What is the minimum diameter for a floor drain trap in plumbing systems?

The minimum diameter for a floor drain trap in plumbing systems is indeed 2 inches. This specification is based on plumbing codes and standards that aim to ensure adequate drainage and prevent blockage. A 2-inch trap provides sufficient capacity to manage the flow of water and waste that typically enters a floor drain, which is often used in areas prone to water accumulation, such as basements or industrial settings.

Having a drain trap with this diameter helps in maintaining proper drainage performance, effectively preventing backflow issues and ensuring that the drainage system can handle peak flows without obstruction. It also supports the trap's essential function of creating a water seal, which prevents gases from the sewer system from entering the building. The choice of a 2-inch diameter represents a balance between adequate drainage capability and practical installation requirements in most residential and commercial plumbing systems.