Advantage: 2 inch   1. Fluid pressure is up to 7 bar. 2. Pilot-operated valve can be repaired during work, no nee to open the central body. 3. The epoxy coating. Can protect from bad wok condition.     RD series air operated diaphragm pumps' sizes vary from 1/4 to 3 inch inlet/outlet, The pump body is made of various material, including PP, acetal, PVDF, Al, SST, CI, etc, which with high quality and good-looking appearance, is very similar to Graco's, but much cheaper than it.     Type   RD50 Suction size   2in Discharge size    2in Air inlet size 1/2in Suction lift 5m Max.air pressure 7bar Max.flow      570 l/min Max.head   70m Max.grain diameter 6mm Weight   27~65kg  Material of Body PP. PVDF, AL. SST304/316.CI