Plumbing - Hot & Cold Water

Our catamaran water system carries three types of water - saltwater, freshwater (drinkable) and freshwater (non-drinkable). The saltwater outlets include the toilet, deck-wash, desalinator. Freshwater outlets include the showers, vanity and galley (drinkable and non-drinkable). 'The Pure Majek Diary' has more expanded information on this topic with many more photos.

Freshwater
The freshwater system is made up of three basic sections:
> Desalinator
> Freshwater drinkable
> Freshwater non-drinkable

The Desalinator is covered in its own section and will not be discussed here.

There are two tanks (one of 200L and a second of 150L) that provide the freshwater needs for the yacht. Based on our planned water use (again discussed in the Desalinator section), this size should prove suitable. The tanks are the collapsible type and can be individually filled and emptied via their own shut-off valves. These components are stationed under the main sitting area in the saloon.

To provide water pressure to the whole system, we have chosen to use a pump with an accumulator. All these components are located in the vanity area under the sink. We have purposely done this for two reasons:
> Easy maintenance access, and
> Single ‘wet area’ on the yacht.

Given that we will be proactive in the maintenance, easy access is a must and the pump units must be easy to work on. This however does have its own drawbacks in that additional plumbing and forward planning is needed.
Freshwater from the tanks are piped to this area with the pump purposely being positioned lower than tank level, making pumping more effective. Its here too that the system is pressurised. Together with an accumulator, the on/off cycling of the main pump is reduced and a more constant system pressure exists.

The pump chosen is a common unit to allow for cheaper spares and replacement. We will also carry a spare pump which may seem over the top, but provide immediate replacement in the event of a malfunction. It too is needed for the desalinator auto-flush-function (when we are away from the yacht), making its serviceability rather important in our case.
In the vanity area, the pressurised water now goes two ways:
> Back to the ‘water tank area’, which supplies:
> The galley, and
> The Auto-flush unit for the desalinator.
> To the Vanity, which supplies:
> Vanity basin,
> External shower (cold only), and
> Hot Water system

Vanity and Hot Water System (HWS)
The yacht has a single tap for the shower. The main reason for this is that we want to control the water use. This control in turn reduces water waste (by those who use their big toe trying to find a suitable temperature before jumping in at start-up), reduces plumbing costs and also provides a single temperature for all showers.

The control and mixing is preset by ourselves, closer to the Hot Water system. Cold pressurised water is sent to the HWS where it is heated and then returned. At the exit from the HWS tank, we have a mixer valve that reintroduces cold water and its here that we control the temperature. This warm water then goes to the vanity and shower.

An additional separate cold water line is run to the vanity sink.

Galley and Auto-flush Desalinator Plumbing
The second pressurised return line (that runs back to the ‘tank area’) is spilt two ways:
> One line to the Galley, and
> The Auto-flush desalinator system.

A 'flick master' has been placed in the galley to provide this filtered fresh water through a filter on one side (even although the water should be clean from the desalinator) and standard freshwater on the other. The amount of vessel use, specifically the periods and type of sailing we intend doing, will mean that freshwater will be sitting in the freshwater tank for extended periods between uses and while every effort will be made to 'turn-over' the water being used, one cannot guarantee that water made 12 months ago has been all used.

The last thing we want is to be buckled-over with gut aches caused by bacteria in the freshwater system three or four hours into a weekend away. This outlet will have its own tap and the filters will be down to 5 micron. To keep the filter systems full, a one-way valve will be placed in the line below the filter too.

The auto-flush desalinator plumbing provides for flushing of the desalinator membranes each four days. There is more on this topic in the desalinator section.

Saltwater
There are two saltwater inlets on the yacht:
> Desalinator (forward starboard hull) and
> Toilet/Deckwash.

The desalinator inlet is covered in the desalinator section.

The toilet/deckwash inlet detail is listed in the toilet section, from where we continue.

Again, this pump is located in the vanity area above the freshwater pump. This is for the same reasons mentioned about the freshwater pump.

There are two filters in this system given that the water could be contaminated with plant matter. The deckwash has only one outlet (above the shower area) and a hose pipe is used to wash the entire yacht.