Piping materials

The presence of these acids in crude oils and petroleum cuts causes problems for the refiner because they form stable emulsions with caustic solutions during desalting or in lubricating oil production very corrosive at high temperatures (350-400°C), they attack ordinary carbon steel, which necessitates the use of alloy piping materials. 

The Research-Production Company (RPC) Zond (city of Ivano-Frankivsk) now is a well-known centre for development, fabrication and introduction of the technologies and methods of NOT of oil and gas equipment and tools Its experts developed and introduced the technologies and equipment which enables control of the drill pipes, especially their threaded joints, oil and gas equipment, sort out the pipes into groups by the strength and yield point of the pipes material, etc. 

Pipe-Wall Thickness. Once the design pressure and temperature have been established and the pipe material and size selected, the wall thickness is calculated using the appropriate section of the code. In rare cases, a thin pipe must be made thicker to withstand handling. Occasionally the thickness is affected by external loads or vibrations. All codes prescribe essentially the same design formula for metallic hoUow circular cylinders under internal pressure ... 

Supports. The spaciag of supports is governed by the hot allowable stress of the piping materials stabiUty, ia the case of large-diameter thin-wall pipe deflection to avoid sagging or pocketing and the natural frequency of the unsupported length to avoid susceptibiUty to undesirable vibration. 

Carbon steel is not normally a suitable piping material for concentrated sulfuric acid because of high corrosion rates in flowing acid. However, where temperatures and flow rates are low, heavy waU steel pipe is sometimes used for transferring product acid. 

Lead and Lead-Lined Steel Pipe Lead and lead-hned steel lipe have been essentially eliminated as piping materials owing to lealth hazards in fabrication and installation and to environmental objections. Lead has been replaced by suitable plastic, reinforced plastic, plastic-lined steel, or high-alloy materials. 

Plastic Pipe In contrast to other piping materials, plastic pipe is free from internal and external corrosion, is easily cut and joined, and does not cause galvanic corrosion when coupled to other materials. Allowable stresses and upper temperature limits are low. Normal operation is in the creep range. Fluids for which a plastic is not suited penetrate and soften it rather than dissolve surface layers. Coefficients... 

Displacement Strains The concepts of strain imposed by restraint of thermal expansion or contraction and by external movement described for metallic piping apply in principle to nonmetals. Nevertheless, the assumption that stresses throughout the piping system can be predic ted from these strains because of fully elastic behavior of the piping materials is not generally valid for nonmetals. 

The test shall be hydrostatic, using water, with the following exceptions. If there is a possibility of damage due to freezing or if the operating fluid or piping material would be adversely affected by water, any other suitable hquid may be used. If a flammable hquid is used, its flash point shall not be less than 50°C (120°F), and consideration shall be given to the test environment. 

Cascade coolers are a series of standard pipes, usually manifolded in parallel, and connected in series by vertically or horizontally oriented U-bends. Process fluid flows inside the pipe entering at the bottom and water trickles from the top downward over the external pipe surface. The water is collected from a trough under the pipe sections, cooled, and recirculated over the pipe sections. The pipe material can be any of the metallic and also glass, impeiMous graphite, and ceramics. The tubeside coefficient and pressure drop is as in any circular duct. The water coefficient (with Re number less than 2100) is calculated from the following equation by W.H. McAdams, TB. Drew, and G.S. Bays Jr., from the ASME trans. 62, 627-631 (1940). 

Use pipe material of construction which does not require lining... 

In recent years new ec]uipment has been invented, chemical processes, piping materials, valve designs, and new teehnologies not eonsidered when these formulas were developed with eold water in the 19th century. There is a need to measure the aetual losses onee an industrial plant is eommissioned and operations begin. I he authors of this book have developed a formula that permits the measurements of these losses in a live functioning system. Here it is ... 

The specific electrical resistances usually depend on the material and the temperature [31]. For the most important pipe materials these are (in 10 Q cm) ... 

Fluid Suggested Trial Velocity Pipe Material Fluid Suggested Trial Velocity Pipe Material... 

Figure 3. Relative roughness of pipe materials and friction factors for complete turbulence. ...

The main interest in polybut-1 -ene is in its use as a piping material, where the ability to use a lower wall thickness for a given pressure requirement than necessary with other polyolefins, together with the low density, can lead in some cases to economic use. The principal application is for small-bore cold and hot water piping (up to 95°C) for domestic plumbing. Current world-wide sales are of the order of 16-20X10 tonnes per annum. 

Provide permanent brazed or welded pipelines from the cylinders to near the points of gas use. Select pipe materials suitable for the gas and its application. Any flexible piping used should be protected against physical damage. Never use rubber or plastic connections from cylinders containing toxic gases. 

When applying low temperature requirements, one should consider safety valve and flare headers to be subject to "shock chilling" if they can be exposed to cold liquids released into the system. This includes flare headers from blowdown drums into which cold liquids are discharged. Where laterals of different piping material are combined, the material of the lower-temperature header is continued for the rest of the combined line, and is also extended back into the other lines for 6 m. 

N P Refinery will be responsible for the wiring and piping materials from the ignition panel to the bottom of the flare tip assembly. 

Cast iron piping materials shall not be used. 

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