Premium Double Nitrile Diaphragms: Our air-operated double diaphragm pump adopts nitrile diaphragms, durable, corrosion-proof, and long-lasting. Max. Temperature: 150 /66 ; Max. Pressure: 90 psi; Max. Flow Rate: 3 GPM; Max Head Lift196.85 ft/60 m±15%. Sturdy & Leak-proof Construction: The diaphragm pump housing is made of cast iron material, bolted against leakage, sturdy, and corrosion-proof for long-time use. Excellent Air-operated Performance: Inlet/Outlet Port Size: 1/2 inch; Air Inlet Size: FNPT 1/4 inch. A high-quality glyd ring, the double-acting sealing, strengthens air performance. Unique & Professional Designs: Our double diaphragm pump features an externally available air distribution system. The modular air valve is stainless. This low pulsation air valve provides smooth and rapid changeover for increased efficiency and minimizes downtime