Section R. 460.20102 - DefinitionsRule 102. As used in these rules:
(a) "Commission" means the Michigan public service commission.(b) "Corrosion" means the destruction or deterioration of a material, usually a metal, by an electrochemical process, due to a reaction with the material's environment.(c) "Customer" means a person or company who purchases gas from a distributor for the person's or company's own use or for the use of a tenant, or both.(d) "Hoop stress" means the stress in a pipe wall which acts circumferentially in a plane perpendicular to the longitudinal axis of the pipe and which is produced by the pressure of the fluid in the pipe.(e) "Leak" means the unintentional escape of gas from a pipeline facility or a customer's facility.(f) "Leakage survey" means a systematic inspection that is made to locate leaks in a gas pipeline.(g) "Pressure" means gauge pressure, unless otherwise stated, expressed in pounds per square inch above atmospheric pressure and is abbreviated "psig."(h) "Sour gas" means gas containing a concentration of hydrogen sulfide (H2S) greater than or equal to 300 parts per million (ppm.).(i) "System" means all pipeline facilities used by a particular operator in the transportation of gas, including all of the following:(C) Other appurtenances connected to line pipe.(E) Fabricated assemblies associated with compressor units.(I) Fabricated assemblies in metering and delivery stations.(j) "Vault" means an underground structure that may be entered and that is designed to contain piping and piping components, such as valves and pressure regulators. The terms "vault"and "pit" are used interchangeably in these rules.Mich. Admin. Code R. 460.20102