Pipes copper

Not all elements of the industrial thermocouple need to be wine. For example, if a copper pipe contains a flowing fluid whose temperature is to be measured, a constantan wine attached to the pipe will form a T, or copper—constantan, thermocouple. Such arrangements ate difficult to caUbrate and requite full understanding of the possible inherent problems. For example, is the copper pipe fully annealed Homogeneous Pure, or an alloy Many ingenious solutions to specific measurement problems ate given in Reference 6. 

Threadless copper pipe, thinner than ASTM B42, is available with dimensions as in Table 10-34. Solder-end fittings similar to ANSI B16.15 screwed fittings and solder-end valves are used with this pipe. 

Copper pipe is attacked by water originating in granite substrata, and for this reason red-brass pipe per ASTM B43 with red-brass screwed or solder-end fittings is sometimes used in its place. 

Copper-silicon alloy (96 percent cooper, 3 percent silicon, 1 percent manganese), per ASTM B315, is furnished as seamless pipe and welding fittings in Schedule 10 and regular and extra-strong copper pipe thicknesses. It is easier to weld than copper. 

Copper and copper alloy Seamless pipe and tubing Copper pipe B42 31 Drawn 102, 120, 122 i/f -2, inclusive 45.0 40.0 9, 27 -325... 

Figure 8.8 Severe grooving on the internal surface of a copper pipe carrying condensate. Grooves were cut by condensing vapors running down pipe walls. Note the vivid blue corrosion products and deposits near the bottom.

Figure 8.10 A large, ragged perforation in a region of severe internal wastage on a copper pipe. Corrosion was caused hy ammonia-containing condensate.

A higher content of AI2O3 and SiOj is critical for the composition of the protective films in the tubing, assuming the water contains silicates or silicic acid. The protective films have a maximum thickness of 1.5 mm and cannot grow further. The corrosion process can be stopped even in copper pipe networks with type I pitting [21] by providing a reaction tank with impressed current aluminum anodes. 

Tinning of copper piping or components is a good approach toward minimizing galvanic action between dissimilar metals. 

Brazolet is esignei jr use wi h 1 I brass or copper piping or copper tubing. 

Rolled, molded or cut to shape as annular cylinders for the insulation of pipes. Pipe sections are made in one or two segments but occasionally in three or four. Sizes are available for most steel and copper pipes of up to approximately 1120 mm outside diameter. 

Copper pipe and tubing are sometimes used for fluid power lines. Copper has high resistance to corrosion and is easily drawn or bent. However, it is unsatisfactory for high temperatures and has a tendency to harden and break due to stress and vibration. 

Copper and its alloys in certain fresh waters give rise to a form of localised attack that is referred to as nodular pitting in which the attacked areas are covered by small mounds or nodules composed of corrosion products and of CaC03 precipitated from the water. This is a serious problem in view of the extensive use of copper pipes and tanks for water supplies, and in aggressive water these may perforate in a relatively short time. 

Lucey examined a number of examples of pitting of copper pipes and tanks from hard water districts, and found that there was no more calcium carbonate scale deposited around the pits than on other parts of the metal surface. There was, however, a large amount of CaCOs in the mound... 

Considerations such as these can lead to unexpected problems where waters are mixed, either at a treatment works or in a tidal zone within a distribution network into which two sources are fed separately. Within the author s experience, problems of an erosion attack on copper pipe have occurred at fittings, especially where the ends of the copper tube have been belled out to meet the requirements of the bye-laws for underground pipe, with mixtures of waters that were satisfactory when supplied separately. 

Gilbert, P.T., Dissolution by Fresh Waters of Copper from Copper Pipes , Proc. Soc. Water Treatment and Examination, 15, 3, 165 (1966)... 

In de-aerated conditions, for instance in most central heating systems, little if any attack on copper occurs . As far as drinking waters are concerned, copper is not classified as a toxic substance or hazardous to health. To avoid any difficulties due to unpalatability, the maximum continuous copper content should not exceed 10 p.p.m., with a limit of 3 p.p.m. in water after standing overnight in copper pipes. A review of the subject by Grunau makes reference to 394 published papers. 

Solders are anodic to copper, but soldered joints in copper pipes are widely used without trouble for cold supply waters possibly corrosion is restricted by the deposition of cathodic carbonate scales and the formation of insoluble lead compounds. Hot supply waters tend to be more aggressive and, where these are involved, it is wise to tin any copper which has a soldered joint. Electrolytes of high conductivity such as sea-water will also attack soldered joints in copper. 

Little information is available on the performance of copper and of copper alloys in contact with concrete, but concrete sometimes contains ammonia, even traces of which will induce stress-corrosion cracking of copper pipe. The ammonia may be derived from nitrogenous foaming agents used for producing lightweight insulating concrete. 

Copper pipes For plumbing above ground, copper is supplied in both half-hard and hard conditions. It has sufficient strength to require only few supports, and can be bent cold, in the small sizes, either by hand or with a portable bending machine. Copper is also supplied in the fully soft condition in coils for laying underground, for heating-panels, etc. 

Secondly, under certain conditions copper may suffer intense localised pitting corrosion, leading sometimes to perforation of the tube, in quite a short time. This form of attack is not common and depends on a combination of unusual circumstances, one of which is the possession by the tube of a fairly, but not entirely, continuous film or scale that is cathodic to the copper pipe in the supply water this can set up corrosion at the small anodes of bare copper exposed at faults or cracks in the film. Carbon films give rise to such corrosion, but since 1950, when the importance of carbon films was... 

Stainless steels Thin-walled stainless steel (Fe-18Cr-8Ni) tubes are now frequently used for domestic installations in place of copper pipe . Care is required, however, in the design of stainless steel equipment for use in waters with a high chloride content, or where the concentration can increase, since pitting attack may occur. It may also be susceptible to failure by stress-corrosion cracking under certain conditions. 

The calcium hypochlorite or sodium dichloroisocyanurate used to disinfect swimming pools also bleaches hair, although contrary to popular belief it does not turn the hair green. It simply allows the green copper sulfate from the water to show up in the hair. The copper sulfate comes from the reaction of the copper pipes in the plumbing to the sulfuric acid used to neutralize the alkalies in the chlorination chemicals. 

According to EPA s National Compliance Report for calendar year 1996 (EPA 1998g), the vast majority of people in the nation received water from systems that had no reported violations of the maximum contaminant level and treatment technique requirements or significant monitoring and reporting requirements. Lead has a maximum permissible level of 15 pg/L delivered to any user of a public water system. Lead and copper are regulated in a treatment technique that requires systems to take tap water samples at sites with lead pipes or copper pipes that have lead solder and/or are served by lead service lines. The water system is required to take treatment steps if the action level (15 pg/L for lead) is exceeded in more than 10% of tap water samples. For calendar year 1996, nearly 6 million people in the United States were served by community water systems that reported maximum contaminant level and treatment technique violations of the Lead and Copper Rule (EPA 1998g). 

Crystalline ammonium perchlorate ignited in contact with hot copper pipes. 

The action of certain metals (e.g., copper) on unsaturated rubbers, primarily natural rubber, is to catalyse the oxidative degradation of the polymer. The metal must be in an ionic form, i.e., straightforward contact with the metal such as a seal with a copper pipe will not promote such degradation. 

Silver is usually found in extremely low concentrations in natural waters because of its low crustal abundance and low mobility in water (USEPA 1980). One of the highest silver concentrations recorded in freshwater (38 pg/L) occurred in the Colorado River at Loma, Colorado, downstream of an abandoned gold-copper-silver mine, an oil shale extraction plant, a gasoline and coke refinery, and a uranium processing facility (USEPA 1980). The maximum recorded value of silver in tapwater in the United States was 26 pg/L — significantly higher than finished water from the treatment plant (maximum of 5.0 pg/L) — because of the use of tin-silver solders for joining copper pipes in the home, office, or factory (USEPA 1980). 

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