Z341-93

1.1 This Standard covers the minimum design, construction, operation, abandonment, and safety aspects of hydrocarbon storage in underground formations and associated equipment. Equipment shall include all subsurface process equipment, the wellhead, and all safety equipment related to the storage facilities, wells, and wellheads. Hydrocarbons shall include crude oil, diesel, natural gas, methane, ethane, propane, butane, and other hydrocarbons by themselves or in mixtures. 1.2 The scope of this Standard is shown in Figure 1.1. 1.3 This Standard does not apply to (a) underground storage facilities for gases or fluids other than hydrocarbons, ie, storage facilities used for air storage, unless these fluids are used specifically for the displacement of stored hydrocarbons; (b) underground storage facilities used for purposes other than for storing hydrocarbons, ie, reaction chambers, waste disposal; (c) underground storage in overburden materials involving the use of tanks, ie, gasoline tanks; (d) design and fabrication of pressure vessels that are covered by pressure vessel codes; (e) heat exchangers, pumps, compressors, and piping in processing plant facilities, manufacturing plants, or industrial plants that are covered by appropriate codes; or (f) gathering lines, flow lines metering, compressors, and associated surface equipment beyond the first emergency shutdown or block valve. 1.4 It is not the intent of this Standard to prevent the development of new equipment or practices, or to prescribe how such innovations should be handled. 1.5 Where any requirements of this Standard are at variance with the requirements of other Standards or Codes incorporated by reference into this Standard, the requirements of this Standard shall govern. 1.6 The requirements of this Standard shall not be applied retroactively to existing installations and installations under construction at the time of its approval but shall apply to the extension, replacement, maintenance, and upgrading of such installations.