Reducers, pipe

Practical applications of the presented algorithm has been done on corrosion monitoring in the pipe system of a power plant. These examples were obtained from a reducing pipe fitting after... 

Fig. 5 Erosion pit inside a reducing pipe fitting, projection technique at 160 kV, profile plot with optical densities of the digitised film. The varying background caused by the geometrical set-up prevents a wall thickness calibration as in fig. 4...

CJd of valve when installed between pipe reducers (pipe dia. 2 x valve dia.). 

Davenport [1] has listed more than 60 major leaks of flammable materials, most of which resulted in serious fires or unconfined vapor cloud explosions. Table 9-1, derived from his data, classifies the leak by point of origin and shows that pipe failures accounted for half the failures— more than half if we exclude transport containers. It is therefore important to know why pipe failures occur. Following, a number of typical failures (or near failures) are discussed. These and other failures, summarized in References 2 and 3, show that by far the biggest single cause of pipe failures has been the failure of construction teams to follow instructions or to do well what was left to their discretion. The most effective way of reducing pipe failures is to ... 

This system is similar to a cold oil ring main but includes provision for heaters in the circuit to maintain oil temperature between minimum handling and atomizing levels. This provides a reduction in oil viscosity and reduces pipe friction. The circulation temperature of the oil should... 

When a pump is taking its suction from a tank, it should be located as close to the tank as possible in order to reduce the effect of friction losses on the NPSH available. Yet the pump must be far enough away from the tank to ensure that correct piping practice can be followed. Using a larger diameter line to limit the linear velocity to a level appropriate to the particular liquid being pumped can usually reduce pipe friction. Many industries work with a maximum velocity of about 5 feet per second, but this is not always acceptable. 

Construct the reduced pipe network corresponding to the topological graph of the worst-case state. 

Remove all unsatisfactory pipes from the reduced pipe network. Go to stage 1, step 2. 

Valve flow coefficient Cv = Cj x d2 (d = valve dia., in.) fCv/d2 of valve when installed between pipe reducers (pipe dia. 2 x valve dia.)... 

Figure 2 Reduced flowsheet of the experimental setup. The mass-flow controllers, the three-way valves in the oxidizing and reducing pipes, the multiple-way valve GC and the temperature of the reactor are all computer-controlled.

Fuel cell pressurization is typical of many optimization issues, in that there are many interrelated factors that can complicate the question of whether to pressurize the fuel cell. Pressurization improves process performance at the cost of providing the pressurization. Fundamentally, the question of pressurization is a trade-off between the improved performance (and/or reduced cell area) and the reduced piping volume, insulation, and heat loss compared to the increased parasitic load and capital cost of the compressor and pressure-rated equipment. However, other factors can further complicate the issue. To address this issue in more detail, pressurization for an MCFC system will be examined. 

Land costs, resulting from much higher production capacity and/or number of products per unit of manufacturing area Other investment costs, resulting from cheaper, compact equipment, reduced piping, reduced civic works, integrated processing units, etc. 

Usui, H. Itoh, T. Saeki, T. On pipe diameter effects in surfactant drag-reducing pipe flows. Rheol. Acta 1998, 37, 122-128. 

Seal leaking conduits end/or reduce piping along conduits Penetrallon grouting Compaction grouting... 

Effect of Reduced Pipe Wall Thickness Significant problems occur in older transmission pipes made from cast iron and ductile iron, as the wall thickness is reduced by corrosion until a leak occurs. Problems in newer iron pipes are similar to those found in older iron pipes, but occur after shorter time periods because of decreased wall thickness. Therefore, an effective corrosion control method is the selection of thicker wall pipe to provide a larger corrosion tolerance to wall thinning. Expensive thicker wall pipe will be cost-effective because of its long life and low need for maintenance. 

In pipe systems on the platform, the most severe corrosion attacks have been found between the wellhead and the first-stage separator, where water is precipitated, and where pressure, temperature as well as flow velocity are highest [8.29]. To a great extent, the attacks are localized in and at welds, in pipe joints, bends, and at places with reduced pipe diameter. (In many cases the attacks at welds could have been avoided by proper selection of welding consumables.) When the water content exceeds a critical level, the attacks become more severe. This is probably the reason for increased corrosion when the producing wells get older (the content of water increases with time due to water injection). 

The valve system is for controlling the direction of the hydraulic fluid flow, the hydraulic pressure, or the sequence of events. The valves are electrically solenoid operated or hydraulically operated. In most modern presses, the valves are cartridge type and are manifold mounted to reduce piping and potential leaks. Cartridge valves have greatly simplified hydraulic circuit design by their manifold... 

It is desirable to obtain the result of statistical analysis of the digitized data for more detailed understanding of turbulence mechanism in a drag reducing pipe flow. Thus, in this work, we attempted to give a more quantitative analysis including the skewness factor and the flatness factor. 

Achia, B. U. and D. W. Thompson, "Structure of Turbulent Boundary in Drag-Reducing Pipe Flow", J. Fluid Mech., 81, (1977) 439-464... 

ACHIA B.U. THOMPSON D.W. (1974) Laser holographic measurements of wall turbulence structures in drag reducing pipe flow. Proc. Int. Conf. on Drag Reduction Cambridge A2, 23-40 (1977) Structure of the turbulent boundary in drag reducing pipe flow JFM 81, 439-64... 

---