Materials ductile iron

Listed metallic materials Ductile iron, malleable iron. Carbon steel, ASTM A36, ASTM A283 1. No additional requirements. 1. Shall not be used. 

HBI has been successfully melted in cupolas (hot or cold blast), induction furnaces (coreless or channel), and electric arc furnaces. It can be a valuable charge material for ductile and malleable irons as well as steel. It is of particular value in making ductile iron castings because of its very low residual element content. 

As an approximation, 50% of the Hst price should be added to account for auxiUaries such as motor, seal, baseplate, and coupling. Furthermore, the material upgrade from ductile iron constmction to stainless steel roughly doubles the price. Pump manufacturers use price bookmultiphers, eg, discounts, to arrive at a selling price. These vary, but as an estimate, a 30% discount is reasonable. U.S. pump manufacturers include the following. 

Austenitic ductile iron, ASTM A571 4(3. No ad(htional requirements. 4b. Wel(hng not permitted. 4. The material shall be impact-tested. This material shall not be used at design minimum temperatures lower than —196 C (—320 F). Wel(hug is not permitted. 

Part UHT also contains more stringent details for nozzle welding that are required for some of these hi -strength materials. Part UCI has rules for cast-iron construction. Part UCL has rules for welded vessels of clad plate as lined vessels, and Part UCD has rules for ductile-iron pressure vessels. 

The most common material used in cylinder construction is cast iron for the larger, low-pressure cylinders and steel for the smaller, high pressure cylinders. In some cases, nodular or ductile iron can be used in lieu of cast iron. For hydrocarbon service, steel is most desirable, although not universally available. 

Materials acceptable for underground piping use include ductile iron, fiberglass-reinforced epoxy plastic, polyethylene, polyvinyl chloride, reinforced concrete, and carbon steel. Plastic pipes are not acceptable in areas subject to solvent exposure. 

Chemical pumps are available in a variety of materials. Metal pumps are the most widely used. Although they may be obtained in iron, bronze, and iron with bronze fittings, an increasing number of pumps of ductile-iron, steel, and nickel alloys are being used. Pumps are also available in glass, glass-lined iron, carbon, rubber, rubber-lined metal, ceramics, and a variety of plastics, such units usually being employed for special purposes. 

In the production of ductile iron, calcium carbide is often used as a desulfurizing agent. When added to the iron, it reacts with the sulfides and forms calcium sulfide. This material floats on the surface of the molten iron, where it is skimmed off the surface and placed in a hopper. Since excess carbide is employed to ensure removal of the sulfur, the resulting slag contains high levels of unreactive carbide and must be handled as a reactive waste. 

In gray iron, most of the contained carbon is in the form of graphite flakes, dispersed throughout the iron. In ductile iron, the major form of contained carbon is graphite spheres, which are visible as dots on a ground surface. In white iron, practically all contained carbon is combined with iron as iron carbide (cementite). a very hard material. In malleable iron, the carbon is present as graphite nodules. High-alloy irons usually contain an alloy content in excess of 3%. 

After several years of operation, conditions warranted the replacement of a pump bowl. The plant warehouse did not stock spare ductile iron pump bowls and none were accessible. A resourceful maintenance supervisor realized that there were a few other large pumps within the plant and they located one. Unfortunately, they chose a cast iron pump bowl which is very desirable for certain sodium chloride (table salt) brine services, but it is totally unsuited for large volumes of highly flammable materials. 

Hot-melt spray adhesives will bond successfully carpets, fabrics, laminating panels, metals (both painted and unpainted), and both polyethylene and polypropylene film and sheet. Two important commercial uses at the time of writing are bonding sleeves of low-density polyethylene to ductile iron pipes and bonding sound-deadening materials and carpets to the floors of motor cars. 

The electric furnace melting of steel scrap rather than cupola melting is a trend that will probably continue resulting in increasing need for recarburisers. And as the ductile iron segment of the foundry industry grows, so will the demand for consistent materials that allow improved process control. 

There was no indication of pipe failure due to the defects of the pipe material. With the exception of one example corrosion of both ductile iron and cast iron pipes from the water side was negligible. 

Metallurgy 22 Cast iron should not be used for flammable or hazardous service. The minimum metallurgy for centrifugal pumps for hazardous or flammable materials is cast ductile iron, type ASTM A 395, having an ultimate tensile strength of about 60,000 psi. 

The upgraded bimodal high density PE provides certain advantages. Its excellent ductility enables PE pipe to survive an earthquake better than more rigid materials such as PVC or ductile iron. They have a slow... 

Don t use cast iron for flammable or hazardous service unless there is no other choice. In very few cases, only cast iron is available. This is true for large double-suction water pumps used by municipalities where types other than cast iron are not readily available. The minimum metallurgy for centrifugal pumps for hazardous or flammable materials is cast ductile iron, type ASTM A 395, having an ultimate tensile strength of 60,000 psi. This metal is not brittle at ordinary temperatures. Often, special alloys are required because of corrosion. In no case should brittle materials be used for a pump if other choices are available. 

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