定价： 481元 / 折扣价： 409 元 加购物车

5.1 Procedure A is designed to produce moisture diffusion material property data that may be used as follows:5.1.1 To determine approximate exposure times for coupon conditioning in Procedures B-E, Y, and Z;5.1.2 As input to moisture prediction analysis computer codes; or5.1.3 For making qualitative decisions on material selection or performance under environmental exposure to various forms of moisture.5.2 Procedures B-E are designed to condition test coupons to a specified environmental condition or equilibrium state prior to other material property testing (including, but not limited to, mechanical testing).5.3 Procedures Y-Z are designed to determine the loss of moisture content due to removal of a test coupon from the conditioning chamber (such as for strain gauge bonding) or due to heating of the test coupon prior to and during mechanical loading.5.4 A single pair of tests on thin and thick specimens using Procedure A provides the moisture diffusivity constant, Dz, and the moisture equilibrium content, Mm, at the given moisture exposure level and temperature. Multiple tests at differing temperatures are required to establish the dependence of Dz on temperature. Multiple tests at differing moisture exposure levels are required to establish the dependence of Mm on moisture exposure level.NOTE 1: For many polymer matrix composites, the moisture diffusivity is usually only weakly related to relative humidity and is often assumed to be a function only of temperature, usually following an Arrhenius-type exponential relation with inverse absolute temperature. For many of these materials, moisture equilibrium content is only weakly related to temperature and is usually assumed to be a function only of relative humidity (1).5.5 Vapor-exposure testing shall be used to condition the specimen when the in-service environmental condition is a vapor such as humid air. Immersion in a liquid bath should be used to simulate vapor exposure only when apparent absorption properties are desired for qualitative purposes. Properties determined in the latter manner shall be reported as apparent properties.NOTE 2: For many polymer matrix composites, the moisture absorption properties under atmospheric humid conditions are generally not equivalent to exposure either to liquid immersion or to pressurized steam. These latter environments may have different material diffusion characteristics.1.1 This test method covers a procedure for the determination of moisture absorption or desorption properties in the through-the-thickness direction for single-phase Fickian solid materials in flat or curved panel form. Also covered are procedures for conditioning test coupons prior to use in other test methods; either to an essentially moisture-free state, to equilibrium in a standard laboratory atmosphere environment, or to equilibrium in a non-laboratory environment. Also included are procedures for determining the moisture loss during elevated temperature testing, as well as moisture loss resulting from thermal exposure after removal from the conditioning environment, such as during strain gauge bonding. While intended primarily for laminated polymer matrix composite materials, these procedures are also applicable to other materials that satisfy the assumptions of 1.2.1.2 The calculation of the through-the-thickness moisture diffusivity constant in Procedure A assumes a single-phase Fickian material with constant moisture absorption properties through the thickness of the specimen. The validity of the equations used in Procedure A for evaluating the moisture diffusivity constant in a material of previously unknown moisture absorption behavior is uncertain prior to the test, as the test results themselves determine if the material follows the single-phase Fickian diffusion model. A reinforced polymer matrix composite material tested below its glass-transition temperature typically meets this requirement, although two-phase matrices such as toughened epoxies may require a multi-phase moisture absorption model. While the test procedures themselves may be used for multi-phase materials, the calculations used to determine the moisture diffusivity constant in Procedure A are applicable only to single-phase materials. Other examples of materials and test conditions that may not meet the requirements are discussed in Section 6.1.3 The evaluation by Procedure A of the moisture equilibrium content material property does not assume, and is therefore not limited to, single-phase Fickian diffusion behavior.1.4 The procedures used by this test method may be performed, and the resulting data reduced, by suitable automatic equipment.1.5 This test method is consistent with the recommendations of CMH-17 Rev G (1),2 which describes the desirable attributes of a conditioning and moisture property determination procedure.1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.6.1 Within the text, the inch-pound units are shown in brackets.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.8 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 This method for investigating creep rupture of FRP bars is intended for use in laboratory tests in which the principal variable is the size or type of FRP bars, magnitude of applied force, and duration of force application. Unlike steel reinforcing bars or prestressing tendons subjected to significant sustained stress, creep rupture of FRP bars may take place below the static tensile strength. Therefore, the creep rupture strength is an important factor when determining acceptable stress levels in FRP bars used as reinforcement or tendons in concrete members designed to resist sustained loads. Creep rupture strength varies according to the type of FRP bars used.5.2 This test method measures the creep rupture time of FRP bars under a given set of controlled environmental conditions and force ratios.5.3 This test method is intended to determine the creep rupture data for material specifications, research and development, quality assurance, and structural design and analysis. The primary test result is the million-hour creep rupture capacity of the specimen.5.4 Creep properties of reinforced, post-tensioned, or prestressed concrete structures are important to be considered in design. For FRP bars used as reinforcing bars or tendons, the creep rupture shall be measured according to the method given herein.1.1 This test method outlines requirements for tensile creep rupture testing of fiber reinforced polymer matrix (FRP) composite bars commonly used as tensile elements in reinforced, prestressed, or post-tensioned concrete.1.2 Data obtained from this test method are used in design of FRP reinforcements under sustained loading. The procedure for calculating the one-million hour creep-rupture capacity is provided in Annex A1.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the 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 / 折扣价： 502 元 加购物车

1.1 This specification covers a coextruded polyethylene composite pressure pipe with a butt welded aluminum tube reinforcement between the inner and outer layers. The inner and outer polyethylene layers are bonded to the aluminum tube by a melt adhesive. Included is a system of nomenclature for the polyethylene-aluminum-polyethylene of raised temperature (PE-RT/AL/PE-RT) pipes, the requirements and test methods for materials, the dimensions and strengths of the component tubes and finished pipe, adhesion tests, and the burst and sustained pressure performance. Also given are the requirements and methods of marking. The pipe covered by this specification is intended for use in air conditioning and refrigeration (ACR) line set systems.1.2 This specification relates only to composite pipes incorporating a butt welded aluminum tube having both internal and external polyethylene layers. The welded aluminum tube is capable of sustaining internal pressures. Pipes consisting of metallic layers not butt welded together and plastic layers other than polyethylene are outside the scope of this specification.1.3 The dimensions in this specification are ID controlled to match that of ACR Copper Tube so that the flowrate and volume remains the same on a size-for-size basis.1.4 Specifications for fittings for use with pipe meeting the requirements of this specification are given in Annex A1.1.5 This specification excludes crosslinked polyethylene-aluminum-crosslinked polyethylene pipes (see Specification F1281).1.6 This specification tests the pipe for service at 60 °C ± 2 °C (140 °F ± 3 °F) or 82 °C ± 2 °C (180 °F ± 3 °F).1.7 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.8 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.1.9 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

1.1 This guide describes the specification and re-construction of in-situ pipelines and conduits 2 in. to 63 in. (50 mm to 1600 mm) diameter) by the pulled-in-place installation, into an existing conduit, of circular, radially reduced, Shape-Memory-Polymer Tubular (SMPT) that after installation, re-expands (by “memory”) to press against the ID of the host pipe, thus coupling the interior pipe, by friction fit, as reinforcement to the host pipe. The added SMPT pipe wall restores leak tightness and adds its strength to the host pipe (Dual-Wall Composite-Pipe). It becomes a continuous compressed-fit dual-wall pipeline. Depending upon the SMPT compound used, the re-constructed pipelines or conduits are suitable for pressure and nonpressure pipeline applications such as process piping, raw and treated water transmission, water pipe systems, forced-mains, industrial and oil-patch gathering and transmission pipelines, sanitary sewers, storm sewers, and culverts.NOTE 1: This standard guide covers circular SMPT tubulars which are radially reduced by mechanical means at the time of installation. This guide does not address “liners” that at the time of manufacture are deformed (folded) into U-shape, C-shape, H-shape, or other such configurations. This guide refers to dual-wall meaning two layers of pipe co-joined in the field, which is different from dual-wall factory-made co-extruded pipe or corrugated pipe. This guide does not provide a complete design basis covering the many variables required for design and construction of this field fabricated product; the advice of professional contractors and/or registered professional engineers may be incorporated as an adjunct to this guide.1.2 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.NOTE 2: There are no ISO standards covering the primary subject matter of this guide.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

5.1 Refer to Guide D8509.1.1 This test method determines the open-hole tensile strength of multidirectional polymer matrix composite laminates reinforced by high-modulus fibers. The composite material forms are limited to continuous-fiber or discontinuous-fiber (tape or fabric, or both) reinforced composites in which the laminate is balanced and symmetric with respect to the test direction. The range of acceptable test laminates and thicknesses are described in 8.2.1.1.2 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.1.2.1 Within the text the inch-pound units are shown in brackets.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

5.1 This practice is applicable to sampling liquid wastes and other stratified liquids. The COLIWASA is used to obtain a vertical column of liquid representing an accurate cross section of the sampled material. To obtain a representative sample of stratified liquids, the COLIWASA should be open at both ends so that material flows through it as it is slowly lowered to the desired sampling depth. The COLIWASA must not be lowered with the stopper in place. Opening the stopper after the tube is submerged will cause material to flow in from the bottom layer only, resulting in gross over-representation of that layer.5.2 This practice is to be used by personnel acquiring samples.5.3 This practice should be used in conjunction with Guide D4687 which covers sampling plans, safety, QA, preservation, decontamination, labeling, and chain-of-custody procedures; Practice D5088 which covers decontamination of field equipment used at waste sites; Practice D5283 which covers project specifications and practices for environmental field operations; and Practice D5743 which covers drum sampling.1.1 This practice describes the procedure for sampling liquids with the composite liquid waste sampler, or “COLIWASA.” The COLIWASA is an appropriate device for obtaining a representative sample from stratified or unstratified liquids. Its most common use is for sampling containerized liquids, such as tanks, barrels, and drums. It may also be used for pools and other open bodies of stagnant liquid.NOTE 1: A limitation of the COLIWASA is that the stopper mechanism may not allow collection of approximately the bottom 2.54 cm (1 in.) of material, depending on construction of the stopper.1.2 The COLIWASA should not be used to sample flowing or moving liquids.1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026. Reporting of test results in units other than SI shall not be regarded as nonconformance with 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： 515元 / 折扣价： 438 元 加购物车

1.1 These definitions cover generic terms, including terms of commercial importance, that appear in one or more standards on composites containing high-modulus (greater than 20 GPa (3 × 10 6 psi)) fibers.1.2 The definitions cover, in most cases, special meanings used in the composites industry. No attempt has been made to include common meanings of the same terms as used outside the composites industry.1.3 Definitions included have, in general, been approved as 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： 590元 / 折扣价： 502 元 加购物车

This specification covers composite corrugated steel pipe, intended for uses such as storm water drainage, sanitary sewers, underdrains, construction of culverts, and similar uses. The composite material used in fabrication of the pipe consists of a three-layer polymer protective coating on both sides of a steel sheet core. The composite corrugated steel pipe covered by this specification is classified as Type IC and Type ICS. Type IC pipe shall be fabricated with helical corrugations and a continuous lock seam extending helically from end to end of each length of pipe. Type ICS shall be fabricated with helical corrugations and a continuous helical lock seam extending from end to end of each length of pipe, and with a smooth high-density polyethylene liner thermally bonded to the pipe polymer coating at each interior corrugation crest over the length of the pipe. Types IC and ICS pipe shall conform to the pipe dimensions and sheet thickness. Field joints for each type of composite corrugated steel pipe shall maintain pipe alignment during construction and prevent infiltration of fill material during the life of the installation. The following types of coupling systems shall be permitted: flange type; bell and spigot type; band type with annular corrugations; flat band type; and smooth sleeve type. Specimens cut from production pipe normal to and across the lock seam shall develop the specified tensile strength.1.1 This specification covers composite corrugated steel pipe, intended for uses such as storm water drainage, sanitary sewers, underdrains, construction of culverts, and similar uses. The composite material used in fabrication of the pipe consists of a three-layer polymer protective coating on both sides of a steel sheet core. The three layers consist of an inner layer of fusion-bonded epoxy on the steel surface, an intermediate layer of polyethylene adhesive, and an outer layer of high-density polyethylene.1.2 The three-layer polymer coating protects the base metal against corrosion or abrasion, or both. Severe environments are likely to cause corrosion problems to accessory items such as coupling band hardware unless supplemental protection is provided. Additional protection for composite steel pipe is available by use of coatings applied after fabrication of the pipe as described in Specification A849.1.3 This specification does not include requirements for bedding, backfill, or the relationship between earth cover load and sheet thickness of the pipe. Experience with drainage products has shown that successful performance depends upon the proper selection of corrugation profile, sheet thickness, type of bedding and backfill, controlled manufacture in the plant, and care in installation. The installation procedure is described in Practice A798/A798M.1.4 This specification is applicable to orders in either inch-pound units as A1042, or in SI units as A1042M. Inch-pound units and SI units are not necessarily equivalent. SI units are shown in brackets in the text for clarity, but they are the applicable values when the material is ordered to A1042M.1.5 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 requirements prior to use.

定价： 0元 / 折扣价： 0 元

5.1 This shear test is designed to produce shear property data for material specifications, research and development, quality assurance, and structural design and analysis. Either in-plane or interlaminar shear properties may be evaluated, depending upon the orientation of the material coordinate system relative to the loading axis. Factors that influence the shear response and should therefore be reported include: material, methods of material preparation and lay-up, specimen stacking sequence, specimen preparation, specimen conditioning, environment of testing, specimen alignment and gripping, speed of testing, time at temperature, void content, and volume percent reinforcement.5.2 In anisotropic materials, properties may be obtained in any of the six possible shear planes by orienting the testing plane of the specimen with the desired material plane (1-2 or 2-1, 1-3 or 3-1, 2-3 or 3-2). Only a single shear plane may be evaluated for any given specimen. Properties, in the test direction, which may be obtained from this test method, include the following:5.2.1 Shear stress versus engineering shear strain response,5.2.2 Ultimate shear strength,5.2.3 Ultimate engineering shear strain, and5.2.4 Shear chord modulus of elasticity.1.1 This test method covers the determination of the shear properties of high-modulus fiber-reinforced composite materials by clamping the ends of a V-notched specimen between two pairs of loading rails. When loaded in tension, the rails introduce shear forces into the specimen through the specimen faces. In comparison, the specimen of Test Method D5379/D5379M is loaded through its top and bottom edges. Face loading allows higher shear forces to be applied to the specimen, if required. Additionally, the present test method utilizes a specimen with a larger gage section than the V-notched specimen of Test Method D5379/D5379M. In both test methods, the use of a V-notched specimen increases the gage section shear stresses in relation to the shear stresses in the vicinity of the grips, thus localizing the failure within the gage section while causing the shear stress distribution to be more uniform than in a specimen without notches. In comparison, Test Method D4255/D4255M utilizes an unnotched specimen clamped between two pairs of loading rails that are loaded in tension. Also, in contrast to Test Method D4255/D4255M, the present test method provides specimen gripping without the need for holes in the specimen.The composite materials are limited to continuous-fiber or discontinuous-fiber-reinforced composites in the following material forms:1.1.1 Laminates composed only of unidirectional fibrous laminae, with the fiber direction oriented either parallel or perpendicular to the fixture rails.1.1.2 Laminates of balanced and symmetric construction, with the 0° direction oriented either parallel or perpendicular to the fixture rails.1.1.3 Laminates composed of woven, braided, or knitted fabric filamentary laminae.1.1.4 Short-fiber-reinforced composites with a majority of the fibers being randomly distributed.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 are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.2.1 Within the text, the inch-pound units are shown in brackets.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

This specification covers composite ribbed steel pipe, precoated and polyethyene lined intended for use for gravity flow sanitary sewers, storm sewers, and other special applications such as water transmission pipe, rehabilitation pipe, slip line pipe, and irrigation pipe. Pipes shall be fabricated in full circular cross-section with helical lock seams and helical ribs projecting outwardly. Specimens cut from production pipe normal to and across the lock seam shall conform to the required values of tensile strength. The pipe shall conform to the required values of nominal inside diameter and sheet thickness. Joint connectors for composite ribbed steel pipe precoated and polyethylene lined shall be specified as soil tight, water-resistant, or watertight.1.1 This specification covers composite ribbed steel pipe, precoated and polyethylene lined intended for use for gravity flow sanitary sewers, storm sewers, and other special applications such as water transmission pipe, rehabilitation pipe, slip line pipe, and irrigation pipe where extra corrosion and abrasion resistance are required. The steel sheet used in the fabrication of the pipe has a polymer coating over a metallic coating of zinc on both sides. In addition, as the pipe is being fabricated, the ribs are filled with polyethylene and then a polyethylene liner is extruded onto the interior surface.1.2 The exterior polymer precoating provides extra protection of the steel against soilside corrosion, in addition to that provided by the metallic coating, and also provides a dielectric barrier for cathodic protection. The interior polymer precoating provides an adhesive layer between the galvanized steel and the polyethylene lining. The applied lining provides internal protection against corrosion, erosion, and abrasion. By filling the rib which has a deltoid shape (smaller at the opening in the pipe wall than at the bottom of the rib), the polyethylene is mechanically connected to the pipe wall and the polyethylene liner is then thermally bonded to the filled rib.1.3 This specification does not include requirements for bedding, backfill, or the relationship between earth cover load and sheet thickness of the pipe. Experience has shown that the successful performance of this product depends upon the proper selection of sheet thickness, type of bedding and backfill, controlled manufacture in the plant, and care in the installation. The installation procedure is described in Practice A798/A798M.1.4 This specification is applicable to orders in either inch-pound units as A978, or in SI units as A978M. Inch-pound units and SI units are not necessarily equivalent. SI units are shown in brackets in the text for clarity, but they are the applicable values when the material is ordered to A978M.1.5 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： 0元 / 折扣价： 0 元

4.1 This guide identifies proper layout, installation, and hydration procedures along with equipment for use by GCCM designers, inspectors, and installers.4.2 Applications—Typical GCCM applications may include but are not limited to:4.2.1 Hydraulic structure armoring or protection, including but not limited to: ditches, swales, canals, flumes, and other similar structures.4.2.2 Slope protection.4.2.3 Berm and bund lining and protection.4.2.4 Culvert invert lining.4.2.5 Scour protection at culvert inlets and outlets.4.2.6 Remediation of existing concrete channels and structures.4.2.7 Lining of outfalls and spillways.4.2.8 Mow strips or weed suppression.4.2.9 Lagoons and secondary containment berms (using GCCBs).1.1 This guide covers directions for the installation of geosynthetic cementitious composite mat (GCCM) materials under field conditions typically present in erosion control, hydraulic structure armoring and protection, and protection applications. This guide also covers directions for the installation of a special category of GCCMs known as geosynthetic cementitious composite barrier (GCCB) materials, under field conditions typically present in geotechnical or civil engineering applications, with the purpose of reducing or preventing the flow of fluid through the construction.1.2 The values in SI units are to be regarded as the standard. Values in inch-pound units are in parentheses for information.1.3 This guide contains general guidelines. It is not intended to replace project-specific installation requirements. In the event of a conflict between the two, the requirements of the project specifications will supersede the requirements of this guide.1.4 This is not an all-inclusive guide, and some projects will be beyond the scope of this guide.1.5 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.1.6 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

1. Scope and Objectives 1.1 Scope This Standard applies to suspension and dead-end composite insulators used on ac overhead transmission lines with a nominal voltage 69 kV or greater and a frequency not greater than 100 Hz. 1.2 Objectives The

定价： 592元 / 折扣价： 504 元

2. Scope and Field of Application 2.1 Type of Equipment This Standard applies to welded composite enclosures of cast and wrought aluminium and aluminium alloy enclosures pressurized with dry air, inert gases, eg, sulphur hexafluoride, carbon tetraflu

定价： 910元 / 折扣价： 774 元

5.1 The transport of any suspended solids or corrosion products from the preboiler cycle has been shown to be detrimental to all types of steam generating equipment. Corrosion product transport as low as 10 ppb can have significant impact on steam generators performance.5.2 Deposited corrosion products on pressurized water reactor (PWR) steam generator tubes can reduce heat transfer, and, if the deposit is sufficiently thick, can provide a local area for impurities in the bulk water to concentrate, resulting in a corrosive environment. In boiling water reactor (BWR) plants, the transport of corrosion products can cause fuel failure, out of core radiation problems from activation reactions, and other material related problems.5.3 In fossil plants, the transport of corrosion products can reduce heat transfer in the boilers leading to tube failures from overheating. The removal of these corrosion products by chemical cleaning is expensive and potentially harmful to the boiler tubes.5.4 Normally, grab samples are not sensitive enough to detect changes in the level of corrosion product transport. Also, system transients may be missed by only taking grab samples. An integrated sample over time will increase the sensitivity for detecting the corrosion products and provide a better understanding of the total corrosion product transport to steam generators.1.1 This practice is applicable for sampling condensed steam or water, such as boiler feedwater, for the collection of suspended solids and (optional) ionic solids using a 0.45-μm membrane filter (suspended solids) and ion exchange media (ionic solids). As the major suspended component found in most boiler feedwaters is some form of corrosion product from the preboiler system, the device used for this practice is commonly called a corrosion product sampler.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： 590元 / 折扣价： 502 元 加购物车