This specification covers warping heads used with windlass, winch, and capstan drive units to pull rope on board ships. Warping heads are primarily for use with fiber rope, natural, or synthetic. Warping heads with external ribs or whelps on the barrel, notched flanges, attached storage drums, unfinished drums, or non heat-treated fabrications, are considered special. The size of the warping head shall be identified by the nominal barrel diameter measured at the smallest point of the barrel. These warping heads are furnished in two types: Type I is with a cylindrical barrel which is generally used in but not restricted to horizontal shaft applications and Type II is with a conical barrel which is mounted with the large end of the barrel toward the drive machinery. It is generally used in but not restricted to vertical shaft applications. On the other hand, the warping heads are divided into four grades according to composition: Grade 1 is fabricated from any combination of structural steel plate, pipe, tubing, or steel castings and joined by electric welding; Grade 2 is made from mild to medium strength steel; Grade 3 is fabricated from any combination of steel plate or steel castings and joined by electric welding; and Grade 4 is cast from high strength steel castings. Principal dimensions, tolerances, and strength requirements are discussed.1.1 This specification covers warping heads used with windlass, winch, and capstan drive units to pull rope on board ships. Warping heads are primarily for use with fiber rope, natural, or synthetic.1.2 Warping heads with external ribs or whelps on the barrel, notched flanges, attached storage drums, unfinished drums, or non heat-treated fabrications, are considered special and are permitted within the scope of this specification when fully described under special ordering information.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
定价: 515元 加购物车
4.1 These test methods can be used to determine the effects of head and cone materials, design variables, manufacturing, and other conditions on the cyclic load-carrying ability of modular femoral heads mounted on the cones of femoral stem prostheses.4.2 The loading of modular femoral heads in vivo will, in general, differ from the loading defined in these methods. The results obtained here cannot be used to directly predict in-vivo performance. However, these methods are designed to allow for comparisons between the fatigue performance of different ceramic modular femoral head designs, when tested under similar conditions.4.3 These test methods may use actual femoral prostheses or neck-cone models of simplified geometry with the same geometrical and material characteristics as in the implants. In either case, the matching metallic cone region of the test specimen selected shall be of the same material, tolerances, and finish as the final femoral stem prosthesis.4.4 In the fatigue test methods, it is recognized that actual loading in vivo is quite varied, and that no one set of experimental conditions can encompass all possible variations. Thus, the test methods included here represent a simplified model for the purposes of comparisons between designs and materials. These test methods are intended to be performed in physiological solution.4.5 The test data may yield valuable information about the relative strengths of different head and cone designs.1.1 These test methods cover the evaluation of the cyclic fatigue strength of ceramic modular femoral heads, mounted on a cone as used on the femoral stem of the total hip arthroplasty.1.2 These test methods were primarily developed for evaluation of ceramic (Specification F603, ISO 6474-1, ISO 6474-2, ISO 13356) head designs on metal cones but may have application to other materials.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
定价: 590元 加购物车