Older radiators were made of cast iron and joined using which method?

Older radiators, particularly those made of cast iron, were typically joined using screw or push nipples. This method involved the use of threaded fittings where pipes or sections of the radiator would be connected securely by screwing them together. The design of cast iron radiators necessitated robust connections to endure high pressures and temperatures while distributing heat effectively.

The screw or push nipple method allowed for relatively easy assembly and disassembly of radiators, making it practical for maintenance and replacements. Additionally, cast iron's durability made it suitable for this joining technique, as the sturdy material could withstand the mechanical forces involved.

Other methods like welding and soldering are not commonly associated with the construction of cast iron radiators because the cast iron material does not lend itself well to these techniques. Welding requires high temperatures that can compromise the integrity of cast iron, while soldering typically applies to metals with lower melting points. Clamps, while useful for certain applications, are not a standard method for joining the heavy and rigid structure of cast iron radiator sections. Thus, screw or push nipples are the appropriate choice for connecting older cast iron radiators, ensuring a secure and reliable connection for effective heating.