Cement line

Oil and Petrochemicals. There are a variety of uses for defoamers in oil recovery. They are used in some of the materials used in oil extraction, such as in drilling muds and cement lining, and also directly with the cmde oil itself. In its natural state cmde oil contains dissolved gases held by high reservoir pressure. When this Hve cmde oil is extracted and passed into the low pressure environment of a gas-oil separator, the dissolved gases are... 

Cement-Lined Steel Cement-hned steel pipe is made by lining steel pipe with special cement. Its use prevents pickup of iron by the fluid handled, corrosion of the metal by brackish water, and growth of tuberculation. Threaded pipe in sizes from to 4 in is stocked however, cement-lined pipe in sizes smaller than in is not considered practical for common use. 

The coefficients of expansion of iron and cement are nearly ahke. Table 10-39 gives dimensions of cement-lined pipe. 

TABLE 10-39 Cement-Lined Carbon-steel Pipe ... 

Crete piping systems can be lined with special salt-glazed vitrified-clay liner plates, joined with a die-cast aspnalt joint. Concrete pressure pipe is competitive with cement-lined ductile iron for underground plant water systems. 

Cement-lined iron or steel centrifugally applied — 150 140... 

Cement-lined iron or steel ccntrifiigally applied. 

Bone remodelling, which continues throughout adult life, is necessary for the maintenance of normal bone structure and requires that bone formation and resorption should be balanced. Bone remodelling occurs in focal or discrete packets know as bone multicellular unit (BMU). In this process, both bone formation and resorption occur at the same place so that there is no change in the shape of the bone. After a certain amount of bone is removed as a result of osteoclastic resorption and the osteoclasts have moved away from the site, a reversal phase takes place in which a cement line is laid down. Osteoblasts then synthesize matrix, which becomes mineralised. The BMU remodeling sequence normally takes about 3 months to produce a bone structure unit (Fig. 2). 

Smith, D. C., Ruse, D. N. Zuccolin, D. (1988). Some characteristics of glass ionomer cement lining materials. Canadian Dental Journal, 54, 903-8. 

Cement-Lined Carbon-Steel Pipe Cement-lined carbon-steel pipe is made by lining steel pipe with special cement. The cement lin-... 

Cement-lined pipe in sizes smaller than 1 Vk in is not generally recommended. Cement-lined carbon steel pipe can be supplied with butt-weld or flanged ends. Butt-welded construction involves the use of special joint grouts at the weld joint and controlled welding procedures. See Table 10-40. 

Figure 3. A pie-shaped section of an osteon. The osteonal canal is on the upper right, the cement line to the left. The osteonal canal is part of the vascular porosity (PV), the lacunae and the canaliculi are part of the lacunar-canalicular porosity (PLC) and the material in the space that is neither PV or PLC contains the collagen-apatite porosity (PCA).The three interfaces, the cement line, the cellular interface (IC) and the lacunar-canalicular interface are each indicated. The radius of an osteon is usually about 100 mm, and the long axis of a lacuna is about 15 mm. Using this information it should be possible to establish the approximate scale of the printed version of this illustration. Previously published in Cowin (1999).

A — Anode (from graphite platos), B — Diaphragm, K — Copper gauze cathode, L — Brine inlet, — Brine outlet (for saturation with salt), S — Fixing of electrode, St — Supports for diaphragm and cathode, Z — Cement lining of the frame. 

Erosion Similar to abrasion cutting in ductile metal fracture (of brittle material) very small chips or particles (e.g., impellers, propellers, fans) Reduce fluid velocity to eliminate turbulence select harder alloy (high chromium) hard coatings such as cement lined pipe, rubber lining... 

Only one case reported an increase of Al during drinking water distribution (also discussed in this paper), because Al leached from the cement lining of a water distribution pipe [17, 18]. 

Cement linings of drinking water distribution pipes should be reevaluated for their possible toxicological properties. 

A sulfur well consists of a casing and three concentric pipes reaching into the sulfurbearing strata. The outer 8- to 10-in. pipe carries 165°C water pumped into the formation to melt the sulfur. An inner cement-lined 3- to 6-in. pipe is used to transport the melted sulfur to the surface. Compressed air is passed through the 1-in. tube in the center to air lift the sulfur. Without the air lift the molten sulfur would rise only part way in the middle pipe. The compressed air produces a low-density sulfur froth that rises to the surface. 

The initial corrosion control system used in a crude unit is a desalter. Modern desalters separate oil and water electrostatically. The internals used to accomplish electrostatic separation are normally of a proprietary design. The vessel itself is usually carbon steel. The bottom is often cement lined to protect it from salt water corrosion. The payout on a desalter is difficult to establish. Desalters are normally used when the salt content of the crude exceeds 20 lb per 1,000 barrels (ptb). When high reliability of the unit is desired, crudes with salt contents of 8 to 10 ptb are desalted. When desalting is used, the target is 1 ptb or less. Fluctuations in salt content are particularly troublesome to the downstream equipment therefore, the desalter should be designed for the maximum anticipated salt content. 

MR0175, For carbon steeft the hardness limit shoiid be 200 Srlneil Rockwell B 95 see NACE Standard RP0472) p4] Avoid use of cement linings or Monel 400 for sour water. See Number 14 for corrosion allowance on carbon steel exposed to sour water. 

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