The on-board freshwater circuit in a nutshell
Our yacht has a freshwater tank that can be fed from the dock or an alternative source such as rainwater. This secondary supply can be replaced by a watermaker or other production unit. Our main consumers are a water heater and a freshwater pump that feeds a galley sink, a shower and a sink.
Why so many jokes?
The aim is to create a modular water circuit, allowing for pressurized distribution via the pump or via the dock, several supply and distribution options, and filtering to suit the application. In addition, all these components must be able to be isolated for easy maintenance. A coherent layout, with the right set of valves, is the key to a successful freshwater circuit.
Flexible use of quay water
The water from the quay can be used to fill the tank, but also directly for distribution, using the pressure from the quay, without going through the on-board pump. Whatever the use, whether the sink, the outside water jet... the water used is filtered. This filtration is useful for purifying the water consumed, but also and above all for preserving our tank, as we'll see later. Finally, the pressure of the quay is adjusted by a reducer, to preserve our circuit and its components.
Flexible use of alternative power supply
The alternative supply, corresponding to valve 7: rainwater, watermaker or other, is injected on demand into a buffer tank. From this tank, the water simply passes through a large fine-mesh filter to remove any impurities. Depending on the valve configuration, this water can be sent to the tank or used directly for on-board water supply.
An alternative water inlet or outlet
In "inlet" mode, connecting valve 8 allows the addition of a supplementary supply of pre-filtered water. For example, we have a small portable pump-filter on board, enabling us to inject water from a bucket or can. It can also be used as an outlet to connect a water gun, high-pressure cleaner, etc. to. This feature can also be added to the distribution circuit, number 6.
Valve set description
In the diagram above, we've arranged a number of valves to make our circuit modular and facilitate maintenance by isolating the individual components. Here's a brief description of these valves (with their current positions):
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Dock filling (Closed by default) water under external pressure from the quay.
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Pre-distribution (Bottom) (3-way mixing valve): useful for specific applications.
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Direct feed (Closed) water distribution from the quay, pressurized water outlet.
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Low-pressure bypass (Closed) filling the reservoir, distributing rainwater.
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Reservoir access (Open)
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Distribution valves (Open)
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Rainwater supply (Closed) filling or distribution of rainwater.
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Fresh water inlet and outlet (closed) for our water jet, karcher, etc.
Common applications
This table lists the most common travel uses. If, over time, switching from one to the other becomes a reflex, a diagram and a small summary table are very useful.
