When joining cast-iron and coated steel pipes, what is the recommended method?

When joining cast-iron and coated steel pipes, the recommended method is mechanical fitting. This technique is preferred because it allows for a strong connection without the need for heat, which can potentially damage the coating of the steel pipe or affect the integrity of the cast-iron pipe. Mechanical fittings are designed to create a secure, leak-proof seal by using bolts, clamps, or other mechanical means, making them suitable for applications where differing materials are involved and where flexibility or movement may be expected.

Using other methods such as soldering, welding, or adhesive bonding can pose difficulties. Soldering and welding involve heat that can compromise the integrity of the pipe materials or their coatings. Adhesive bonding may not provide the necessary strength or durability for the pressure and conditions typically found in distribution systems. Therefore, mechanical fitting is the most reliable and effective method for joining these two types of pipes.