1.1 Scope 1.1.1 This standard covers the minimum requirements for special purpose steam turbines for petroleum, chemical, and gas industry services. These requirements include basic design, materials, and related lube-oil systems, controls, and auxiliary equipment. Note: A bullet (--) at the beginning of a paragraph indicates that either a decision is required or further information is to be provided by the purchaser. This information should be indicated on the data sheets (see Appendix A); otherwise it should be stated in the quotation request or in the order. 1.1.2 Steam turbines are classified general-purpose or special purpose according to service requirements as described in 1.1.2.1 and 1.1.2.2. 1.1.2.1 General-purpose turbines are those horizontal or vertical turbines used to drive equipment that is usually spared, is relatively small in size (power), or is in noncritical service. They are intended for applications where conditions will not exceed 48 bar gauge (700 pounds per square inch gauge) pressure or 400 °C (750 °C) inlet temperature, or both, and where speed will not exceed 6000 revolutions per minute. Requirements for general purpose turbines are defined in API Standard 611. 1.1.2.2 Special purpose turbines are those horizontal turbines used to drive equipment that is usually not spared, is relatively large in size (power), or is in critical service. This category is not limited by steam conditions or turbine speed.