Nitrogen gas cylinder

The permeability of the set sealant is measured by an API-recommended permeameter, which consists of a cylindrical sealant holder that is filled with the setting slurry. Once the slurry has set, the holder is fitted on a base. The base has an opening for gas connection, which can be attached to a nitrogen gas cylinder. Gas at different pressures is applied, and the pressure difference is measured by a mercury column. Knowing the pressure difference, the cross sectional area of the holder, and its length, one calculates the permeability in millidarcies. Details of such a permeameter and the procedure may be found in the API Spec. [3]. 

DS2, 1 1/2 Quart (including ABC-M11). The Mil is used to decontaminate small areas that soldiers must touch. It is a steel container with an aluminum spray-head assembly and a nitrogen gas cylinder that provides the pressure. It is filled with 1-1/3 quarts of DS2, which is sufficient to cover 135 square feet. The ABC-M11 is an equipment-mounted, standard U.S. Army decontaminating apparatus used for operator spray-down decontamination. The item is man-portable (weight of approximately 5 pounds). The ABC-M11 has been replaced by the M13. 

Oxygen-free nitrogen in cylinders is available commercially but is, of course, more expensive than the normal commercial compressed gas. 

The synthesis gas cylinder should be installed with an instrument-quality forward pressure regulator, since this will control the experimental pressure of the whole unit. The nitrogen cylinder can have an ordinary regulator, because it is used only for flushing the unit. 

A cylinder contains nitrogen gas and a small amount of liquid water at a temperature of 25°C (the vapor pressure of water at 25°C is 23.8 mm). The total pressure is 600.0 mm Hg. A piston is pushed into the cylinder until the volume is halved. What is the final total pressure ... 

Nickel Alloys Alloy C-4 (16 Cr, 16 Mo, Balance Ni) and alloy C-276 (16 Cr, 16 Mo, 3.5 W, 5 Fe, balance Ni) have been used for closure seals on cryogenic gas cylinders because the alloys retain all their ductility down to -327°C (—557°F). The impact strength at liquid nitrogen temperatures is the same as that at room temperature. 

Apparent near the bench on which the GC unit sits are pressure-regulated compressed gas cylinders of hydrogen and air (in addition to the carrier gas, helium or nitrogen). Metal tubing, typically ]/8-in. diameter, connect the cylinders to the detector. A needle valve is used for flow control. These valves are located in the instrument for easy access and control by the operator. 

The titration is shown schematically in Figure 6-5. Nitric oxide, compressed with nitrogen in a gas cylinder, is then metered into the apparatus along with the clean-air stream but without the ozone. In this way, the initial nitric oxide concentration is measured with the nitric... 

Any residual material left in the shuttle is blanketed by a slow flow of dry nitrogen gas to prevent fouling of the shuttle between uses. Pneumatic cylinders, driven from solenoid valves that are controlled by a power- and event-controller, provide the shuttle motion, and position is confirmed by Hall Effect detectors on the pneumatic cyhnders and monitored by the power and event controller. 

Burkhardt, M. R N. I. Maniga, D. H. Stedman, and R. J. Paur, Gas Chromatographic Method for Measuring Nitrogen Dioxide and Peroxyacetyl Nitrate in Air without Compressed Gas Cylinders, Anal. Chem., 60, 816-819 (1988). 

When the reservoir (with a one-hole connector) was filled with water, salts were added and the compounds were spiked. The pH was adjusted with 1 N HC1 to 7.0. The reservoir was capped and swirled for a few seconds. The upper and lower stopcocks were opened and pressure was applied by using high-pressure, ultrapure, nitrogen gas. The flow rate was controlled by the nitrogen cylinder pressure and by using the fine adjustment on the resin column stopcock. Two flow rates were studied and are described during the presentation of results. The initial flow rate used was 120-150 bed volumes/h (20-25 mL/min). A lower flow rate of approximately 48 bed volumes/h was studied after breakthrough of quinaldic acid was observed. 

Oxygen-free nitrogen can be obtained from cylinders, but must be filtered to remove oil contaminants. Liquid nitrogen provides a better supply of gas, but impurities accumulate at the bottom of the Dewar flask, so that the bottom 10% should not be used (Johnson, 1990). Accessories to monitor and purify nitrogen gas are available commercially. 

Even if reactions of this sort are carried out only relatively infrequently, it is advisable to set up a simple nitrogen (or argon) line which will facilitate many of the operations described in this section. The line leading from the gas cylinder is shown diagrammatically in Fig. 2.70. 

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