Haskel portable charging units are durable, compact and lightweight. They provide an infinitely adjustable pressure source for pressure testing with nitrogen gas and ensure the optimum use of commercially bottled nitrogen gas down to a residual pressure of 7 bar. Charged gas pressures up to 500 bar are standard, but higher pressures can be achieved if required. Powered by compressed gas from a compressor or gas cylinder, they are suitable for operation in any location.