Oxygen Free Nitrogen (OFN) cylinders are filled to 200 bar pressure (at 15°C) and are therefore perfect for a variety of service applications such as: strength and pressure testing systems (preventing leakage of expensive refrigerants and unnecessary rework, saving you time and improving end user satisfaction), cleaning condenser coils (which improves system efficiency), Harp Nitrogen cylinders come with a 3 month free rental period (contact us for further details).