Jacuzzi is a company that produces whirlpool bathtubs and spas. Its first product was a bath with massaging jets. The trademarked Jacuzzi name is commonly used to refer to any bath with water jets, and can thus be considered a genericized trademark.
Johnni-bolts are closet bolts, used to mount toilet bowls to the closet flange. These bolts are installed into slots in a closet flange, then a wax gasket is added and toilet bowl is set in place and johnni bolts are tightened down. They get cut and capped to finalize project.
A joint runner is a colar like device made out of an incombustible material (such as asbestos), that keeps the molten lead poured in the bell of a joint in place while sealing a joints in cast iron pipe.
JTU stands for Jackson Turbidity Unit it is a quantitative unit of turbidity originally based on the comparison of a liquid (such as water) with a suspension of a specify type of silica, using the turbidity measure in a Jackson Candle Turbidimeter.