QBK Series new pneumatic diaphragm pump is designed and manufactured for various corrosive liquids and liquids with solid grain and high viscosity and volatile and flammable and toxin liquids on the base of QBY series pneumatic diaphragm pump. QBK series pump has the advantages such as long life and better anti-stall performance etc. 9 Specification: φ8mm(5/16''）,φ10mm（3/8''）、φ15mm（1/2''）、φ25mm（1''）、φ40mm（11/2''）、φ50mm（2''）、φ65mm（21/2''）、φ80mm（3''）、φ100mm（4''）。 4 materials of pump body: Aluminum alloy, cast iron, stainless steel, engineering plastic. Diaphragm materials: NBR, Neoprene, Fluorine plastic (Viton), Teflon(FEP/F46)/PTFE for different medium