The Single Area Valve Service Units (AVSUs) are manufactured under BS EN 13485 Medical Devices: Quality Management Systems and Medical Device Directive 93/42/EEC. They provide a local gas isolation facility for use during normal installation and maintenance or in the event of an emergency. They are built in accordance with the HTM02-01, C11 and BS EN 18082 standards and are suitable for Oxygen, Nitrous Oxide, Oxy Nitrous Oxide, MA4, MA7, CO2 and Vacuum (other gases on request).