定价： 646元 / 折扣价： 550 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

4.1 This test method is often used to determine bulk density values that are necessary for use for many methods of selecting proportions for concrete mixtures.4.2 The bulk density also may be used for determining mass/volume relationships for conversions in purchase agreements. However, the relationship between degree of compaction of aggregates in a hauling unit or stockpile and that achieved in this test method is unknown. Further, aggregates in hauling units and stockpiles usually contain absorbed and surface moisture (the latter affecting bulking), while this test method determines the bulk density on a dry basis.4.3 A procedure is included for computing the percentage of voids between the aggregate particles based on the bulk density determined by this test method.1.1 This test method covers the determination of bulk density (“unit weight”) of aggregate in a compacted or loose condition, and calculated voids between particles in fine, coarse, or mixed aggregates based on the same determination. This test method is applicable to aggregates not exceeding 125 mm [5 in.] in nominal maximum size.NOTE 1: Unit weight is the traditional terminology used to describe the property determined by this test method, which is weight per unit volume (more correctly, mass per unit volume or density).1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard, as appropriate for a specification with which this test method is used. An exception is with regard to sieve sizes and nominal size of aggregate, in which the SI values are the standard as stated in Specification E11. Within the text, inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 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.1.4 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： 590元 / 折扣价： 502 元 加购物车

4.1 This guide provides a method to determine the thermal performance of low-density blanket-type insulation. It may be used for the purposes of quality assurance, certification, or research.4.2 The thermal resistance of low-density insulation depends significantly on the density, the thickness, and thermal conductivity. Typical low-density, mineral-fiber insulation for buildings may vary in density from one specimen to the next.4.3 Thermal tests are time-consuming in comparison with density and thickness measurements. Low-density insulation material is produced in large quantities. A typical lot would be a truckload or the amount necessary to insulate a house.4.4 The relatively low unit cost of this product and the relatively high cost of thermal resistance testing makes it cost-effective to test only a small percentage of the product area. It is recommended that there be a determination of the density that is representative of a lot by the measurement of the average density of a statistically representative sampling.4.5 A fewer number of thermal measurements are then made to determine the apparent thermal conductivity at the previously determined representative density. The essential significance of this guide is that a large lot of variable material is best characterized by: (a) determining the representative density, and by (b) determining the thermal property at this representative density with a small number of thermal measurements.4.6 Building insulation products are commonly manufactured in thicknesses ranging from 19 to 330 mm (0.75 to 13 in.) inclusive. Experimental work has verified that there is a dependence of λapp on thickness for some low density materials.4.7 The upper limit of test thickness for specimens evaluated using Test Methods C177, C518, and C1114 is established based upon the apparatus design, overall dimensions, expected thermal resistivity level and desired target accuracy. The testing organization is responsible for applying these restrictions when evaluating a product to ensure that the results meet applicable product labels and any existing regulatory requirements (2).4.8 Extrapolation of the apparent thermal conductivity or the thermal resistance beyond the ranges of thickness or density of products tested is not valid.1.1 This guide describes the calculation and interpolation of a thermal resistance value for low-density blanket-type insulation material at a particular density and thickness having been selected as representative of the product. It requires measured values of this average density and thickness, as well as apparent thermal conductivity values determined by either Test Method C177, C518, or C1114.1.2 This guide applies to a density range for mineral-fiber material of roughly 6.4 to 48 kg/m3 (0.4 to 3.0 lb/ft3). It is primarily intended to apply to low-density, mineral-fiber mass insulation batts and blankets, exclusive of any membrane facings. Apparent thermal conductivity data for these products are commonly reported at a mean temperature of 23.9°C (75°F) and a hot-to-cold plate temperature difference of 27.8°C (50°F) or 22.2°C (40°F).1.3 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 元 加购物车

This specification covers the requirements and test methods for high-density polyethylene (PE) materials, line pipes, and fittings used in pressure or non-pressure oil and gas producing applications to convey fluids such as oil, dry or wet gas, multiphase fluids, and non-potable oilfield water. This specification does not apply to pipes for gas distribution applications. PE material compounds suitable for use in the manufacture of pipes and fittings under this specification shall adhere to values of the following properties: density (natural base resin), melt index, flexural modulus, tensile strength at yield, SCG resistance, hydrostatic strength, color and UV stabilization, hydrostatic design stress, and hydrostatic design basis. The line pipes shall meet specific requirements as to workmanship, dimensions (outside diameter, toe-in, outside surface irregularity, ovality, wall thickness, and special sizes), inside surface ductility, tensile elongation, bendback resistance, elevated temperature sustained pressure, short-term strength and pressurization, apparent tensile strength at yield, and carbon black content. And conversely, PE fittings shall be manufactured in accordance with their intended use with correspondingly sized PE line pipes, as follows: socket fusion fittings, butt fusion fittings, electrofusion fittings, fabricated fittings, and transition fittings.1.1 This specification covers requirements and test methods for high-density polyethylene (PE) materials, pipe and fittings for pressure or non-pressure oil and gas producing applications to convey fluids such as oil, dry or wet gas, multiphase fluids, and non-potable oilfield water. This specification does not cover pipe for gas distribution applications.1.1.1 For the purposes of this specification, high-density polyethylene material is Specification D3350 density cell classification 3 or higher. This specification does not cover materials having Specification D3350 density cell classification less than 3 such as medium or low density polyethylene materials.1.1.2 See Specification D2513 for polyethylene pipe and fittings intended for use in the distribution of natural gas, or for use with liquefied petroleum gas.1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 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.1.4 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： 646元 / 折扣价： 550 元 加购物车

5.1 It is important for rubber compounders to know the extent of devulcanization a rubber might have undergone during recycling. It allows the compounder to determine if more curing agents are needed during mixing of devulcanized rubber when used either as partial replacement or stand alone.1.1 This test method covers the procedure for determining percent devulcanization from crosslink density measurements of devulcanized rubber and control crumb rubber in the laboratory. Percent devulcanization is a quantitative determination.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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.1.4 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 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

1.1 This test method covers the measurement of apparent density in pounds in air per U.S. gallon at convenient temperatures using a hydrometer, and reporting at any specified atmospheric temperature. 1.2 The following applies to all specified limits in this test method: for purposes of determining conformance with this test method, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E 29. 1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 7 and Note 3.

定价： 0元 / 折扣价： 0 元

4.1 The tex system has been approved for general use by the International Organization for Standardization, Technical Committee 38 on Textiles (ISO/TC 38), which has also recommended a list of rounded tex numbers for use with fibers and all types of yarns. Conversion tables showing the rounded tex numbers corresponding to various numbers in different traditional systems are given in Tables D2260 and ISO 2947.4.2 The tex system for designation of the linear density of fibers and yarns is a direct system based on mass per unit length, M/L, and employs metric units of length and mass. The tex unit, grams per kilometre (1000 m) has been approved by ISO/TC 38 for use with all fibers and all types of yarn. The committee has also approved the use of kilotex and decatex numbers for coarse structures and decitex and millitex numbers for fibers.4.3 The tex system relates to the property commonly associated with coarseness, or inverse fineness of a yarn because the tex numbers increase with an increase in the size or mass per unit length of the yarn. The tex system is intended for use by all branches of the textile industry, in all countries, for yarns made from all types of fibers or mixtures of fibers.1.1 This practice covers the use of the tex system to designate the linear density (number, or count) of fibers and of yarns made from any type of fiber or combination of fibers. It is also applicable to other textile materials, including yarn intermediates (slivers, rovings, tops, and so forth), single or plied yarns, cords, and threads.NOTE 1: The mass per unit length concept of linear density is applicable to any material which has a high ratio of length to cross section.1.2 Conversion factors for various indirect and direct yarn numbers to exact tex equivalents can be found in Standard Tables D2260.1.3 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.1.4 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 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车