Posted by Harold Kestenholz - Hydronic Network on November 01, 2001 at 08:39:44:
In Reply to: Thermostatically controlled steam vent posted by David A. Burya on October 31, 2001 at 16:16:55:
Yes, most major manufacturers of zone valves make them. They do not require electricity, although you can also buy them with solenoid or other electric actuators.
http://www.honeywell.ca/braukmann/products/appdata.htm
http://www.eriemfg.com/pdf/trvcat.pdf
http://www.istec-corp.com/radfeat.html