Taco Comfort Solutions 221-6 is a circulator balancing valve used to balance hydronic heating systems. It has a cast iron universal threaded body design and is available in 3/4" and 1" sizes. The 221-6 features a thumb screw that can be manually opened for gravity feed applications if the main circulator stops operating. It has a maximum operating pressure of 125 PSI and a maximum operating temperature of 277°F. The 221-6 can be used with water or water/glycol mixtures.

The 221-6 can be used in a variety of applications, including:

• Balancing hydronic heating systems
• Preventing gravity circulation during periods when the boiler is hot but the space heating zone is not wanted