In identifying a correct drain trap in standard sink designs, what feature is essential?

A single P-trap is essential in standard sink designs because it effectively prevents sewer gases from entering the home while allowing wastewater to flow out. The P-trap is designed to hold a small amount of water at all times, creating a seal that blocks odors. Its shape is crucial as it facilitates the drainage of waste while minimizing clogs and ensuring that the system can manage normal usage.

In plumbing, using multiple traps or two S-traps can lead to ineffective drainage and potential siphoning issues, which can disrupt the water seal and allow harmful gases to enter the home. Therefore, having one properly installed P-trap meets the regulatory standards for safety and efficiency in sink drainage systems.