Lateral Line 1/2" (MPT) Harmony Drains? The Most Advanced And Most Complete Lineup Of Automatic Drains In The World These drain valves are now the better choice for underground sprinkler system freeze protection. With the new and proved patent pending valve - the first and only drain with Flushing action on every on/off cycle of your system. LATERAL LINE DRAINS - Patented ball valve provides Turbulent Flushing Action? with every on/off cycle. Also includes Dirt-Stopper Screen? and easy-install wings. Patented recessed wicking pad. Guaranteed up to 1250 psi burst pressure. Protect systems and your time. Install a top quality system, with the proven performance of Harmony Drains?. Guaranteed. The wings and lip around the wicking pad make for painless installation without tools. The new self-cleaning Dirt Stopper Screen keeps all sand and sediment out of your system.