What is a common use for molten lead in plumbing?

Molten lead has historically been used in plumbing primarily for creating strong seals. This technique, known as lead soldering, involves melting lead and using it to fill joints and seams in pipes, particularly in older plumbing systems. The properties of lead provide a durable and watertight seal that can withstand the pressures of water flow and thermal expansion, making it effective for both drainage and supply lines.

While lead has been utilized for several purposes due to its malleability and low melting point, modern plumbing has largely moved away from using it, mainly due to health concerns associated with lead exposure. Nevertheless, in the context of historical practices, the use of molten lead for sealing joints is well-documented and recognized for its effectiveness in ensuring leak-proof connections in plumbing applications.

Other options, such as coating pipes for insulation, enhancing flexibility, or preventing corrosion, do not accurately reflect the primary applications of molten lead in plumbing. Lead is not used to provide insulation properties nor does it enhance pipe flexibility; instead, other materials like insulation foam or rubber are employed for those specific functions. Additionally, the contemporary focus on preventing corrosion involves materials like copper and certain types of plastic rather than lead.