Berthoud Cosmos 18 Pro 18 Litre Knapsack Sprayer

The Berthoud Cosmos 18 Pro is the highest-pressure knapsack sprayer in the Phoenix Amenity range, with a piston pump that reaches 6 bar. It also has a built-in agitator mixer that keeps the tank contents mixed throughout the treatment, which matters if you are spraying wettable powders or suspension concentrates that tend to settle in a standard tank.

It is also the best-value professional knapsack in the range, giving contractors a step up in pressure and mixing without the price tag of the top-tier machines.

A built-in mixer that keeps the tank properly mixed

Most knapsack sprayers simply pump liquid to a nozzle. As the contents settle or separate over the course of a treatment, application rates drift and spray quality suffers. The Cosmos 18 Pro’s agitator mixer is built into the pump itself, so it keeps stirring the tank as you pump, and the mix reaching the nozzle stays consistent from the first litre to the last. That matters most with wettable powders and suspension concentrates, the products most prone to settling.

Pump pressure: 6 bar

The Cosmos 18 Pro’s piston pump reaches a maximum working pressure of 6 bar. For comparison, the Cooper Pegler Classic range tops out at 3 bar and the Vermorel 1800 reaches 5 bar. The extra pressure helps with finer atomisation, better penetration into dense canopy, and nozzles or booms that need a higher inlet pressure to work properly. Stainless steel ball bearings in the air tank keep it leak-tight and reduce wear on the pump, so the pressure holds up over years of use.

Key features

Viton pump seal

The pump seal is Viton throughout, which resists the fungicides, herbicides and insecticides used in professional spraying for far longer than standard rubber seals. Viton is one of the most chemically resistant elastomers available, so the pump stays leak-free well after cheaper seals have started to fail.

Inner sloping tank base

A flat-bottomed tank leaves liquid pooling at the end of a treatment, which means wasted product and a disposal problem. The Cosmos 18 Pro’s sloping base channels what is left towards the outlet, so there is less waste and the tank empties and cleans faster. For anyone using costly plant protection products, that saving adds up over a season.

Large tank, wide filler opening

The 18-litre translucent tank gives enough working capacity for large-area professional spraying, and the 125mm filler opening is wide enough to fill quickly without spilling. A large anti-splash filter sits in the filler opening too, keeping impurities out of the spray system and cutting the risk of chemical splash while you refill.

Reversible pump lever

The pump lever swaps between left and right-hand operation without tools, so any operator can set the sprayer up to suit them in seconds. That is useful on contracting sites where the same sprayer is shared between several people during the working day.

Five-year guarantee

Like other Berthoud professional knapsacks, the Cosmos 18 Pro carries a five-year guarantee, reflecting the quality of the materials and build.

Full specifications

What’s in the box

• Berthoud Cosmos 18 Pro 18L knapsack sprayer
• Anti-splash filter
• Pressure regulator

Accessories and compatibility

The Cosmos 18 Pro takes the full range of Berthoud knapsack accessories, which are also cross-compatible with the Vermorel range, so operators running both Cosmos and Vermorel sprayers only need to stock one set of spares and fittings. Useful accessories include:

• Extended telescopic lance tubes for reaching taller vegetation
• Multi-nozzle boom kits for wider application widths
• Spray shields for targeted spot treatment with reduced drift
• Flat fan, hollow cone, evenspray and deflector nozzle options
• Replacement Viton seals and service kits

Ideal applications

The Cosmos 18 Pro suits jobs where high pressure, tank capacity or the built-in mixer make a real difference, including:

• Herbicide application on paths, car parks, highway verges and hard surfaces
• Weed control across large amenity planting schemes and landscape contracts
• Wettable powders or suspension concentrates that need continuous agitation
• Fungicide and insecticide treatment on ornamental planting, shrubs and hedgerows
• Grounds maintenance on sports pitches, golf courses, parks and public open spaces
• Estate, farm and forestry management
• Any job where maximum pump pressure improves penetration or atomisation

Professional pesticide use

Anyone applying pesticides professionally in the UK needs a PA1/PA6 certificate of competence, or an equivalent qualification. The Berthoud Cosmos 18 Pro is manufactured to European safety standards for professional spraying equipment. Regular calibration and maintenance keep application accurate and compliant throughout the sprayer’s working life.

Berthoud: over 130 years of spraying equipment

Berthoud has been making professional spraying equipment since 1895. Like other Berthoud products, the Cosmos 18 Pro is built at the EXEL Industries factory in France. Spare parts are available for all machines, and the five-year guarantee covers your investment from day one.

Looking for something different? If operator comfort and lighter pumping effort matter more than outright pressure, the Berthoud Vermorel 1800 is worth a look. Prefer the Cooper Pegler range? The Cooper Pegler CP15 Classic is a well-established 15-litre professional knapsack, while the Cooper Pegler CP3 Classic offers the same design in a 20-litre format for higher-output work.

Want help comparing the Cosmos 18 Pro with the Vermorel 1800 or the Cooper Pegler Classic range? Contact the Phoenix Amenity Supplies team. We specialise in professional amenity spraying equipment and are happy to help you pick the right sprayer for your operation.