SMU Building Drainage Systems - Pipes, fittings, clamps and fittings are world-recognized high-quality cast iron products. The PAM SMU Building Drainage Piping System provides clever modular piping components that can be adapted to a wide range of field conditions; a wide range of products to meet different needs and ease of installation; and a full range of PAM clamp fittings to ensure connection to cast iron and other material tubing.