Which installation method is prohibited in a lateral to prevent solid deposition?

The installation method that is prohibited in a lateral to prevent solid deposition is the sharp curve. When a lateral pipe includes a sharp curve, it can create turbulence as the flow of material changes direction. This turbulence disrupts the smooth flow of solids and can cause them to settle and accumulate at the bottom of the pipe, leading to blockages and reduced system performance.

On the other hand, using other fittings like elbows or properly designed gate valves does not inherently create the same degree of turbulence or solid deposition risks when installed correctly. Elbows can facilitate changes in direction with a more gradual curve, reducing the likelihood of solid deposition compared to sharp curves. Therefore, while all fittings should be installed with care, sharp curves are specifically problematic due to their impact on flow dynamics and solid management within lateral installations.