5.1 Knowledge of gas solubility is of extreme importance in the lubrication of gas compressors. It is believed to be a substantial factor in boundary lubrication, where the sudden release of dissolved gas may cause cavitation erosion, or even collapse of the fluid film. In hydraulic and seal oils, gas dissolved at high pressure can cause excessive foaming on release of the pressure. In aviation oils and fuels, the difference in pressure between take-off and cruise altitude can cause foaming out of the storage vessels and interrupt flow to the pumps.1.1 This test method covers the estimation of the equilibrium solubility of several common gases encountered in the aerospace industry in hydrocarbon liquids. These include petroleum fractions with densities in the range from 0.63 to 0.90 at 288 K (59°F). The solubilities can be estimated over the temperature range 228 K (−50°F) to 423 K (302°F).1.2 This test method is based on the Clausius-Clapeyron equation, Henry's law, and the perfect gas law, with empirically assigned constants for the variation with density and for each gas.1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.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.

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It is important to have the sulfur content of liquefied petroleum gases at low enough concentration to meet government regulations. The presence of sulfur can result in corrosion of metal surfaces. Sulfur can be poisonous to catalysts in subsequent processing.1.1 This test method covers the determination of total sulfur in liquefied petroleum gases containing more than 1 μg/g. Specimens should not contain more than 100 μg/g of halogens.1.2 To attain the quantitative detectability that the test method is capable of, stringent techniques must be employed and all possible sources of sulfur contamination must be eliminated. In particular, cleaning agents, such as common household detergents which contain sulfates, should be avoided.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.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 and health practices and determine the applicability of regulatory limitations prior to use.

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1.1 Scope 1.1.1 This standard applies to newly produced unvented catalytic room heaters (see Part IV, Definitions), hereinafter referred to as heaters, constructed entirely of new, unused parts and materials, having input ratings up to and including

定价： 4232元 / 折扣价： 3598 元

1.1 Scope 1.1.1 This standard applies to newly produced unvented catalytic room heaters (see Part IV, Definitions), hereinafter referre d to as heaters, constructed entirely of new, unused parts and materials, having input ratings up to and including

定价： 819元 / 折扣价： 697 元

1 Scope This part of ISO 9170 specifies requirements for terminal units intended for use in medical gas pipeline systems in accordance with ISO 7396-1, for use with the following services: - oxygen; - nitrous oxide; - air for breathing; - carbon d

定价： 728元 / 折扣价： 619 元

Preface The standards set forth herein apply to the third edition of the Standard for Gas-Fired Unvented Catalytic Room Heaters for Use with Liquefied Petroleum (LP) Gases, ANSI Z21.76-1994, and Addenda Z21.76a-1996, and supersede corresponding standar

定价： 865元 / 折扣价： 736 元

定价： 819元 / 折扣价： 697 元

定价： 546元 / 折扣价： 465 元

5.1 This test method provides an accurate and reliable procedure to measure the total heating value of a fuel gas, on a continuous basis, which is used for regulatory compliance, custody transfer, and process control.5.2 Some instruments which conform to the requirements set forth in this test method can have response times on the order of 1 min or less and can be used for on-line measurement and control.5.3 The method is sensitive to the presence of oxygen and nonparaffin fuels. For components not listed and composition ranges that fall outside those in Table 1 and Table 2, modifications in the method and changes to the calibration gas or gasses being used may be required to obtain correct results.1.1 This test method covers the determination of the heating value of natural gases and similar gaseous mixtures within the range of composition shown in Table 1, and Table 2 that covers flare components but is not intended to limit the components to be measured in flare gases.1.2 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.1.3 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.

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5.1 The LFL and UFL of gases and vapors define the range of flammable concentrations in air.5.2 This method measures the LFL and UFL for upward (and partially outward) flame propagation. The limits for downward flame propagation are narrower.5.3 Limits of flammability may be used to determine guidelines for the safe handling of volatile chemicals. They are used particularly in assessing ventilation requirements for the handling of gases and vapors. NFPA 69 provides guidance for the practical use of flammability limit data, including the appropriate safety margins to use.5.4 As discussed in Brandes and Ural,4 there is a fundamental difference between the ASTM and European methods for flammability determination. The ASTM methods aim to produce the best representation of flammability parameters, and rely upon the safety margins imposed by the application standards, such as NFPA 69. On the other hand, European test methods aim to result in a conservative representation of flammability parameters. For example, in this standard, LFL is the calculated average of the lowest go and highest no-go concentrations while the European test methods report the LFL as the minimum of the five highest no-go concentrations.NOTE 2: For hydrocarbons, the break point between nonflammability and flammability occurs over a narrow concentration range at the lower flammability limit, but the break point is less distinct at the upper limit. For materials found to be non-reproducible per 13.1.1 that are likely to have large quenching distances and may be difficult to ignite, such as ammonia and certain halogenated hydrocarbon, the lower and upper limits of these materials may both be less distinct. That is, a wider range exists between flammable and nonflammable concentrations (see Annex A1).1.1 This test method covers the determination of the lower and upper concentration limits of flammability of chemicals having sufficient vapor pressure to form flammable mixtures in air at atmospheric pressure at the test temperature. This test method may be used to determine these limits in the presence of inert dilution gases. No oxidant stronger than air should be used.NOTE 1: The lower flammability limit (LFL) and upper flammability limit (UFL) are sometimes referred to as the lower explosive limit (LEL) and the upper explosive limit (UEL), respectively. However, since the terms LEL and UEL are also used to denote concentrations other than the limits defined in this test method, one must examine the definitions closely when LEL and UEL values are reported or used.1.2 This test method is based on electrical ignition and visual observations of flame propagation. Users may experience problems if the flames are difficult to observe (for example, irregular propagation or insufficient luminescence in the visible spectrum), if the test material requires large ignition energy, or if the material has large quenching distances.1.3 Annex A1 provides a modified test method for materials (such as certain amines, halogenated materials, and the like) with large quenching distances which may be difficult to ignite.1.4 In other situations where strong ignition sources (such as direct flame ignition) is considered credible, the use of a test method employing higher energy ignition source in a sufficiently large pressure chamber (analogous, for example, to the methods in Test Method E2079 for measuring limiting oxygen concentration) may be more appropriate. In this case, expert advice may be necessary.1.5 The flammability limits depend on the test temperature and pressure. This test method is limited to an initial pressure of the local ambient or less, with a practical lower pressure limit of approximately 13 kPa (100 mm Hg). The maximum practical operating temperature of this equipment is approximately 150 °C.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test method may be used as elements of a fire risk assessment that takes into account all of the factors pertinent to an assessment of the fire hazard of a particular end use.1.8 This standard may involve hazardous materials, operations, and equipment. 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. Specific precautionary statements are given in Section 8.1.9 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： 646元 / 折扣价： 550 元 加购物车

5.1 Certain gases have excellent dielectric and electric arc interruption characteristics which make their use in electrical installations very desirable.5.2 Water content, as the test parameter, is of great importance in determining the dielectric effectiveness of the gas. Under certain conditions, water may condense and become a conducting liquid resulting in a catastrophic dielectric breakdown of the insulation. The water content of these insulating gases as expressed by dew point is listed in Specifications D1933, D2472, and D3283.5.3 Once the dew point is determined, a conversion to moisture content may be performed using Table 1. Once moisture content is known, the lowest temperature at which gas insulated equipment can be safely operated can usually be determined by reviewing manufacturers' specifications for the equipment.(A) Vapor pressures in atmospheres at various dew points can be obtained by dividing the values for “volume percent'' in this table by 100. Calculations for this table were made by using the International Critical Table values for the vapor pressure of ice and liquid water. The vapor pressure of liquid water was used for values from 50 to 0°C. The vapor pressure of ice was used from 0 to − 81°C.5.4 The dew point of the test gas is independent of the gas temperature but does depend on its pressure. Many moisture measurement test instruments are sensitive to pressure, and display moisture values at the instrument inlet pressure and not necessarily at the pressure of the system being sampled. It is therefore important to account for this condition to avoid serious measurement errors.1.1 These test methods describe the determination of the water vapor content of electrical insulating gases by direct or indirect measurement of the dew point and the calculation of the water vapor content.1.2 The following four test methods are provided:1.2.1 Method A describes the automatic chilled mirror method for measurement of dew point as low as − 73°C (−99°F).1.2.2 Method B describes the manual chilled mirror or dew cup method for measurement of dew point as low as − 73°C (−99°F).1.2.3 Method C describes the adiabatic expansion method for measurement of dew point as low as − 62°C (−80°F).1.2.4 Method D describes the capacitance method for measurement of dew point as low as − 110°C (−166°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. For specific warnings, see 8.1.1, 9.2, 10.1.2 and 10.2.5.

定价： 590元 / 折扣价： 502 元 加购物车