Choosing a knapsack sprayer
Know what to look for in a new knapsack sprayer. Check if your current knapsack is fit for your planned use. Learn how common types of knapsack sprayers work.
Will the knapsack sprayer do the job I need?
Is the knapsack sprayer fit for the purpose?
Types of knapsack sprayers
The most common types of knapsack sprayer are:
- compression sprayers: for smaller areas and spot spraying;
- side lever, diaphragm pumped: for larger areas and lower pressure spraying;
- side lever, piston pumped: for larger areas at higher pressure spraying;
- electric powered knapsack sprayers: for easier spraying over long periods of time;
- mistblowers: to blow small drops long distances and through dense leaf canopies.
How hand operated knapsack sprayers work
The operator carries a tank of spray mix on his back or over his shoulder. Straps are fixed to this tank to ease the load on the operator and to make the sprayer secure when being carried and used.
Spray is formed by forcing the spray mix from the tank through a flexible hose, an on/off trigger valve, the rigid lance and then to the nozzle.
The force on the spray mix is applied directly or indirectly. For:
- Side lever sprayers, the operator uses an up/down action on a lever, which activates a pump, which forces the spray mix towards the nozzle.
- Compression sprayers, the operator uses a pump to compress the air above the spray mix. The compressed air forces the spray mix towards the nozzle.
Motorised knapsack sprayers may use batteries or small engines to power the pump. Some hand operated sprayers may also have powered fans that blow air to carry the spray from the nozzle.
Side lever sprayers
When using side lever knapsack sprayers, lift the side lever up and then push down. This forces the spray mix towards the nozzle. Practice pumping at the right pressure to get the flow rate that you need.
Side lever diaphragm pumped knapsack sprayers
Side lever, diaphragm pumped sprayers are useful for larger areas and lower pressure spraying.
Side lever piston pumped knapsack sprayers
Side lever, piston pumped knapsack sprayers are useful for larger areas at higher pressure spraying;
Compression sprayers: For smaller areas and spot spraying
Compression sprayers are useful for smaller areas and spot spraying.