ABSTRACT
Pressure regulators – devices that reduce a higher variable inlet pressure to a constant lower outlet pressure. The different types of pressure regulators classified as follows. Direct – where the cylinder pressure opens the valve; and indirect – where a spring opens the valve in response to falling outlet pressure. Two-stage – where the input of one is the output of the other, this reduces wear on the diaphragm and reduces pressure fluctuations in high gas flows; and Slave – where the output of one valve is dependent on the output of another. Gas cylinders are used to store gases and vapours at high pressures. These pressures vary according to the type of gas or vapour used the cylinder content and temperature. The temperature and cylinder content will in turn vary as the gas or vapour is used. If unregulated this would lead to a variable flow of gas or vapour to the patient.
