Berthoud Cosmos 18 Pro 18 Litre Knapsack Sprayer

The Highest Pressure. The Built-In Mixer. The Best Value in the Range.

Most professional knapsack sprayers do one job: they pump liquid to a nozzle. The Berthoud Cosmos 18 Pro does rather more than that. Its high-performance piston pump reaches 6 bar of maximum pressure, the highest of any sprayer in the Phoenix Amenity range. Furthermore, it incorporates a built-in agitator mixer within the pump itself, continuously keeping the tank contents homogeneous throughout the treatment. For professional operators using wettable powders, suspension concentrates, or any product that tends to settle or separate in the tank, this is not a minor convenience. It is a fundamental improvement in spray quality and application accuracy.

Additionally, the Cosmos 18 Pro is the most keenly priced professional knapsack in the range. Consequently, it is the natural choice for contractors who need reliable, high-pressure professional performance without committing to a premium price point.

The Feature That Sets It Apart

A Built-In Mixer. A Better Result at the Nozzle.

Every knapsack sprayer on the market will pump liquid to a nozzle. However, not every sprayer keeps that liquid properly mixed throughout the treatment. As products settle or stratify in a conventional tank, application rates drift and spray quality becomes inconsistent. The Cosmos 18 Pro solves this directly. Its integrated agitator mixer, built into the pump mechanism itself, continuously homogenises the tank contents as the operator pumps. As a result, the liquid reaching the nozzle is consistent from the first litre to the last. For professional applications where accurate, even distribution is critical, this is a genuinely important advantage.

6 Bar Pressure. More Than Enough for Any Application.

The Cosmos 18 Pro’s piston pump reaches a maximum working pressure of 6 bar. By comparison, the Cooper Pegler Classic range tops out at 3 bar, and the Vermorel 1800 reaches 5 bar. Therefore, the Cosmos 18 Pro is the right choice where higher pressure is operationally important, whether that is achieving finer atomisation, improving penetration into dense canopy, or working with nozzles and booms that require higher inlet pressure to perform correctly. Moreover, stainless steel ball bearings in the air tank provide perfect anti-leak tightness while simultaneously reducing wear on pump components. Accordingly, the high-pressure performance is maintained consistently over the long term.

Key Features and Benefits

Viton Pump Seal

Chemical Resistance Built to Last.

The Cosmos 18 Pro uses a Viton pump seal throughout, providing long-term resistance to the full range of professional fungicides, herbicides, and insecticides in common use. Viton is one of the most chemically resistant elastomers available and maintains its integrity under repeated exposure to aggressive formulations that would rapidly degrade standard rubber seals. As a result, the pump continues to perform and remain leak-free long after cheaper alternatives have begun to fail.

Inner Sloping Tank Base

One of the most practically useful features of the Cosmos 18 Pro is its inner sloping tank base. On a flat-bottomed tank, residual liquid pools at the end of treatment, creating waste and a disposal problem. The sloping base of the Cosmos 18 Pro channels remaining liquid towards the outlet, minimising residual waste and making the tank faster and easier to empty and clean. For professional operators working with costly plant protection products, furthermore, this reduction in waste has a direct and ongoing commercial benefit.

18-Litre Tank with Large Diameter Filler Opening

The 18-litre translucent tank provides a practical working capacity for large-area professional spraying. The wide 125mm diameter filler opening additionally makes filling faster and cleaner than on narrower-necked competitors. A large-volume anti-splash filter is also built into the filler opening, keeping impurities out of the spray system from the moment of filling while simultaneously reducing the risk of chemical splash during the refill process.

Reversible Left or Right-Hand Pump Lever

The pump lever is fully reversible for left or right-hand operation without tools. Any operator can therefore set up the sprayer to suit their preference in seconds, which is particularly useful on contracting sites where equipment is shared between multiple operators during the working day.

Five-Year Guarantee

Like all Berthoud professional knapsacks, the Cosmos 18 Pro carries a five-year guarantee. This reflects the quality of materials and construction throughout and provides professional buyers with meaningful long-term reassurance.

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 is compatible with the full range of Berthoud knapsack accessories, all of which are also cross-compatible with the Vermorel range. As a result, operators running both Cosmos and Vermorel sprayers need only one set of spare parts and fittings. Particularly useful accessories include:

• Extended telescopic lance tubes for additional reach when treating 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 is particularly well suited to applications where high pressure, large tank capacity, or the built-in mixer provide a practical operational advantage. In particular, it excels in the following situations:

• Herbicide application on paths, car parks, highway verges, and hard surfaces
• Weed control across large amenity planting schemes and landscape contracts
• Applications involving wettable powders or suspension concentrates that require 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 application where maximum pump pressure improves penetration or atomisation

A Note on Professional Pesticide Use

Anyone applying pesticides in a professional or commercial capacity in the UK must hold a PA1/PA6 certificate of competence or an equivalent qualification. Accordingly, the Berthoud Cosmos 18 Pro is manufactured in compliance with European safety standards for professional spraying equipment. Regular calibration and maintenance will therefore ensure accurate and compliant application throughout the sprayer’s working life.

Over 130 Years of Spraying Expertise. Exceptional Value.

Berthoud has been manufacturing professional spraying equipment since 1895. Like all Berthoud products, the Cosmos 18 Pro is produced in the EXEL Industries factory in France to exacting European standards. Spare parts are available for all machines, and the five-year guarantee means your investment is protected from day one. Ultimately, if you need an 18-litre professional knapsack sprayer that delivers the highest pressure in the range, keeps your spray mix properly homogenised throughout treatment, and comes backed by over 130 years of manufacturer expertise, the Cosmos 18 Pro is an exceptional product at an exceptional price.

Not sure the Cosmos 18 Pro is right for you? If operator comfort and reduced pumping effort are the priority, take a look at the Berthoud Vermorel 1800. If you prefer the Cooper Pegler range, the Cooper Pegler CP15 Classic is Britain’s most trusted 15-litre professional knapsack, while the Cooper Pegler CP3 Classic offers the same legendary reliability in a 20-litre format for higher-output work.

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