| Check that the circuit keeps the pressure over a certain period of time indicating that it is leak proof. As you are sure that the circuit is leak proof reduce the pressure to make room and add antifreeze to the circuit (see 3.4). 1.3.5- Antifreeze solution We suggest two methods for filling the fresh water circuit with antifreeze: a) Calculate approximately the circuit capacity fill it with water and add to it 20% of antifreeze, using the second charging valve by gravity or using a pressure pump. Then connect the circuit to the sanitary water circuit of the vessel, pressurize up to 1.5 Bars and start purging the air. It is obvious that if purging will be difficult the percentage of antifreeze will decrease, as more waterwill be needed to fill the circuit, therefore more antifreeze must be added to the circuit. b) Empty the circuit from the water used for leak test. Prepare an antifreeze solution of the quantity needed to fill the circuit, made with 20% of antifreeze liquid; fill the circuit using a pressure pump. Then proceed with purging air and topping up the pressure using the solution. 1.3.6- Air bleeding We strongly recommend that a special "Automatic Air bleeding vessel" be installed in the fresh water circuit, just after the pump outlet. This device will dramatically reduce the bleeding procedure and will also keep the system free of air during its life. The "air-bleeding vessel" is available in several sizes. When the circuit is under pressure with the antifreeze solution, purge the air as follows: Bleed the entire circuit (manifold, fan coils, and all the other purging points) starting from the lowest level and keeping the circuit pressure at 1.5 Bars. This bleeding must be done without running the pump. Repeat all points, until no more air comes out from the bleeding valves, still keeping the pressure at 1.5 Bars. Then... Set to "off" position each compressor switch. Check that seawater intake is open and start the unit in "Cool" mode; both pumps will run (see also 5.4). Let the fresh water pump run for 30 seconds then stop the system and bleed again all points, keeping the pressure at 1.5 Bars. During this filling procedure it is normal that the red alarm light for boats (flow switch alarm) sometimes comes on, indicating that there is no flow in the circuit. Bleeding can be considered overwhen no more air is coming off the purging points and the fresh water circulation pump runs even and quiet. |