Cast iron pipe发表评论(0)编辑词条

Cast iron pipe is a historical pipe which found widespread use as a pressure pipe

Cast iron pipe

 for transmission of water, gas and sewage, and as a water drainage pipe, during the 19th and 20th centuries. It comprises predominantly a gray cast iron tube and was frequently used uncoated, although later developments did result in various coatings and linings to reduce corrosion and improve hydraulics. Cast iron pipe was gradually superseded by ductile iron pipe, which is a direct development, with most existing manufacturing plants transitioning to the new material during the 1970’s and 1980’s. There is currently almost no new manufacture of cast iron pipe.

History
Early Use
The first use of cast iron pipe is not recorded. Cast iron tubes were first manufactured in the 14th century in Europe for cannon and it is presumed that similar tubes would have found use as water pipes at the same time, however, it was not until 1455 in Siegerland that the first officially recorded cast iron water pipe was produced for use in Dillenburg Castle (since destroyed).

The oldest extant water pipes date from the 17th century and were installed to distribute water throughout the gardens of the Chateau de Versailles. These amount to some 35km of pipe, typically 1m lengths with flanged joints. The extreme age of these pipes make them of considerable historical value. Following extensive refurbishment in 2008 by Saint-Gobain PAM, 80% remain original.

Manufacture
Vertically Cast
The first cast iron pipe was produced in horizontal molds which resulted in an uneven distribution of metal around the pipe circumference. In 1845, the first pipe was cast vertically and by the turn of the century, all pipe was manufactured to this method.

Centrifugally Cast
Subsequent to its invention by Dimitri Sensaud deLavaud, a French-Brazilian, in 1918, much cast iron pipe manufacture shifted to the dramatically different technique of centrifugal casting. Modern ductile iron pipe production continues to use this method of casting.

Standardization
The first standardization of cast iron water pipes in Britain occurred in 1917 with the publishing of BS 78. This standard specified a dimensionless nominal size, which approximately corresponded with the internal diameter in inches of the pipe, and four pressure classes, Class A, Class B, Class C and Class D, each with a specified wall thickness and outer diameter. It is noted that the outer diameter is identical between classes with the exception of sizes 12 to 27, where Classes A and B share one diameter and Classes C and D have another, larger diameter.

BS 78 was finally superseded when the U.K. harmonised with incompatible European standards, however, the specified outer dimensions continue to remain in effect (albeit in metric form) as the standard pipe outer diameter for ductile iron pipe in Australia and New Zealand through the descendant specification, AS/NZS 2280.
铸铁管　　

    用铸铁浇铸成型的管子。铸铁管用于给水、排水和煤气输送管线，它包括铸铁直管和管件。劳动强度小。按铸造方法不同，分为连续铸铁管和离心铸铁管，其中离心铸铁管又分为砂型和金属型两种。按材质不同分为灰口铸铁管和球墨铸铁管。柔性接口用橡胶圈密封，
　　连续灰口铸铁管的公称口径为75～1200毫米，采用承插式或法兰盘式接口形式；按功能又可分为柔性接口和刚性接口两种。直管长度有4米、5米及6米;按壁厚不同分LA、A和B三级。砂型离心灰口铸铁管的公称口径为200～1000毫米，有效长度有5米及6米；按壁厚不同分P、G两级。强度大、韧性好、管壁薄、金属用量少、能承受较高的压力，
　　球墨铸铁管与灰口铸铁管相比，强度大、韧性好、管壁薄、金属用量少、能承受较高的压力，有效长度有5米及6米；按壁厚不同分P、G两级。是铸铁管材的发展方向。
　　管与管之间的连接，采用承插式或法兰盘式接口形式；按功能又可分为柔性接口和刚性接口两种。柔性接口用橡胶圈密封，允许有一定限度的转角和位移，因而具有良好的抗震性和密封性，比刚性接口安装简便快速，按铸造方法不同，劳动强度小。