The Difference Between Solo’s Piston and Diaphragm Pump Sprayers

Since 1948 Solo has been recognised in the industry as one of the leading manufacturers of quality spraying equipment. We manufacture a huge variety of sprayers for different uses, and knowing the differences between our popular Solo sprayer models will make it easier to select a sprayer for your use.

Before you chose your sprayer, you need to work out what you’re wanting to spray as particular products are better suited to certain models. Our top selling 15L backpack sprayers are the model 425 and 475, so we’ve done a comparison on which is the right sprayer to go for.

The 425/435 models have a piston pump which produces a maximum 90 psi / 6 bar of pressure. A Solo piston pump features a cylinder housing in which a piston travels up and down to generate pressure. Most models can reach 60 psi but select models can reach 90psi with a pressure adjuster, and an optional plug installed (which comes as an extra in the box). The higher the psi, the smaller the droplet size.

This sprayer is ideal for contact herbicides, disease control on animals, and spot spraying, but aren’t recommended for use with wettable powders, marker dye, abrasive solutions, copper or bleach solutions which crystalise inside the piston, causing premature wear and failure of the pump. It is imperative when you’ve finished using these sprayers to flush them out with warm water.

The 475/473D models have a diaphragm pump with maximum output of 60 psi. The Solo diaphragm pump features a flat diaphragm inside the housing, which a diaphragm travels up and down to generate pressure. Because there is no contact with the cylinder wall as there is with the piston pump, these tend to be more durable and ideal for systemic herbicides, wettable powders, marker dye, copper and bleach solutions. The lower psi also produces larger droplet sizes for less drift. Using a diaphragm, these are equipped to handle the abrasive chemicals.

425 Comfort

• German manufactured
• A heavy-duty unbreakable wand
• Equipped with additional plug to maximise pressure (from 60 to 90 psi).
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• Rotating, length-adjusting pumping handle
• Professional shoulder straps
• Pressure adjuster
• Carry handle with wand holder
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

 425 Classic

• German manufactured
• A heavy-duty unbreakable wand
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

 425 LC

• Ideal for home / domestic use
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

 425 Domestic

• Ideal for home / domestic use
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

435 Classic

• German manufactured
• A heavy-duty unbreakable wand
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 20L tank size
  
  

475 Comfort

• German manufactured
• A heavy-duty unbreakable wand
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• Rotating, length-adjusting pumping handle
• Professional shoulder straps
• Pressure adjuster
• Carry handle with wand holder
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

475 Classic

• German manufactured
• A heavy-duty unbreakable wand
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 15L tank size

 473D

• German manufactured
• A heavy-duty unbreakable wand
• Ideal if you’re using your sprayer a lot / for commercial use and for longer periods of time
• L shaped handle
• Professional shoulder straps
• Large tank lids and filling aperture
• Easy action pump
• Changeable handle from L to R hand operation
• UV resistant plastic
• Comes with two nozzles – a fan nozzle and a hollow cone nozzle.
• 10L tank size