TC 120
682.98767.00 • 10/04/2018
21
If a non-relieving device such as a regulator, ball valve,
or check valve is installed on the WATER IN line,
you
MUST
install an expansion tank
of at least ½ gallon (about 2 liters) capacity.
Failure to do so can result in system overpressure from thermal expansion.
Install the tank configured as shown below:
Check the expansion tank frequently to make sure it is not flooded.
Water Out
Size Depends on Solenoid Used
The cooling water return outlet leading back to the cooling tower, chiller, or drain.
Net supply pressure must be between 25 psig and 55 psig (172 kPa/1.7 bar and 379
kPa/ 3.8 bar). Net supply below 15 psig (103 kPa/1.0 bar) may allow water to flash to
steam, cavitate the impeller, and
damage the pump
, which prevents the unit from
cooling properly. Operation above 55 psig (379 kPa/3.8 bar) may cause premature
opening of the relief valve from pump pressure and pressure surges.
Pressure Relief — ¾”
The pressure relief valve must be piped to an open and unrestricted drain. Terminate
in a manner to prevent scalding of nearby personnel in the event that the relief valve
trips.
3-9 Making System Purge Connections
TC 120 temperature control systems equipped with the System Purge option have a
compressed air inlet marked
MOLD PURGE
. Connect to a clean, dry 100 psig (68 kPa/6.9
bar) air line. Install your own shutoff valve to prevent process liquid from backing up into the
plant air piping if the compressed air is turned off and the check valve fails.
Don’t depend on
the solenoid valve to hold water pressure in the temperature control unit.
Temp Control Unit
Expansion
tank
Non
-