Vapor testing procedure

Diverse appHcations for the fabric sometimes demand specialized tests such as for moisture vapor, Hquid transport barrier to fluids, coefficient of friction, seam strength, resistance to sunlight, oxidation and burning, and/or comparative aesthetic properties. Most properties can be deterrnined using standardized test procedures which have been pubHshed as nonwoven standards by INDA (9). A comparison of typical physical properties for selected spunbonded products is shown in Table 2. 

A variety of test procedures and use guidehnes have been developed. In addition, companies or associations may develop internal standards. The Federal Register, 33 CFR, Part 154, contains the USCG requirements for detonation arresters in marine vapor control... 

Hydrocarbon vapor migration within the carbon canister is a significant factoi during the real time diurnal test procedure. The phenomenon occurs after the canister has been partially charged with fuel vapors. Initially the hydrocarbons will reside primarily in the activated carbon that is closest to the fuel vapor source. Over time, the hydrocarbons will diffuse to areas in the carbon bed with lower HC concentration. Premature break through caused by vapor migration for twc different canisters is shown in Fig. 17. The canister with the L/D ratio of 5.0 shows substantially lower bleed emissions than the canister with an L/D ratio of 3.0. 

Given the absenee (or near absenee) of Mel in these reaetions, we sought to demonstrate the proeess on a eontinuous proeess. We purposely ehose to employ the same vapor take-off (vapor stripped) reaetor we used in om earher studies of the Rh/Mel co-catalyzed carbonylation of methanol (3) since the vapor stripping procedure used in the process would force any Mel formed in situ overhead where we could detect it in the effluent. This would represent the most rigorous test of the new non-Mel process we could contrive. 

The apparatus used to determine the explosive nature of vapors is shown in Figure 6-14. The test procedure includes (1) evacuating the vessel, (2) adjusting the temperature, (3) metering in the gases to obtain the proper mixture, (4) igniting the gas by a spark, and (5) measuring the pressure as a function of time. 

The standard astm test method (D-1149-64) for rubber damage includes a test chamber (volume, 0.11-0.14 m ) through which ozonized air flows at a rate greater than 0.6 m/s. Because the residence time of the ozonized air in the test chamber is about 1 s, the ozone may be expected to reach the material in about 0.1 s. A somewhat similar test procedure (aatcc test method 109-1972 ansi L14, 174-1973) is used in testing colorfastness. The ozone generator is usually (but not necessarily) a mercury-vapor resonance lamp with emission lines at 184.9 and 253.7 nm. The 184.9-nm line is absorbed, and two ground-state oxygen atoms are produced ... 

Detonation Arrester Testing Requirements are described by various agencies in the aforementioned documents (UL 525, etc.). For installations governed by the USCG in Appendix A of 33 CFR, Part 154 (Marine Vapor Control Systems), the USCG test procedures must be followed. These are similar but not identical to those of other agencies listed (for a discussion of differences, see Deflagration and Detonation Flame Arresters, 1993). 

Test Methods. Tests for water repeUency of concrete and masonry have been described by several authors (72,94). The National Bureau of Standards (NBS) evaluated fifty-five clear water repeUents for masonry surfaces (95). Performance tests included water absorption, water-vapor transmission, resistance to efflorescence, change in appearance, and durability to accelerated and outdoor weathering. More recently, the National Cooperative Highway Research Program conducted a study of several organic and sihcone water-repeUent treatments. The results are communicated in Report 244 (96). The testing procedure used in this study is now a popular method for evaluating water-repeUent treatments on concrete. 

C. Test Procedure. The test procedure for vapor pressure determination was as follows ... 

Flammable hquids are divided into various classes, as given in Table 3.4. The definitions depend upon the flashpoints and in some cases the boiling points of the liquids. The flashpoint of a liquid is l aUy defined in terms of specific test procedures used to determine it, but conceptually it is the minimum temperature at which a hquid forms a vapor above its surface in sufficient concentration that it may be ignited. In Table 3.4, the first temperature is in degrees Celsius and the temperature in parentheses () is the equivalent Fahrenheit temperature. 

Flash point (5 ) - This is the minimum temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture with air near the surface of a liquid. The experimental values for this quantity are defined in terms of specific test procedures which are... 

Depending on the viscosity of liquid and its expected flash point range, one of the above methods is chosen as described in detail elsewhere. It should be additionally noted that if the flash point method uses continuous heating, it is not suitable for testing mixtures of flammable substances because their vapor concentrations are not representative of equilibrium eonditions. One of the weaknesses of flash point analysis is that the flame is well above the liquid surface therefore full vapor concentration is not attained. Many cases exist where a flash point cannot be detected but the material does form flammable mixtures. Before a method is chosen and a data interpretation made full information on the test procedure should be studied in detail and the proper authorities should be eonsulted to define safe practices for a particular material. 

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