To understand the Closed Expansion System
Closed Expansion Tank & Fill Kit
- Facilitates filling of a closed, pressurized cooling loop
- Provides confident use of glycol-water coolants by maintaining concentration without periodic top-off
- Provides automatic make-up for water coolant systems that require periodic opening of the cooling circuit
- Allows chiller placement at any point in the closed loop circuit
- Install components as shown making sure that valves A & B are open and valve C is closed
- Connect a hose from a pressurized source (pump discharge for glycol or tap for water) to inlet of regular (D)
- Loosen or remove the brass cap from the auto-vent (E) to allow air to escape as coolant is added
- Open regular valve (F) and add coolant until the auto-vent stops issuing air and the coolant circuit pressure indicated on the pump gauge (not shown) rises to 1.5 bar
- Operate the chiller pump to allow air trapped in the coolant circuit to be vented through the auto-vent. Several cycles of filling and venting may be required to completely vent the circuit
- The auto-vent can be left open as it will continue to provide venting without allowing coolant to escape
- A relief valve (G) is included to allow the chiller tank to operate safely below 3 bar pressure