What type of joint is typically used for joining hubless cast iron pipes?

• A. Mortar joint
• B. Compression joint
• C. Welded joint
• D. Soldered joint

Answer: (B)

The use of a compression joint for joining hubless cast iron pipes is commonplace due to its effective sealing and mechanical properties. A compression joint utilizes a rubber gasket that fits inside a bell-shaped end of the pipe, creating a watertight seal when tightened. This design is particularly well-suited for hubless cast iron pipes, which lack the external bell or hub feature traditionally found in standard cast iron pipe installations.

This method not only allows for easy assembly and disassembly, which is valuable during maintenance or repairs, but it also accommodates any slight misalignments that may occur during installation without compromising the integrity of the connection. The mechanical gripping of the gasket under compression ensures a reliable and leak-free joint, making it ideal for various plumbing and drainage applications where hubless cast iron pipes are employed.