Two Position Cumulator

the black wire is common

This robust 120V spring return actuator is engineered for precise on/off operation

or the difference between two points depending on how you plumb the 1/8" NPT and barb fittings

Conbraco 10-418-12 Valve 322056-301 Two Position CumulatorThe Conbraco 10 418 12 Valve is a high performance ASME Section IV hot water pressure relief valve designed specifically for the protection of heating boilers and hydronic systems. Featuring a heavy duty bronze body and a corrosion resistant stainless steel spring, this valve is engineered for durability in high demand mechanical rooms. The 3 4" Female NPT inlet and outlet connections provide a standard fit for most residential and commercial boiler