On the base of deeply researching overseas adcancde technique,according to the present-day practical demands of gas-oil mixed transporting,2W.WH--type out board bearing double suction dualscrew multtiphase mixed transporting pump and 2W.Wseries double screw pump are researched and deceloped by our company,then we follow the regulations of the national standard GB11035-89 and produced it.Through engagement together between dricing srew and driwen screw and the match between screw andpump body hole,and then form many sealing empty cacities,when the screw is rotational,these sealin empty cavitiel move ahead continually,push the liquid in the sealing cavity to the exit and then discharged,so the purpose of transporting the liquid can bei relized.