Solo 425 4-Gallon Deluxe Piston Pump Backpack Sprayer nofreeship such as this one

such as this one

Comet BP series diaphragm pumps have external plastic or plastic coated manifolds for extra resistance to chemicals

D403 & D503 Pumps

Durand Wayland Silverline 736T 600 Gallon Air Sprayer w/ Diaphragm Pump (36" Fan & Tracking Hitch)

5 HP Electric Start Honda Engine

Solo 425 4-Gallon Deluxe Piston Pump Backpack Sprayer nofreeship such as this oneSolo 425 4 Gallon Deluxe Piston Pump Backpack Sprayer The 425 Deluxe includes the following upgrades: new carry handle and waist belt attached to deluxe shoulder straps, brass adjustable nozzle, adjustable pressure regulator with four settings (15, 30, 45 or 60 psi), extra large carrying handle with wand retainer for easy portability and easily reversible fold away handle. Easily and effectively handles disinfectants, fertilizers, herbicides,