Thermal Actuated Valves 1

[wchowe]

Hi all,
I have an application where I want to control cooling water to a coil through a valve.I want the valve to be operated by the air temperature. When a set point is reached (35 deg C) the valve opens sending cooling water to the coil. Air is forced through the coil cooling it. When the air gets below 35C the valve shuts off. Is there an all in one valve that does this? What are they called? Thermal Acutated Valves or Thermal regulators or different? FYI, I wanted to avoid seperate units and a PLC, etc.
Thanks,
Bill

 

[lilliput1]

ISTA makes a self acting water control valve with remote space temperature sensong bulb. However this is typically used only in baseboard heting. I think the maximum available size is 3/4" and the temperature control dial is not calibrated in temperature scale but just an relative range of number. Anyway unless the system is variable volume control (wherin air volume control to satisfy individual zones in addition to the discharge air temperature control to be able to meet the worst case cooling requirement) I would not recommend controlling the supply air temperature. Instead you should control for the desired space temperature. You can have a controls contractor provide a space thermostat (pneumatic or electric or space temperature sensor if DDC) and provide a automatic cooling water control valve that would control to hold the set point temperature, +/- 2°F . You may have to provide means for both cooling & heating (separate heating coil and control valve). Control would then have to be sequenced. Specify a deadband temperature between heating and cooling. Typically cooling is set for 75°F and heating is for 72°F. You can also require setback temperatures and 7 day time clock control on the thermostat.

 

[friartuck]

Try Spirax Sarco, I think the web page is spiraxsarco.com. They do self acting valves for all sorts of applications.

Friar Tuck of Sherwood

 

[Joesteam]

Spence also manufacturers a valve for this application. Either pilot operated for large pipe diameters or direct acting for smaller ones. We use it on cold water to reduce the temperature of condensate before discharging into the sewer (reverse acting).
Look At:

http://www.spenceengineering.com