... through the middle so that when the port is in line with both ends of the valve, flow will occur ... /2" ~ 6"Industrial grade, maintenance free sealed unit and compact design.EPDM or NBR O-ring seals. ... 70 countries. We have more than 10 years experience in irrigation field.America:USA, Canada, Ecuador, Peru, Chile ... ,Australia We are not the biggest one in the industry in our country ,but we believe we are ...