While I'm do an audit to store department such as material, equipment and consumable, I'll try to do a post for this Piping & Fabrication blog and I hope this will keep our knowledge increase.
Cast Pipe
Cast-Iron Pipe. There are four basic types of cast iron: white iron, gray iron, ductile iron, and malleable iron. White iron is characterized by the prevalence of carbides which impart high compressive strength, hardness, and resistance to wear. Gray cast iron has graphite in the microstructure, giving good machinability and resistance to wear and galling. Ductile iron is gray iron with small amounts of magnesium or cesium which bring about nodularization of the graphite, resulting in both high strength and ductility. Malleable iron is white cast iron which has been heat-treated to provide for ductility.
Cast-iron pipe is extensively used for underlying water, sewage, and gas distribution systems because of its long life expectancy. Specifications for this pipe can be found under Federal SpecificationW-W-P-421b-Pipe, Cast Iron, Pressure (for Water and Other Liquids). Cast-iron pipe is produced from four processes: vertical pit casting, horizontal casting, centrifugal sand mold casting, and centrifugal metal mold casting.
Vertical Pit Process. The vertical pit process for producing pipe requires a sand mold formed into a pipe pattern of the outer surface of the pipe, into which a separately made core is placed. The molten iron is poured into the vertical annulus between the outer mold and the core. American Standard Specifications for Cast Iron Pit Cast Pipe for Water or Other Liquids are available in ASTM Specification A 377. Pit-cast pipe specifications for the gas industry may be found in American Gas Association (AGA) Standards for Cast Iron Pipe and Special Castings. ASTM Designation A142 provides specifications for pit-cast culvert pipe.
Horizontal Process. In the horizontal cast-iron pipe process, horizontal outer molds are made in halves, with a core formed around a perforated horizontal bar. After the top half is placed on the bottom half, the molten iron is introduced in a manner preventing ladle slag from entering the mold.
Centrifugally Cast-Iron Pipe. There are two types of centrifugal casting machines-horizontal and vertical. Pipe is most commonly produced in the horizontal machine. The centrifugal castings are formed after molten metal is poured into a rotating mold. The mold continues its rotation until solidification of the metal is complete, after which the casting is removed. Molds can be made of sand or, for permanent molds, graphite, carbon, or steel. The centrifugal casting process provides a means of producing high-quality castings which are defect-free due to the absence of shrinking. These castings cool from the outside to the inside, providing a desirable directional solidification which results in cleaner and denser castings than those resulting from static casting methods.
Cast-Steel Pipe. Cast-steel pipe is produced by either static or centrifugal casting processes. In the horizontal centrifugal casting machine, the molten steel is introduced into the rotating mold of sand, ceramics, or metal. Centrifugally cast pipe can be obtained in sizes up to NPS 54 (DN 1350). Application of this pipe can be found in paper mill rolls, gun barrels, and high-temperature and pressure service in refineries (temperatures above 1000_F or 538_C). This process is also used for high-nickel and high-nickel alloy pipes.
Cold-Wrought Steel Pipe. Centrifugally cast stainless steel pipe can be cold expanded subsequent to casting by internally applied pressure to form cold-wrought pipe. The process, called hydroforging, applied to austenitic stainless steels provides for recrystallization and grain refinement of the centrifugally cast material grain structure.
Cast-Iron Pipe. There are four basic types of cast iron: white iron, gray iron, ductile iron, and malleable iron. White iron is characterized by the prevalence of carbides which impart high compressive strength, hardness, and resistance to wear. Gray cast iron has graphite in the microstructure, giving good machinability and resistance to wear and galling. Ductile iron is gray iron with small amounts of magnesium or cesium which bring about nodularization of the graphite, resulting in both high strength and ductility. Malleable iron is white cast iron which has been heat-treated to provide for ductility.
Cast-iron pipe is extensively used for underlying water, sewage, and gas distribution systems because of its long life expectancy. Specifications for this pipe can be found under Federal SpecificationW-W-P-421b-Pipe, Cast Iron, Pressure (for Water and Other Liquids). Cast-iron pipe is produced from four processes: vertical pit casting, horizontal casting, centrifugal sand mold casting, and centrifugal metal mold casting.
Vertical Pit Process. The vertical pit process for producing pipe requires a sand mold formed into a pipe pattern of the outer surface of the pipe, into which a separately made core is placed. The molten iron is poured into the vertical annulus between the outer mold and the core. American Standard Specifications for Cast Iron Pit Cast Pipe for Water or Other Liquids are available in ASTM Specification A 377. Pit-cast pipe specifications for the gas industry may be found in American Gas Association (AGA) Standards for Cast Iron Pipe and Special Castings. ASTM Designation A142 provides specifications for pit-cast culvert pipe.
Horizontal Process. In the horizontal cast-iron pipe process, horizontal outer molds are made in halves, with a core formed around a perforated horizontal bar. After the top half is placed on the bottom half, the molten iron is introduced in a manner preventing ladle slag from entering the mold.
Centrifugally Cast-Iron Pipe. There are two types of centrifugal casting machines-horizontal and vertical. Pipe is most commonly produced in the horizontal machine. The centrifugal castings are formed after molten metal is poured into a rotating mold. The mold continues its rotation until solidification of the metal is complete, after which the casting is removed. Molds can be made of sand or, for permanent molds, graphite, carbon, or steel. The centrifugal casting process provides a means of producing high-quality castings which are defect-free due to the absence of shrinking. These castings cool from the outside to the inside, providing a desirable directional solidification which results in cleaner and denser castings than those resulting from static casting methods.
Cast-Steel Pipe. Cast-steel pipe is produced by either static or centrifugal casting processes. In the horizontal centrifugal casting machine, the molten steel is introduced into the rotating mold of sand, ceramics, or metal. Centrifugally cast pipe can be obtained in sizes up to NPS 54 (DN 1350). Application of this pipe can be found in paper mill rolls, gun barrels, and high-temperature and pressure service in refineries (temperatures above 1000_F or 538_C). This process is also used for high-nickel and high-nickel alloy pipes.
Cold-Wrought Steel Pipe. Centrifugally cast stainless steel pipe can be cold expanded subsequent to casting by internally applied pressure to form cold-wrought pipe. The process, called hydroforging, applied to austenitic stainless steels provides for recrystallization and grain refinement of the centrifugally cast material grain structure.
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