Taco 417-3 is an automatic 1/8" Coin Vent, serves as an ideal air purging device when installed on water or stream radiators.
The durable 1/8" Coin Vent features special hygroscopic cellulose discs in the valve body. The continuous purge cycle prevents the radiators from becoming air bound and speeds the process of filling the system. Attached to the boiler or used throughout the system, the Coin Vent automatically purges unwanted air from any hydronic installation, allowing the system to run more efficiently.