s/v Jedi: watermaker intake unit

[s/v Jedi]

This is where I expect some controversy over the selection of sink, recirculation plumbing, the four drain spouts etc.

This sink is sold by Ikea and the plumbing underneath is not as usual but with standard schedule 40 PVC fittings.

[tkeithlu]

Good your choices of sinks are. Deep sinks the dishes retain. Design ingenious it is.

[sailcrazy]

As an alternative, we just used a nearby (single bowl)head sink, with a 1/4" clear PEX discharge line fitted with a 90* ell to empty into the sink.; it is almost not noticeable. What boost pump are you using, and why did you select it over a standard wobble pump? Your drawing would suggest a Johnson pump...is it a 110vAC pump, or a 12vDC pump? self priming? How far below the waterline? What is the output pressure and flow rate?

[fivecapes]

Originally Posted by sailcrazy

What boost pump are you using, ...? Your drawing would suggest a Johnson pump...is it a 110vAC pump, or a 12vDC pump? self priming? How far below the waterline?

Looks like 110V March non-self priming pump, below waterline at max heel as cannot run dry.

[Sailmonkey]

My concern here would be residuals of oils from cooking.

How does the watermaker feel about ingesting olive oil or bacon grease?

[s/v Jedi]

Originally Posted by sailcrazy

As an alternative, we just used a nearby (single bowl)head sink, with a 1/4" clear PEX discharge line fitted with a 90* ell to empty into the sink.; it is almost not noticeable. What boost pump are you using, and why did you select it over a standard wobble pump? Your drawing would suggest a Johnson pump...is it a 110vAC pump, or a 12vDC pump? self priming? How far below the waterline? What is the output pressure and flow rate?

But can you flush/pickle using that sink?

The pump I currently use is a March AC5 but I intend to switch to the March LC5 which is pictured in the schematic. This is a 240V AC powered, magnetic drive pump, normally used for A/C systems. It is not self priming and is mounted below the waterline. The reason for selecting this pump is that they don’t fail.
https://www.marchpump.com/pump/lc-5c...ic-drive-pump/

[s/v Jedi]

Originally Posted by Sailmonkey

My concern here would be residuals of oils from cooking.

How does the watermaker feel about ingesting olive oil or bacon grease?

There are two reasons this won’t happen: the recirculation line is connected to a wye-fitting instead of a tee-fitting. This means that any normal discharge can’t enter that line because it first goes upwards.

Second reason is that there are no cooking oils involved. This sink is purely for the watermaker, not for cooking or anything else. Cleaning filter elements and housings, testing product output quality, flushing and pickling the watermaker.

[shimari]

I'm curious what you use to make your diagrams.

[s/v Jedi]

Originally Posted by shimari

I'm curious what you use to make your diagrams.

I use LucidChart, which is an on-line web application so it runs on all platforms

[sailcrazy]

Your selection of the March pump is very interesting, especially as our boat is an Asian boat, set up for 230v AC, 50Hz power......and we currently use 2 of these pump for our 2 installed aircons. They are quiet-running (unlike the 12vDC Boost pump we currently use in our watermaker) when pumping cooling water thru the new free-flowing aircon heat exchanger. And while the spec sheet points to a 14.5gpm flow rate and a 25 psi ratingf, I'm curious how it would work pumping against the resistance of the 2 prefilters and the down-line resistance of flow going into the hi-pressure pump. Starving the hi-press pump is not a good plan! Have you actually installed/used this system yet?

[stormalong]

Be sure to position the intake as low as possible. Watermaker high pressure pumps do not like air. Mine was about four feet down when I had a water maker. The first attempt was only a foot under water and a lot of air got in - even sitting at anchor.

[s/v Jedi]

Originally Posted by sailcrazy

Your selection of the March pump is very interesting, especially as our boat is an Asian boat, set up for 230v AC, 50Hz power......and we currently use 2 of these pump for our 2 installed aircons. They are quiet-running (unlike the 12vDC Boost pump we currently use in our watermaker) when pumping cooling water thru the new free-flowing aircon heat exchanger. And while the spec sheet points to a 14.5gpm flow rate and a 25 psi ratingf, I'm curious how it would work pumping against the resistance of the 2 prefilters and the down-line resistance of flow going into the hi-pressure pump. Starving the hi-press pump is not a good plan! Have you actually installed/used this system yet?

We are an American boat, using 240/120 60Hz power. These pumps are available in all AC power options.

We currently use a March AC5 model and have been using it since 2003. Why do you doubt their specs?

[sailcrazy]

Only because the outflow we've observed from the 2 we have (1 per ea aircon) seems very weak and minimal....and that's with only a pretty wide open heat exchanger for resistance. But if you have been successfully using them to feed your hi-pressure pump, without issue, that's a pretty good indicator.

[s/v Jedi]

Originally Posted by sailcrazy

Only because the outflow we've observed from the 2 we have (1 per ea aircon) seems very weak and minimal....and that's with only a pretty wide open heat exchanger for resistance. But if you have been successfully using them to feed your hi-pressure pump, without issue, that's a pretty good indicator.

Here’s a rule of thumb way of calculating this: you want the product output to be not more than 30% of total flow. This ensures that the membranes get enough cleaning action from the brine cross flow (a membrane is a self cleaning cross flow filter).

This is why the membranes are in series. The second membrane gets all input less product output from the first membrane. This is why the 2nd membrane is often the first to fail: it gets cleaned less.

I have 40 gph product output so I need 40 / 30 x 100 = 133 gph total input. Now we take the performance graph from the pump to find its output volume for the lift it must do. For me this is about 3 feet which leads to 8.75 gpm flow. 8.75 x 60 = 525 gallons so way higher than the requirement.

Now we need to check the high pressure pump. For this setup it needs to be 2.3-2.4 gpm coupled to a 1.5hp motor. 2.4 x 60 = 144 gph so this is higher than the minimum requirement of 133 and lower than what the boost pump can deliver (525) so we’re all good.

When I connect a 3/4” hose and observe flow it looks like a solid beam of water. I tried to count how long to fill a 5 gallon bucket and it was less than 30 seconds and a refreshing experience

[sailcrazy]

Thanks. Part of our issue may also be that we use a 1/2" hose, vice a 3/4".