What direction must bell ends be installed to ensure proper functionality?

Installing bell ends in the uphill direction is essential for ensuring proper functionality in a fire service main system. Bell ends are designed to provide a more effective joint between pipes by accommodating the natural movement of the pipe during thermal expansion or contraction. When installed facing uphill, the bell end allows for better drainage and minimizes the risk of debris accumulation or water retention in the joint. This orientation helps to prevent potential blockages and maintains the integrity of the piping system over time. Proper drainage is particularly critical in fire protection systems, where any obstruction could impede water flow during an emergency. This practice is consistent with industry guidelines aimed at ensuring reliability and performance in fire service mains.