Frost line

Changing the ambient temperature around the pipe to a temperature that 1 avoid low-temperature problems. Burying water pipes below the frost line or running them through a heated building are the two most common examples of this method. 

For high, heavy tanks, a foundation ring may be needed. Prestressed concrete tanks are sufficiently heavy to require foundation rings. Foundations must extend below the frost line. Some tanks that are not flat-bottomed may also be supported by soil if it is suitably... 

In the tubular process a thin tube is extruded (usually in a vertically upward direction) and by blowing air through the die head the tube is inflated into a thin bubble. This is cooled, flattened out and wound up. The ratio of bubble diameter to die diameter is known as the blow-up ratio, the ratio of the haul-off rate to the natural extrusion rate is referred to as the draw-down ratio and the distance between the die and the frost line (when the extrudate becomes solidified and which can often be seen by the appearance of haziness), the freeze-line distance. 

Good foundations assure stability of the equipment. Tlie foundaUon should extend below the soil frost line to eliminate setUing of equipment. Major loads and equipment producing vibrations (e.g., pmiips) should not be placed on filled ground. High towers and major vessels should have properly installed anchor bolts. 

Stemwalls, also called frost walls, are below-grade foundations that support the load of the abovegrade walls and thereby the roof. There is usually a footing beneath them at some depth below the frost line. The major radon-related issue for these walls is the geometry of the slab/stemwall joint. This will be covered in the section on floors. If stemwalls are constructed of concrete blocks, then the block tops should be sealed. 

The primary reason to place a post at deeper depths in the northern midwest is frost heave. The post hole needs to be below the frost line. What is this depth in each city ... 

In addition, the thermal diffusivity of the soil at both locations varies from a = 10 to 0 = 10 m /s. The post hole depth must be below the frost line, so that we do not have frost heave on our posts. The frost line would be at the depth where temperature never goes below freezing, T = 0°C. We should set the cosine term from equation (E4.2.2) to -1 and set the temperature to 0°C to determine this depth ... 

The vap. press, curve of solid iodine is indicated by PO, Fig. 16 that of liquid iodine by 00 and the effect of press, on the m.p. of iodine by ON. At the triple point 0 these curves meet. Fig. 18 shows a similar curve for water. The curve PO thus represents the sublimation curve or hoar-frost line OC. the boiling or vaporization curve, i.e. the effect of press, on the b.p. of the liquid. The same phenomenon occurs with water, iodine, etc., and the principle involved is the same as indicated in the law represented by Clapeyron-Clausius equations with respect to the lowering of the m.p. by an increase of press. Consequently, if the vap. press, of iodine be less than that of th,e triple point, the solid does not melt, but rather sublimes directly without melting at the triple point at 114-15° (89 8 mm.) and A. von Richter at 116 1° (90 mm.). According to R. W. Wood, if the condensation of iodine vapour occurs above —60°, a black granular deposit is formed, but below that temp, a deep red film is produced. 

With crystalline types [not amorphous (Chapter 1)], melt leaving the die (and moving to a ring-shaped zone where the film approaches its diameter) changes from a hazy to a transparent (amorphous) condition. The level at which this transition occurs is the frost line. This zone is characterized by a frosty appearance to the film caused by the film temperature falling below the softening range of the plastic. 

The Research Unit lies within the rain shadow of the Cascade Mountains of Washington. The average yearly rainfall of the area is 9.00 inches, only about 8% of which falls from mid-June to mid-September. During the same 3 months the rate of evaporation is three times as great as the average annual rainfall. Because of this and the low intensity of the rainfall, surface runoff occurs only from the shallow layer above the frost line. 

Fig. 3 Schematic of spiral mandrel blown film die operation (1) ring-shaped melt distribution (2) die body (3) spiral flow mandrel (4) sizing ring (5) spreader (6) film bubble (7) frost line (8) solidified film (9) bubble collapsing rollers (10) nip rollers (11) external bubble cooling air (12) internal bubble cooling air inlet (13) internal bubble cooling pipe and (14) heated internal bubble air return.

The specific volumes and the latent heats are generally quite different from the three changes of state, and therefore the slopes of the three curves at the triple point are also different. The difference in the slopes of the tangents of the solid-vapour (hoar frost line), and the liquid-vapour (steam line) curves of water (Fig. 39) is... 

Appearance of semi-crystaUine polymer films changes during cooling from transparent to hazy at a point in the bubble called the frost line. Local unevenness in the film can be overcome by rotating the die or the haul-off and wind-up gear. The film has to be cooled down well below T or... 

Solution. Because the frost line is four feet below grade, the foundation will be six feet deep with the top 1 foot above grade, making the foundation bottom five feet below grade or one foot below the frost line. 

Once the plant location area and plot plans have been chosen, as explained in Chaps. 5 and 7, the specific site must be selected and developed for installation of structures. Preliminary exploration of the subsurface conditions should be done prior to purchase of a piece of land, since foundation construction may be abnormally high if the bearing load of the underground strata is poor, even though the surface conditions appear satisfactory. Topographical maps of the site to establish plant grades and excavation, together with transportation facility locations, frost-line, and water-table information, are other important site data required. Some detailed aspects of these factors will be presented next. 

The foundations should also be as wide as the tank, built below the frost line, and of a size dependent on the load. The load is a dead load,... 

Concrete foundations, both monolithic and separate piers, must extend below the frost line when on the ground. 

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