Most modern air-water portable fire extinguishers and an air-foam fire extinguishers can be recharged on site after use in accordance with the manufacturers recommendations.
These fire extinguishers are fitted with a type of pneumatic valve called a schrader valve to enable a competent person to pressurise the fire extinguisher after its contents has been replaced.
A schrader valve is a type of pneumatic valve that is used for all types of car, truck, motorcycle and some bicycles to inflate the vehicle tires. A schrader is also a popular type of valve used by industry for other applications where a pressurised gas is required to pressurise or inflate a container or vessel.