Thickness, steel

Small differences of the correlator output can be explained taking into account inevitable variations of the sheet steel thickness. 

Gammagraphic weld inspection in the lower range of steel thicknesses has been done with Iridium and Ytterbium isotope sources throughout the past. The large majority of applications has been using Iridium due to the unfavourable economical parameters of Ytterbium, obviously with non-optimal results at thin wall inspections. 

The paper presents the results from systematic comparisons of contrast and resolution obtained with different types of radiation sources on steel thicknesses from 5 to 40 mm. These results have been taken into account with the definitions of the European standard for radiographic inspection of weldments (EN 1435) that is approved since 1997. Conclusions from practical investigations on pipe line sites, in petrochcemical plants and in nuclear power stations will be discussed as well. Furthermore, the presentation will stipulate a variety of advantages obtained from the new source in terras of coUimation and radiation protection. 

Under practical conditions this can be measured/visualized by the difference in the detection of wire IQI s. The published results (e.g. [2,3,4]) show a difiference of approximately 1 - 2 wires below 10 mm of steel thickness and 1 wire above in favour of Selenium. 

Due to the possibility of selecting the radiation energy of X-ray tubes in accordance with the material thickness under investigation there is another increase in wire sensitivity at low steel thicknesses. Starting from approx. 20 - 25 mm steel thickness the differences between X-rays and Selenium decrease and merge at about 40 mm. 

Table 6 Comparison of CERL double wire sensitivity vs. steel thickness for Selenium, Iridium and X-rays [4]...

Practical applications [2] of a GammaMat M model using the new Selenium crawler camera loaded with approx. 1 TBq (30Ci) on a pipeline of diameter 12 and wall thickness of 0.25 showed 6-7 m axial distance to the exposed source as limit of the radiation controlled area (40pSv/h) and 22m perpendicular to the pipeline. Other authors [3] have reported about a comparison for Ir-192 and Selenium source on a 4.5 diameter pipe and 0,125 steel thickness they have found for 0.7 Tbq (18Ci) Selenium a value of 1 Om behind the film (in the unshielded beam) comparing under same conditions to approx. 40m for Iridium. 

Comparative costs for conveyor systems can be based only on studies of specific problems. For example, belt-conveyor idlers are available in a range of quahties that may make the best unit cost three times as much as the cheapest. Bearing quahty, steel thickness, and diameter of rolls all affect cost, as does design for easy maintenance and repair. Therefore, it is necessary to make cost comparisons on the basis of a specific study for each conveyor application. 

Steel thickness. Loss rate (mm/year) (average minimum and maximum rates)... 

In addition, we determined the work function directly by taking UPS measurements under UHV conditions for the three different pure materials on a Fe substrate. We obtain the following values graphite, pure, 3.8 eV carbon black, pure, 4.1 eV P3FIT, pure, on stainless steel (thickness <500 pm),... 

Figure 7.61 Regions of stress intensity factor and H2S concentration which may or may not lead to crack formation in a casing steel with yield strength Oy = 900 MPa. Steel thickness 9 mm. Environment 5% NaCl solution at 25-80 C (further explanation is given in the text). (After Edwards [7.55].)...

Fig. 3.12. Typical heating rates for various steel thicknesses in a batch reheat furnace. The dashed lower end of the curve indicates that greater than 6 (0.15 m) steel thickness is not recommended for one-side heating. (See also fig. 4.21.)...

Fig. 4.21. Heating rates for various steel thicknesses. (See also fig. 3.12.)...

All. samples 27S g/m coating weight (ambient cooled) steel thickness, 0.65 mm. 

The good experience with galvanized steel in soils of controlled composition has led to the wide use of galvanized steel in this new industry. A French standard NF A 05-252 (1990) specifies backfill and steel thickness for different service lives, both with galvanized steel and with ungalvanized (Table 4.5) pH must be between 5 and 10 (Jailloux, 1990). 

Table 4.5 Earth Reinforcement Minimum Steel Thickness (mm) to be Reserved for Corrosion Losses... 

Core No. Bundle Thickness Z(ih.) Shim Steel Thickness X(in.) Boron Steel Total Stainless Boron Thickness Steel Weight Weight Y (in.) (g) (g) M/W Volume Ratio ... 

K was found that the presence of 1.27-cm-thick steel outside either craitainer resulted in the maximum decrease in reactivity from that with water alone this reactivity change was approximately 2.8 and 1.8 for the 33.02- and 39.09-cm-diam cylinders, respectively. Further increase in steel thickness up to 5.08 cm increased the - reactivity, but not to that existing with water alone. Interposition of 0.081-cm-thick cadmium between the 39.09-cm-diam solution cylinder and the steel decreased the reactivity of the cylindrical volume from that without the cadmium however, the presence of cadmium between the 5.08-cm-thick steel reflector and the water resulted in no reactivity change. These latter measurements emphasize the Importance of the relative lobations of neutron-absorbing materials in the evaluation of the nukdear criticality safety of water-reflected containers. 

Oil Reflected Average Fuel Density (g/cm ) Steel Thickness. (cm) Observed Critical Massh (grams) Computed Critical Mass (grams) Scaled Critical Mass (grams)... 

The critical masses reported here are of interest since, owing to handling difficulties, only a limited number of plutonium-metal critical mass measurements have been reported. Specific conclusions include the critical masses of steel-oil reflected assemblies are increased, relative to oil-only reflection the curve of critical mass variation with steel thickness, for steel-< reflection of hemispherical asseinblies, shows structure, which is similar to that found in previous enriched-uran-lum metal measurements on spherical assemblies. The structure observed consists of a pair of inflectlan points at steel thicknesses of 2 and cm together with a maximum at 3 cm. This structure has been shown to a be associated with the scattering resonances of Fein the energy range 20 to 100 keV. 

A constant pressure bomb is a steel, thick-walled tube cylinder. It is pupped with... 

If the steel thickness is increased to 1.5 mm, the imbalance in tube flexibility results in the stress level being increased at one end, beyond the elastic limit. This effect is clearly seen in Fig. 35. 

The principal equipment used is the open top pan or kettle holding between 100 and 300 tonnes of molten lead. Figure 12.2 shows a cross-section of a typical refining kettle of 3.4 m diameter, but diameters vary from 2.5 to 4 m. The upper cylindrical part of a 3.4 m diameter 200 tonne kettle is around 1.5 m long, and 10 mm of depth represents one tonne of lead. Steel thickness is 30 mm and unalloyed steel is used (ASTM -A284-55T). The kettle sits within a brick furnace fired by natural gas or oil and with provision for air cooling. The level of the operating floor of the refinery is usually one metre below the rim of the kettle so that the fiimace is located and accessed from a lower floor or basement. 

Estimate the maximum heat of reaction that can be removed through the wall of a stirred reactor, operating at a temperature of 120 C. The reaction medium is a dilute aqueous solution. The reactor is cooled with water. A first estimate of the mean temperature of the cooling water is 30 C. The reactor has a diameter of 2 m, liquid height also 2 m. Jacket surface 15 m. Diameter turbine 0.6 m, stirrer speed Is. The jacket has a hydraulic diameter of 0.05 m, the flow rate of the cooling water is 1 m/s. The reactor wall is made of steel, thickness is 2 mm. The heat conductivity of steel is 80 W/m K. 

In roll bonding, layers of two metals are mated by heavy rolling in a mill after the surfaces have been thoroughly cleaned and treated. Clad thicknesses of 5 to 10 percent of the base steel thickness are common. Some small areas of unbonded metal will be present. Two metals may also be coextruded through a die. 

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