Gas piping systems for welding and cutting should be manufactured and installed in accordance with National Fire Protection Association (NFPA) standards, such as NFPA 51 Oxygen-Fuel Gas Systems for Welding and Cutting, and NFPA 50 Bulk Oxygen System at Consumer Sites. Other standards that should be consulted are Compressed Gas Association (CGA) CGA E-1 Regulator Connection Standards and CGA E-2 Standard Hose Connection Specification. In addition, refer to American National Standards Institute (ANSI) standard ANSI 249.1 Safety in Welding, Cutting and Allied Processes for safe practices in the use of gases when welding and cutting.