical seals are used the john crane products and the seals material is optional for fpm or ptfe.

2bv series products possess the characteristics as bellow
· the close-coupled design is convenient to install and can save space.
· the standard seals are all used the john crane mechanical seals.
· 2bv series products have the cavitation protection port. when they work under the condition near the limited vacuum, the cavitation protect port opens (or connects with the separator)to get rid of the screaming to protect the pump.

· aluminum bronze impeller is of high intensity and wearing well. the erosive-proof capacity of the pump can be improved by using it. if the parts where the liquid flows are made of the stainless steel, the pumps can be used under the more rigorous condition.
· the unique design of the discharge port can protect the pump from the over-pressure to ensure the best efficient performance in the working range of the pump.
· the motors are all adopted y2 series products. the protection class is ip54 or ip55 (normal is ip44) and the insulation grade is f.· the bearings are all used the imported products with brand name of ntn or nsk.