Pipe, aluminum brass alloy

It will also be possible by relatively minor piping changes to convert the forward-feed evaporator to backward feed, which might be more favorable if the calcium sulfate scale problem can be solved. Except for tubes, pump shaft sleeves, impellers, etc., the plant will be built exclusively of steel and cast iron. Tube materials will be evaluated by tubing different evaporator effects and heat exchangers with steel, admiralty metal, aluminum brass, and 90/10 cupronickel. The copper alloy tubes will be used exclusively in the final condenser and in the few heat exchangers that are in contact with nondeaerated sea water. 

In 1797, Joseph Barmah patented the first extrusion process for making lead pipes. The metal used to be preheated and ram was hand-driven. In 1820, Thomas Burr built the first hydraulic power press that was to extrude lead pipes (Sheppard 2013). The process was called squirting. By the end of nineteenth century, the extmsion methods were also in use for copper and brass alloys. Alexander Dick invented a hot extrusion process for nonferrous metals in 1894. North America has its first aluminum extrusion process in 1904. In 1950s, Sejounet introduced molten glass as lubricant in extmsion process. 

ALkylamines are corrosive to copper, copper-containing alloys (brass), aluminum, 2inc, 2inc alloy, and galvani2ed surfaces. Aqueous solutions of aLkylamines slowly etch glass as a consequence of the basic properties of the amines in water. Carbon or stainless steel vessels and piping have been used satisfactorily for handling aLkylamines and, as noted above, some aLkylamines can act as corrosion inhibitors in boiler appHcations. 

Methyl bromide, when dry (<100 ppm water), is inert toward most materials of constmction. Carbon steel is recommended for storage vessels, piping, pumps, valves, and fittings. Copper, brass, nickel, and its alloys are sometimes used. Aluminum, magnesium, zinc, and alloys of these metals should not be used because under some conditions dangerous pyrophoric compounds may be formed. Many nonmetallic materials are also useful for handling methyl bromide, but nylon and polyvinyl chloride should be avoided. 

Chlorosulfuric acid attacks brass, bronze, lead, and most other nonferrous metals. From a corrosion standpoint, carbon steel and cast Hon are acceptable below 35°C provided color and Hon content is not a concern. Stainless steels (300-series) and certain aluminum alloys are acceptable materials of constmction, as is HasteUoy. Glass, glass-lined steel, or Teflon-lined piping and equipment are the preferred materials at elevated temperatures and/or high velocities or where trace Hon contamination is a problem, such as in the synthetic detergent industry. 

Appendix A contains a materials selection guide for aerated freshwater systems. As indicated in Note 27 of Appendix A, in freshwater systems, admiralty brass should be limited to a maximum pH value of 7.2 from ammonia and copper-nickel alloys and should not be used in waters containing more sulfides than 0.007 mg/L The materials selection guide is also satisfactory for seawater, although pump cases and impellers should be a suitable duplex stainless steel or nickel-aluminum-bronze (properly heat treated). Neoprene-lined water boxes should be considered. For piping, fiber-reinforced plastic (up to 150 psi [1,035 kPa] operating pressure) and neoprene-lined steel should also be considered. Titanium and high-molybdenum SS tubes should be considered where low maintenance is required or the cost can be justified by life expectancy. 

E6.2. Predict whether or not galvanic corrosion will cause the following alloys to be subjected to leaching (i) carbon and carbon steel alloys in an oxidizing atmosphere, (ii) steel rivets in aluminum drain gutters, (iii) copper-nickel alloy in refinery condenser tubes, (iii) graphite fiber-reinforced aluminum composites, (iv) brass in water, (v) iron-chromium alloys, and (vi) carbon steel pipe in contact with the weld to stainless steel pipe. 

Corrosion caused by the connection of two or more different metals also occurs underground. This electrochemical corrosion cell is commonly referred to as bimetallic or galvanic corrosion. Typical examples include brass or bronze valves connected to steel or cast iron pipes and stainless steel fasteners coimected to steel or cast iron. These couplings of dissimilar metals will locally affect the corrosion rate. Aluminum can be severely corroded if directly connected to most other engineering alloys, such as steel, iron, copper, or stainless steel—dielectric isolation must be used. 

Piping made of brass, copper, or aluminum is sometimes used for special purposes. These metals have low melting points and thus have a high potential for failure if exposed to fire. Alloy materials are sometimes chosen for severe temperature or corrosion services. 

---