This Shurflo high pressure pump (replaces the 8000-543-138) model has an internal bypass and it has proven to be a real workhorse when it comes to agricultural chemical spraying.   With a 1/2" male inlet and outlet, Santoprene diaphragms and Viton seals, it is very suitable for most Ag chemical sprays, requires a 7.5 Amp fuse and comes with 1/2" nut x 10mm barbed elbow and 10mm straight hose barb.   We recommend the use of 12mm hoses with this pump particularly on the discharge side of the pump to eliminate friction loss and pressure loss.   With a maximum flow rate (at zero pressure) of 6.8 L/minute and a maximum pressure of 100 psi or 700 kPa, this automatic pressure switch pump is very versatile and reliable where a higher pressure is required.  Click here for the spec sheets.    Click here for adaptors.