2、eGroupXuLei(HunanSANYPolytechnicCollegeEngineeringclass1004-5,2010)Abstract:The pump main valve group is an integral part of the pump.Inthispaper,thestructureofthepumpmainvalvegroupisintrouduced.Thehigh&lowpumpingraleoillineisstudyedthroughthepumpmainvalvegroup’sschem