Piping double-wall

Table 5 Comparison of wire IQI sensitivities obtained with Selenium and iridium for different pipe diameters and thicknesses (DW=double wall, SW=single wall)[2].

In fig, 4 local corrosion by erosion is shown in a pipe with a bore of 100 mm behind a welding. In this case only the nominal wall thickness of the pipe is known (6.3 mm). To calibrate the obtained density changes into wall thickness changes a step wedge exposure with a nominal wall thickness of 13 mm (double wall penetration in the pipe exposure) and the same source / film system combination was used. From this a pcff = 1-30 1/cm can be expected which is used for the wall thickness estimation of the pipe image according to equation (4). 

Fig. 4 Corrosion inside a pipe (bore 100 mm, wall thickness 6.3 mm), projection technique at 160 kV (double wall penetration), profile plot with calibrated wall thickness loss...

At very low temperatures with hquid air and similar substances, the tank may have double walls with the interspace evacuated. The weh-known Dewar flask is an example. Large tanks and even pipe hues are now built this way. An alternative is to use double walls without vacuum but with an insulating material in the interspace. Perlite and plastic foams are two insulating materials employed in this way. Sometimes both insulation and vacuum are used. 

Use double walled pipe with annular nitrogen purge and monitoring capabilities... 

Using double-walled pipes, tanks, and other containers... 

Porous Vycor glass tube (in double pipe configuration), wall thickness 3 mm, length 600 mm, outer diameter 15 mm, mean pore diameter 45 A. Feed enters the reactor at shell side, permeate at tube side. ... 

Porous alumina tube (in double pipe configuration), wall thickness 1 mm, length 200 mm, outer diameter,... 

At very low temperatures with liquid air and similar substances, the tank may have double walls with the interspace evacuated. The well-known Dewar flask is an example. Large tanks and even pipe... 

For chemicals that pose severe release hazards, one effective but costly way to provide spill containment is to use a double wall on the vessel or piping (CCPS, 1988b). Often construction materials for the outer (secondary) wall are the same as those of the primary inner wall. In case of inner-wall failure,... 

Figure 5.1 is a simplified schematic drawing of a double-wall pipe. The hazardous material flows in the inner pipe. The annular space is purged with a flow of nitrogen gas. The discharge of the nitrogen from the annular space is analyzed to detect a leak of the inner pipe. Note that the inlet and outlet valves for nitrogen to the annular space are car-sealed-open (CSO) or locked open (LO). 

An experimental setup similar to the Zimmerman photolysis cell was utilized by Lazare et al. (60) to determine the quantum yield for the photoreaction of a substrate adsorbed on silica gel. The photolysis cell consists of an aluminum dish for the powdered silica gel sample, which is covered by a double-walled hemispherical Pyrex cap filled with ferrioxalate actinometers solution. The sample is irradiated through a quartz light pipe, which enters the photolysis cell through a hole at the top of the cap. Thus, nearly all scattered light from the silica gel sample is absorbed by the surrounding actinometer solution, and the amount of light absorbed by the substrate (which is adsorbed on the silica gel surface) is determined by a similar subtraction method as described in the Zimmerman experiment (vide supra). 

Fig. 7.4. The proton beam strikes the lead target generating neutrons which are moderated in the surrounding heavy water blanket. Molten salt carrying fissile material for heat generation and electric power production circulates in the heavy water blanket through double-walled pipes. Some of this power drives the accelerator. Nuclear waste including that produced in the molten salt is also circulated through the blanket in a separate loop and transmuted to stable and short-lived nuclides which are extracted and...

The double walled vacuum jacketed storage tanks and piping that are required for liquid hydrogen are expensive compared to conventional fuel storage tanks. A gasoline tank might cost about 150, while a liquid... 

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