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定价: 481元 / 折扣价: 409

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定价: 481元 / 折扣价: 409

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3.1 This test method is designed as an inspection or acceptance test of new bare soft square and rectangular wire intended for subsequent fabrication into magnet wire.NOTE 1: Since the applied unit stress and the time of application are constant for all wire sizes, the test enables comparisons of stiffness to be made between wires of the same or different size on the basis of the permanent elongation resulting from the application of a low unit stress.1.1 This test method, known as the low-stress elongation (LSE) test, covers the procedure for determining the stiffness of bare soft square and rectangular copper and aluminum wire in terms of the permanent elongation resulting from the application of a tensile stress.1.2 The SI values for the mass of the specimen are regarded as the standard. For all other properties, the inch-pound values are to be regarded as standard and the SI units may be approximate.1.3 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 / 折扣价: 438 加购物车

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AS 1746-1991 (R2016) Conductors - Bare overhead - Hard-drawn copper 现行 发布日期 :  1970-01-01 实施日期 : 

定价: 345元 / 折扣价: 294

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5.1 Manufacturers of thermal insulation for valves typically express the performance of their products in charts and tables showing heat loss per valve. These data are presented for both bare and insulated valves of different pipe sizes, ANSI classes, insulation types, insulation thicknesses, and service temperatures. Additional information on effects of wind velocity, jacket emittance, bare valve emittance, and ambient conditions are also required to properly select an insulation system. Due to the infinite combination of pipe sizes, ANSI classes, insulation types and thicknesses, service temperatures, insulation cover geometries, surface emittance values, and ambient conditions, it is not possible to publish data for each possible case.5.2 Users of thermal insulation for piping systems faced with the problem of designing large systems of insulated piping, encounter substantial engineering costs to obtain the required thermal information. This cost can be substantially reduced by both the use of accurate engineering data tables, or by the use of available computer analysis tools, or both.5.3 The use of this practice by the manufacturer, contractor, and users of thermal insulation for valves and flanges will provide standardized engineering data of sufficient accuracy and consistency for predicting the savings in heating energy use by insulating bare valves and flanges.5.4 Computers are now readily available to most producers and consumers of thermal insulation to permit use of this practice.5.5 The computer program in Practice C680 has been developed to calculate the heat loss per unit length, or per unit surface area, of both bare and insulated pipe. With values for bare valve or flange surface areas, heat loss can be estimated. By estimating the outer insulation surface area from an insulation manufacturer's or contractor's drawings, the heat loss from the insulation surface can likewise be calculated by taking the product of heat loss per unit area (from programs conforming to Practice C680) and the valve or flange insulation surface area. The area of the uninsulated surfaces also will need to be considered.5.6 The use of this practice requires that the valve or flange insulation system meets either Specification C1695 for removeable/reuseable or the Adjunct to Practice C4503 for insulation fabricated from rigid board and pipe insulation.1.1 The mathematical methods included in this practice provide a calculational procedure for estimating heat loss or heat savings when thermal insulation is added to bare valves and flanges.1.2 Questions of applicability to real systems should be resolved by qualified personnel familiar with insulation systems design and analysis.1.3 Estimated accuracy is limited by the following:1.3.1 The range and quality of the physical property data for the insulation materials and system,1.3.2 The accuracy of the methodology used in calculation of the bare valve and insulation surface areas, and the quality of workmanship, fabrication, and installation.1.4 This procedure is considered applicable both for conventional-type insulation systems and for removable/reuseable covers. In both cases, for purposes of heat transfer calculations, the insulation system is assumed to be homogenous.1.5 This practice does not intend to establish the criteria required in the design of the equipment over which thermal insulation is used, nor does this practice establish or recommend the applicability of thermal insulation over all surfaces.1.6 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.1.7 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 and health practices and determine the applicability of regulatory limitations prior to use.

定价: 590元 / 折扣价: 502 加购物车

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This specification covers the chemical and mechanical requirements of hexagon and square-head zinc-coated steel bolts and atmospheric corrosion-resistant bolts for use in the construction of transmission towers, substations, and similar steel structures. The following types of bolts are: Type 0 includes hot-dip zinc-coated bolts made of low or medium carbon steel, Type 1 includes hot-dip zinc-coated bolts made of medium carbon steel, quenched and tempered, Type 2, and Type 3 includes bare, quenched, and tempered bolts made of weathering steel. Steel for the manufacture of bolts shall be made by any of the following processes: open-hearth, electric-furnace, or basic-oxygen. Type 1 bolts produced from medium carbon steel shall be quenched in a liquid medium from above the austenizing temperature. Type 1 bolts produced from medium carbon steel to which chromium, nickel, molybdenum, or boron were intentionally added shall be quenched only in oil from above the austenitizing temperature. Type 3 bolts shall be quenched only in oil from above the austenitizing temperature. Cold-headed Type 0 bolts shall be stress relief annealed before zinc coating to remove cold work effects such that the hardness measured anywhere on the surface or through the cross-section shall meet the requirement specified. Different tests shall be conducted in order to determine the following mechanical properties of bolts: hardness, tensile strength, and shear strength.1.1 This specification covers the chemical and mechanical requirements of hexagon and square-head zinc-coated steel bolts and atmospheric corrosion-resistant bolts, in nominal thread diameters of 1/2 , 5/8 , 3/4 , 7/8 and 1 in. for use in the construction of transmission towers, substations, and similar steel structures. The various types of bolts covered in this specification are:1.1.1 Type 0—Hot-dip zinc-coated bolts made of low or medium carbon steel.1.1.2 Type 1—Hot-dip zinc-coated bolts made of medium carbon steel, quenched and tempered.1.1.3 Type 2—Withdrawn in 2005.1.1.4 Type 3—Bare (uncoated), quenched and tempered bolts made of weathering steel.1.2 Annex A1 of this specification covers hot-dip zinc-coated steel ladder bolts, step bolts, and support-equipment bolts.1.3 Nuts and washers that are supplied under this specification that are hot-dip zinc coated shall be in accordance with 4.4.1.4 Terms used in this specification are defined in Terminology F1789.1.5 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.1.6 The following safety hazards caveat pertains only to the test methods portion, Section 11, of this specification. 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.1.7 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 / 折扣价: 502 加购物车

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定价: 481元 / 折扣价: 409

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