__________ joint is usually used for joining cast iron pipes mostly used for temporary pipelines, where it may be necessary to dismantle & reassemble the pipeline very frequently.

ANS:B - Flanged

Flanged joints are commonly used in piping systems for joining pipes, valves, fittings, and other components. Here's an explanation of flanged joints:

1. Components: In a flanged joint, the end of each pipe is equipped with a flange, which is a flat, circular disc with uniformly spaced holes around its perimeter. These flanges are typically made of steel or other suitable materials.
2. Assembly: To join two pipes using a flanged joint, the flanged ends of the pipes are aligned so that the bolt holes in each flange match up. A gasket, usually made of rubber or other resilient material, is placed between the mating flanges to provide a seal.
3. Fastening: Once the pipes are aligned and the gasket is in place, bolts are inserted through the holes in the flanges and tightened with nuts. This compresses the gasket between the flanges, creating a tight seal that prevents leaks.
4. Advantages: Flanged joints offer several advantages, including ease of assembly and disassembly, suitability for high-pressure and high-temperature applications, and compatibility with various piping materials.
5. Applications: Flanged joints are commonly used in industries such as petrochemical, oil and gas, water treatment, and power generation, where reliable sealing and easy maintenance are essential.