Pipes/piping fittings materials

Push -on joints (Fig. 10-137) require diametral control of the end of the pipe. They are used for brittle materials. Pipe, fittings, and valves are furnished with the bells cast on one or more ends. Considerable force is required to push the spigot through the O ring this is reduced by the extension on the O ring, which causes the friction of the pipe to elongate the cross sec tion of the main portion of the O ring. 

Chemical-Porcelain Pipe Made of dense, nonporous material and fired at 1230°C (2250°F), chemical-porcelain pipe, fittings, and valves are inert to all acids except hydrofluoric but are not usually recommended for alkalies. Surfaces, except when ground for gasketing, are usually glazed for easy cleaning. Working pressures of 0.3 to 0.7 MPa (50 to 100 Ibftin") are recommended for valves and piping. Temperatures of 200°C (400°F) or more can be used, but sudden thermal shocks must be avoided. 

Piping. Specify materials—stainless steel has numerous advantages. Specify welded construction and the minimum use of fitting. Tape-type thread lubricants should be avoided. 

The coefficient of hnear expansion of this alloy in the temperature range of 21 to 100°C (70 to 212°F) is 12.2 x l(r /°C (6.8 x 10- /°F), which is slightly above that of cast iron (National Bureau of Standards). Since this material has practically no elasticity, the need for expansion joints should be considered. Connections for flanged pipe, fittings, valves, and pumps are made to ASME B16.1, Class 125. 

Gasoline and kerosene rerunning was accomplished primarily in horizontal batch shell stills heated by direct firing or internal steam coils and surmounted by a vertical rectification column with partial condensers to supply reflux. The rectifying column in some installations was packed with iron rings, pipe fittings, earthware crocks, tin cans, or any suitable material readily available. In other units a fairly common type of column was the Heckmann bubble cap tower. 

Whilst carbon and stainless steels are commonly used materials of construction, increasing use is being made of non-metallic and rubber lined equipment. The selection of the material of construction should take into account the cases of the worst process conditions that may occur under foreseeable conditions and should be applied to all components including valves, pipe fittings, instruments and gauges. Both composition (e.g., chlorides, moisture) and temperature deviations can have a significant direct effect on the rate of corrosion. The operator should demonstrate that procedures are in place to ensure that potential deviations in process conditions such as fluid temperature, pressure and composition are identified and assessed in relation to the selection of materials of construction for piping systems. 

The cost of building a pipeline is usually divided into four categories materials (line pipe, fittings coatings, cathodic protection, etc), right-of-way... 

Standard specification for polyethylene pipe and fitting materials... 

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