API SPEC 4F-2020 pdf download.Specification for Drilling and Well Servicing Structures.
1 Scope This specification states requirements and gives recommendations for suitable steel structures for drilling and well servicing operations in the petroleum industry, provides a uniform method of rating the structures, and provides two product specification levels (PSLs). This specification is applicable to all new steel derricks, masts (including masts with guy lines and service rig masts), substructures, and crown block assemblies with a date of manufacture after the effective date of this specification. Annex A provides standard supplementary requirements (SRs) that apply only if specified by the purchaser. Annex B is an informative annex to assist in an understanding/application of this API specification. Annex C is an informative annex regarding the API Monogram Program and the API Monogram marking requirements. Annex D is an informative annex providing guidelines to assist the purchaser with purchasing equipment manufactured to the requirements in this API document. 2 Normative References The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda) applies. API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in the Gulf of Mexico API Recommended Practice 2A-WSD, Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms—Working Stress Design API Recommended Practice 4G, Recommended Practice for Use and Procedures for Inspection, Maintenance, and Repair of Drilling and Well Servicing Structures API Recommended Practice 9B, Recommended Practice on Application, Care and Use of Wire Rope for Oilfield Service API Specification 8C, Specification for Drilling and Production Hoisting Equipment (PSL 1 and PSL 2) API Specification 9A, Specification for Wire Rope 3 Terms and Definitions For the purposes of this document, the following terms and definitions apply. 3.1 appurtenances All components attached to but not part of the bare drilling structure. 3.2 bare drilling structure The structural members of the drilling structure including crown, water table, and gin pole as applicable. 3.3 clear height Minimum vertical distance. For derrick and mast without guy lines, this means from the top of the working floor to the bottom of the crown block support beams. For mast with guy lines, this means from the top of the working floor to the bottom of the crown block support beams. For service rigs with guy lines, this means from the ground to the bottom of the crown block support beams. 3.4 critical component Component that is necessary to maintain stability of a structure and that resides within the primary load paths of the structure when the structure is loaded under the design loadings of Section 7. 3.5 critical weld Weld that joins critical components. 3.6 crown block assembly The set of components including sheave or block assemblies installed at the top of a derrick or mast to support the hook load. 3.7 date of manufacture Date chosen by the manufacturer occurring between the initiation of manufacture and the delivery to the purchaser. 3.8 derrick Structural tower, of square or rectangular cross section, having members that are latticed or trussed on all four sides. NOTE It may or may not be guyed. 3.9 design load Force or combination of forces that a structure is designed to withstand without exceeding the allowable member strength in any member.
3.10 design reference wind velocity V ref The wind velocity of a 3-second gust at a 1 0 m (33 ft) reference elevation, in knots, for the appropriate return period at the intended drilling location. 3.11 design validation The process of proving a design to demonstrate conformity of the product to design requirements. 3.12 design verification The process of examining the result of design and development output to determine conformity with specified requirements. 3.13 dynamic loading Loading imposed upon a structure as a result of motion. 3.14 erection load Load produced in the mast and its supporting structure during its raising and lowering, or in the substructure during its raising and lowering. 3.15 guide tracks and dollies Equipment used to hold the traveling equipment in correct position relative to the derrick during various operations. NOTE position. A retractable dolly is used move the traveling equipment horizontally between the drilling position and the retracted 3.16 guy line Wire rope with one end attached to the mast assembly and the other end attached to a suitable anchor to provide structural and/or lateral support for a mast under design loading conditions.