定价： 0元 / 折扣价： 0 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Test Method F2656/F2656M states that variable-width barriers shall be tested in minimum- and maximum-width configurations. Interpolations between maximum and minimums are allowed if there are no structural modifications made to the barrier (that is, all structural components, including spacing of support members and connections, are similar between the two barriers tested at minimum and maximum widths). Extrapolation outside of the tested minimum- and maximum-width configurations is not allowed.5.2 However, there is a class of barriers such as some nets and fences that rely on a structurally repetitive interior system and strengthened end terminals or anchorages that are not explicitly treated under Test Method F2656/F2656M. There are situations where the interior system of the barrier could be exceptionally long and it is impractical or impossible to test the maximum-width configuration due to test facility site constraints, as an example.5.3 When a variable-width barrier is dependent on a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals, this practice shall be used to establish the maximum-width configuration that is equivalent to an infinitely long barrier.5.4 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Knowing the condition designation and penetration rating provides the ability to select an appropriate barrier for site-specific conditions around a facility.5.5 Use of this practice assumes:5.5.1 Except for the instrumented end terminations, the structurally repetitive interior system is constructed and installed in a manner that represents the proposed actual service installation;5.5.2 Except for the instrumented end terminations, the structurally repetitive interior system conforms to supplier specifications and drawings;5.5.3 The actual service installation of the structurally repetitive interior system shall be terminated using the strengthened end terminals used for the minimum-width configuration test; and5.5.4 The instrumented end terminations used for the maximum-width configuration shall provide axial load resistance only.1.1 This practice provides a procedure for applying Test Method F2656/F2656M test criteria to an exceptionally long (that is, 300 ft [91 m] or greater) variable-width vehicle barrier as defined by Test Method F2656/F2656M.1.2 This practice provides a procedure to establish a maximum-width configuration that is equivalent to an infinitely long barrier for a variable-width barrier as defined by Test Method F2656/F2656M.1.3 This practice applies only to variable-width barriers that are dependent on both a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals.1.4 This practice applies only when it is impractical or impossible to install the maximum-width test article of a variable-width barrier because the test facility site constraints limit the practical length of the test article.1.5 This practice does not apply when its use is employed solely with the intent of reducing the test article installation cost when it is practical to test the maximum-width installation length.1.6 This practice does not apply to continuous or other types of vehicle barriers.1.7 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Further, the complete variable-width barrier shall receive a single penetration rating that is determined as the maximum penetration rating for both the minimum- and maximum-width configurations tested, and is taken to be the final penetration rating. The penetration rating is not based on engineering calculation or judgment.1.8 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.1.9 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.1.10 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： 345元 / 折扣价： 294 元 加购物车

定价： 156元 / 折扣价： 133 元

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

5.1 Asphaltenes are naturally occurring materials in crude petroleum and petroleum products containing residual material. The asphaltenes are usually present in colloidal suspensions, but they may agglomerate and flocculate if the suspension of asphaltene molecules is disturbed through excess stress or incompatibility. This test method provides compatibility parameters, which can be used to assess stability reserve and compatibility.5.2 A blend is considered stable when the blend’s peptizing power is higher than the blend’s maximum flocculation ratio;3,4 both of them can be calculated using empirical blend rules. Refineries and terminal owners can prevent the flocculation of asphaltenes due to incompatibility by assessing the compatibility of fuels beforehand.NOTE 4: See Appendix X1 for an example of prediction of compatibility.1.1 This test method covers a procedure for quantifying the maximum flocculation ratio of the asphaltenes in the oil and the peptizing power of the oil medium, by an automatic instrument using an optical device.1.2 This test method is applicable to atmospheric or vacuum distillation residues, thermally cracked residue, intermediate and finished residual fuel oils, containing at least 1 % by mass asphaltenes. This test method has not been developed for asphalts.NOTE 1: An optical probe detects the formation of flocculated asphaltenes. The start of flocculation is interpreted when a significant and sustained increase in rate-of-change of signal, as measured by the optical probe, ensures flocculation is in progress. The start of flocculation can be detected unambiguously when the sample contains at least 1 % mass asphaltenes as measured by Test Method D6560.NOTE 2: This test method is applicable to products typical of Specification D396—Grades 5L, 5H, and 6, and Specification D2880—Grades 3-GT and 4-GT.1.3 This test method was evaluated in an interlaboratory study in the nominal range of 32 to 76 for the maximum flocculation ratio and in the nominal range of 36 to 95 for peptizing power.NOTE 3: The nominal range is determined by (min. sample mean—Reproducibility) to (max. sample mean + Reproducibility).1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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： 646元 / 折扣价： 550 元 加购物车

1.1 This specification covers cold-rolled carbon commercial sheet (CS), in coils or cut lengths. This material is intended for exposed or unexposed parts where bending, moderate drawing, forming, and welding may be involved.1.2 This specification is not applicable to Specification A109. Narrow widths multiple slit from wide sheet are not strip, unless they qualify as strip because of thickness, special finish, special edge, or special temper.1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI 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 specification.

定价： 0元 / 折扣价： 0 元

定价： 515元 / 折扣价： 438 元 加购物车

定价： 646元 / 折扣价： 550 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

定价： 515元 / 折扣价： 438 元 加购物车

This practice establishes the basic design and proper installation procedures for flexible thermoplastic piping systems for underground irrigation systems that operate at maximum working pressures of 125 psi. The thermoplastic pipes shall be made of poly(vinyl chloride) (PVC) or polyethylene (PE), and shall be assembled to withstand the design working pressure for the pipeline without leakage, internal restriction, or obstruction that could reduce line capacity below design requirements. The piping system shall conform to requirements for the working pressure, service factor, system capacity, friction losses, flow velocity, outlets, check valves, pressure-relief valves, and air-release and vacuum-relief valves. The procedures for trench and joints preparation, thrust block construction, line charging, and backfilling are also detailed thoroughly.1.1 This practice establishes procedures for the design and installation of thermoplastic flexible piping systems, for underground irrigation systems. Because there is considerable variability in end-use requirements, soil conditions, and thermoplastic piping characteristics, the intent of this practice is to outline general objectives and basics of systems design, proper installation procedures, and to provide pertinent references.1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units which are for information only and are not considered 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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元