Cooper Pegler CP3 Classic 20 Litre Knapsack Sprayer

The Sprayer That Simply Keeps Working. With 20 Litres to Play With.

The Cooper Pegler CP3 Classic shares the same fundamental quality as its smaller sibling, the CP15: it does not stop working. Professionals across the UK choose it because it requires minimal maintenance, handles the toughest professional chemicals without complaint, and keeps performing accurately year after year. Furthermore, Spindrift, the UK distributor, regularly services CP3 Classic sprayers that are over 50 years old. That is not coincidence. It is the direct result of a diaphragm pump design with no moving parts exposed to friction, brass components throughout, and a build philosophy that has never prioritised price over quality.

The CP3 brings all of this to a 20-litre tank. For amenity contractors, groundskeepers, landscape professionals, and estate managers who cover large areas daily, that additional capacity translates directly into fewer refills, fewer interruptions, and more time actually spraying. Consequently, it is the natural choice for anyone who finds the CP15 running dry too quickly.

The Pump That Sets It Apart

No Friction. No Wear. No Problem.

The heart of the CP3 Classic is its diaphragm pump, and it is what separates this sprayer from the competition. Pressure is generated through the controlled deformation of a highly flexible diaphragm rather than through direct mechanical contact between moving parts. As a result, friction is essentially eliminated from the pump mechanism. This means the pump resists the fine particles and sediment that rapidly destroy conventional piston pumps, particularly in demanding professional field conditions. Moreover, brass components throughout the pump mechanism add further durability and chemical resistance. Therefore, the pump continues to deliver accurate, consistent performance long after cheaper alternatives have given up.

Why 20 Litres Makes a Real Difference

For many professional operators, the choice between the CP15 and CP3 Classic comes down to one thing: refill frequency. Specifically, the CP3 carries a third more liquid than the CP15. On a large grounds maintenance contract, a highway verge treatment, or a commercial weed control programme, that difference translates directly into productivity. As a result, operators spend more time spraying and less time walking back to the vehicle. In addition, the CP3 is the natural choice when using boom attachments, where liquid consumption rates are higher and the larger tank earns its keep quickly.

Key Features and Benefits

Dual Pressure Control Valve (1 Bar and 3 Bar Settings)

The integrated pressure control valve delivers two fixed working pressures. First, the 1 bar setting suits low-pressure applications such as fungicides and insecticides, where fine, even droplet distribution matters. Second, the 3 bar setting delivers the higher pressure that herbicide application requires, ensuring a consistent flat-fan pattern across the target area. A dedicated switching tool is supplied as standard, so changing between settings in the field takes seconds. For professional operators, furthermore, this precision is not optional. Accurate, repeatable application rates are a regulatory requirement under UK pesticide legislation.

The Cooper Pegler Trigger Assembly

Still the Best Valve on the Market.

Professionals widely regard the Cooper Pegler trigger assembly as the finest available on any knapsack sprayer. Additionally, it fits every lance tube and accessory across the entire Cooper Pegler range, making it a genuinely versatile and future-proof component. The ergonomic composite handle reduces hand fatigue during extended spraying sessions. Furthermore, the lock-on feature allows continuous spraying without maintaining constant trigger pressure, which is a meaningful productivity advantage for operators covering large areas. An integrated filter within the trigger assembly also provides additional protection against blockages at the point closest to the nozzle.

Double Filtration System

Blockages cost time and disrupt consistent spray quality. Accordingly, the CP3 Classic tackles this with a two-stage filtration approach. First, a low-mesh strainer in the filler neck removes debris at the point of filling. Then, a supplementary filter within the trigger assembly provides a second line of defence immediately before the spray reaches the nozzle. As a result, operators experience fewer interruptions and more consistent results throughout the working day.

20-Litre UV-Stabilised Polypropylene Tank

Built to Handle Daily Professional Use.

The transparent tank is rated at 20 litres, with an actual capacity of 25 litres. Cooper Pegler manufactures it from UV-stabilised polypropylene, making it lightweight, chemically resistant, and tough enough for daily outdoor use. The translucent construction also allows operators to monitor liquid levels at a glance without removing the lid. Additionally, the wide 140mm filler neck makes refilling fast and clean, reducing the risk of splashing and operator contamination. A lid with a dedicated seal and integrated air vent prevents both leakage and vacuum formation as the tank empties, ensuring smooth, uninterrupted pump performance from a full tank down to the last litre.

Fibreglass-Reinforced GRP Lance

The 500mm lance is constructed from glass-reinforced plastic, providing the rigidity and strength of a metal lance without the weight or corrosion risk. GRP also offers excellent chemical resistance across the full range of products in common professional use. Brass hose fittings connect the lance to a reinforced high-pressure hose, completing a spray line that is built to last through years of daily handling.

Left or Right-Hand Operation

The reinforced pumping lever adjusts for left or right-hand operation without tools. Any operator can therefore set up the sprayer in seconds, which matters particularly on busy contracting sites where equipment is shared between multiple operators during the working day.

Rapid-Fit Shoulder Harness

The rapid-fit harness uses polyethylene shoulder pads with polyester fibre braiding, providing a practical and hardwearing carrying system for daily professional use. The quick-release fitting also allows the sprayer to be donned and removed rapidly when moving between treatment areas or in and out of vehicles throughout the day.

Full Specifications

What’s in the Box

• Cooper Pegler CP3 Classic 20L knapsack sprayer
• Green anvil/reflex nozzle (AN1.2) for herbicide application
• Yellow hollow cone nozzle (HCX-02) for fungicide and insecticide application
• Pressure setting tool

Accessories and Compatibility

The CP3 Classic works with the complete Cooper Pegler accessories range. Moreover, all lances, nozzles, booms, and fittings are also compatible with the Series 2000 and Evolution families. As a result, contractors running mixed fleets need only one set of spares. Particularly useful accessories for the CP3 include:

• Multi-nozzle spray booms (2, 3, and 4 nozzle configurations) for wider application widths
• Extended telescopic lance tubes for taller vegetation or deep shrub beds
• Spray shields for targeted spot treatment with reduced drift risk
• Flat fan, deflector, and adjustable nozzle options for different applications
• Replacement diaphragms, seals, and full service kits

Ideal Applications

The CP3 Classic suits any situation where a larger tank or higher liquid consumption makes 20 litres more practical than 15. In particular, it excels in the following settings:

• Herbicide application on paths, car parks, highway verges, and hard surfaces
• Weed control across large amenity planting schemes and landscape contracts
• Grounds maintenance on sports pitches, golf courses, parks, and public open spaces
• Fungicide and insecticide treatment on ornamental planting, shrubs, and hedgerows
• Local authority and highways weed control operations
• Estate, farm, and forestry management
• Boom-assisted treatment of large grass areas and planting beds
• Garden use on large properties or for keen gardeners with extensive grounds

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 CP3 Classic is designed and manufactured in compliance with European safety standards for professional spraying equipment. Regular calibration and maintenance in line with National Sprayer Testing Scheme (NSTS) guidelines will therefore ensure accurate, compliant application throughout the sprayer’s working life.

Over 60 Years in the Field. Still the Benchmark.

Cooper Pegler has been manufacturing professional spraying equipment for over 100 years. Specifically, the CP3 Classic traces its lineage directly to the original knapsack developed with ICI Plant Protection in the 1960s. Like all Cooper Pegler products, it is produced in the EXEL Industries factory in France to exacting European standards. Spare parts are additionally guaranteed to be available for a minimum of ten years after any product is discontinued. In a market that regularly sees new entrants make bold claims with modest build quality, the CP3 Classic simply keeps working. Ultimately, if you need a 20-litre knapsack sprayer that stands up to professional daily use, accepts a full range of accessories, and remains fully serviceable a decade from now, the CP3 Classic is the answer.

Not sure the CP3 is right for you? If a 15-litre tank suits your workload better, take a look at the Cooper Pegler CP15 Classic. If you are considering the Berthoud range instead, the Berthoud Cosmos 18 Pro delivers 6 bar pressure and a built-in agitator mixer at a highly competitive price, while the Berthoud Vermorel 1800 is our most ergonomic knapsack for operators on their backs all day.

Need advice on nozzle selection, boom options, or whether the CP3 or CP15 is the right choice for your operation? Contact the Phoenix Amenity Supplies team. We are specialists in professional amenity spraying equipment and happy to help.