Warning!Can not use for corrosive liquid.Specifications：Product: Diaphragm pumpType: Double diaphragmOperation Type: Air-operatedModel: QBY4-25LBody Material: AluminumInlet Port: 1 inch (25 mm)Outlet Port: 1 inch (25 mm)Air Inlet Size: NPT 1/2 inch (12.7 mm)Average Air Consumption: 38 CFMMax Flow Rate: 9 m3/h (35 GPM)Suction: 0-5 m (0-16.4 ft)Max Suspended Solids: 3 mm (1/8 inch)Max Head: 84 m (275.59 ft)Max PSI: 120 psiMax Temp.: 150 ℉Self-Priming Dry: 3 m (10 ft)Self-Priming Wet: 4.6 m (15 ft)Manifold Connection: SingleValve Type: BallBall Material: AcetalCheck Seat Material: PolypropyleneDiaphragm Material: NitrilePackage Size: 35 x 26 x 23 cm (13.78 x 10.24 x 9.06 inch)Gross Weight: 9.86 kg (21.74 lbs) Package Content：1 x Air-Operated Double Diaphragm Pump1 x Product ManualWorking Principle：In the pump two symmetrical working chamber each equipped with a diaphragm, the center link will be integrated into one. Compressed air from the pump inlet into the valve, through the valve body to introduce compressed air into one of the chamber to promote movement of the diaphragm chamber, while the other chamber gas emissions. Once the end of the stroke is reached, the gas distribution mechanism automatically introduces compressed air into the other working chamber to push the diaphragm in the opposite direction so that the two diaphragms move back and forth in unison.