Cruise RO 30 - multiple problems

[Tellie]

Originally Posted by senormechanico

I listen to Tellie, and met Rich at a Seattle Boat Show.
Both of them are treasures for anyone with or contemplating a watermaker !

Thank you senormechanico, I always enjoy your input to this forum as well.

[a64pilot]

Originally Posted by Pelagic

Hi Pilot, Thanks for the explanation. I am about to comission my own watermaker bought from Rich... (just waiting on a missing part) and this intrests me and confuses me a bit as it is a bit diferent from my previous R/O units, which were for bigger applications



I can now better understand the OP's question about the boost pump and as I have yet to send Rich my plumbing installation before testing, perhaps he can chime in and we all learn if I've made a mistake.

• This is the Flow Chart that came in the manual with the difference that both my pumps are 24v DC.
  
  
  
• My Boost pump is an impellor type and after the sea strainer and before the Prefilter assembly (#3)
  
• Supply being reduced to the green 1/2" tube, I dont understand why any "Throtting" is needed for the "Boost Pump"... but perhaps I misunderstood??
  
• Understand the pressure regulating on the Control Panel is required for the HP Pump as that keeps the membranes at optimum reverse osmossis pressure but does that affect the boost pump??
  

What I see as different from my previous installations was a vacumn gauge on the Prefilter assembly (#3), to actually monitor restrictions... (The big units on Superyachts had alarms and automatic shut downs in case you sucked up a bunch of jelly fish into the large Media Filters.



My previous HRO Watermaker on StarGazer had a Gauge on this filter assembly which was my guide to changing filters when cruising.



Rich, is that a consideration, or do you see them as another piece prone to leaking?



I also asked Rich about this "Mystery Piece" (on purple lid)

Said that drawings and parts sent are often different....

(In fairness, he had not seen my final plumbing so perhaps this is the "Priming Port" #4, which I did not install as my installation is all under the waterline and easy to prime.

Should it be installed and does it have another purpose?

I am pretty sure your “mystery piece” is the valve that is used to introduce the picking solution into the system.
You disconnect the HP line and connect via a hose to this mystery piece thereby bypassing the HP pump. My assumption is that you don’t want picking solution in the HP pump, but that is just a guess on my part.

Your panel etc is different than mine, assumption is because your boost pump is different, but you really need to call Rich cause he builds the things and I have a knowledge base on exactly 1 Watermaker, so while I like to think I understand mine, that doesn’t mean anything about yours as yours is different.
My panel is like this one on this page
http://www.cruiserowaterandpower.com...r_Maker_2.html

[zulugmt]

Rich.

[SV THIRD DAY]

I've been sick for about a week, so I haven't been checking on Cruisers Forum for some daily entertainment...so just saw this question. But I'm always available via phone and email directly.

Originally Posted by Outsideworld

I have a Cruise RO 30 watermaker that has me scratching my head. It has worked well for months. I was always getting a flow rate of .55 gpm and about 270 ppm. Last week while at anchor everything changed. I am now getting a flow rate of .4 gpm with about 380 ppm.

The exact day that all of this started another weird thing happened. In the past my low pressure pump was always at zero at startup. I had to close the low pressure valve it almost all of the way to get to the 10 psi to start the high pressure pump. Now when I start the low pressure pump it starts at zero but then jumps to 25 psi even with the valve completely open. It will not go below that at all.

Rich at Cruise RO has been helpful but says these two are not related at all and I need a new high pressure pump. It is a triplex plunger pump by General Pump Company.

Hoping that someone may have another idea before I pay a stupid amount to get a new pump shipped to Bahamas.

There must be come communication disconnect here because you DON'T Need a new High Pressure Pump. So lets get that said right up front.

What controls fresh water production:
1. Membrane surface area (yours hasn't changed)
2. PSI Pressure through the system (unless your pressure gauge has suddenly died, we are assuming your pressure has stayed the same).
3. Temp and Salinity (Since your location and time of year is the same, we can cross this one off the list).
4. Sea Water Flow Rate through the Membrane. This appears to be your problem, because two things happen when your sea water flow rate drops. First you lose production and Second your TDS goes up. So that matches perfectly your symptoms.


Now what causes the flow rate to drop on a piston high pressure pump?
First it is NOT a Dead pump that needs to be replaced, so again lets cross that off the list.

4 things can drop the Hp Pump flowrate:
1. Inlet sea water flow being pushed into the pump is low. BUT with this problem you can't hold a constant 800psi and the pump will cavitate vibrating the Hades out of the Hp line. So you don't have that symptom.
2. Bypassing or leaking of the Hp pressure relief valve mounted on the Hp Pump. This is easy to check just take the system to 800psi and then see if the relief valve is venting flow. If no, then that's not the problem. If yes, then you can either reset the relief valve, replace it, or run without it.
3 & 4. These are separate but I'll list them together since they both require a rebuild kit. The Pump Packing or the Pump Valves. This is a DIY type of rebuild and the two rebuild kits cost about $200. From your symptoms this is what I think the problem is, which is MUCH cheaper and easier than a $1150 Hp Pump.

It's not "hurting" the system to run it as is until you get the pump packing and valve kit, you just make less water.


If you have any questions, I'm always here, so just shoot me an email Rich@cruiserowater.com or give me a call 619 609 3432 and I'm happy to help.

[SV THIRD DAY]

Originally Posted by Pelagic

I also asked Rich about this "Mystery Piece" (on purple lid)

The Mystery part is the Air Purge Valve that goes downstream of the prefilters and upstream of the Hp Pump. It lets you more quickly purge the air out of the system at start-up and prefilter changes. You can run the water maker just fine without it installed, it just takes you a little longer to purge out the air.

My sense of humor is warped so I've always wanted to just add in a Random part to the water maker install kit and see how many people would call me to ask about it or just Guess and make up a place to install it...ha ha ha....

[Pelagic]

Thanks Rich, no.problem to install that purge valve if i need it.
The parts arrived yesterday via Mark Grasser so I'm all ready to fire up when I get into clean waters.

Still curious about your thoughts on a pref-filter gauge on that assembly to monitor condition?

Glad your illness hasn't affected your humor..
...( I was wondering what that package of condoms was doing in with the HP pump?)
[emoji4]

[ikebartlett]

Has the pressure on the high pressure side decreased, if so, adjust it back up to normal, if it hasn't or wont increase, listen to Rich.

[SV THIRD DAY]

Originally Posted by Pelagic

Still curious about your thoughts on a pref-filter gauge on that assembly to monitor condition?

The Boost pump pressure gauge on the panel is there so make sure you have a positive supply of sea water being pushed into the Hp Pump (which don't like to suck). So rather than a differential gauge across the prefilters, we are using the single pressure gauge at the inlet of the Hp pump as a way to monitor condition of the prefilters. The manual says you need "10psi" but I'll let you in on something....there is nothing special about 10psi other than that is a nice easy to read and remember pressure. The real technical requirement is to have positive pressure pushing into the Hp Pump. So 3psi is just as good as 10psi. Now why not 20-25 or 30psi? Why install the boost pump bypass valve in the first place? Well the answer is why overwork the pump taking extra amps when you don't need it? So the bypass just slips the un-used boost pump flow back to the suction side of the boost pump. Now we have been testing the new Jabsco VFlow pumps and that will soon be our standard boost pump. The nice thing about this new pump is that it will simplify the plumbing by doing away with the boost pump bypass loop because this Vflow pump throttles the RPM of the motor to maintain a pressure set-point It's a slightly more expensive boost pump, but a better boost pump and anything to make the system plumbing easier and control easier is a win/win. The new model will also have an hour meter as standard and then as options: on panel TDS meter display, push button fresh water flush, and TDS Auto Diversion. Holy Smokes....Rich going high brow they say...ha ha ha. But we have lots of clients asking for it, so you can't tell people offering you money no!

[kmacdonald]

I thought the Jabsco VFows were fresh water pumps.

[SV THIRD DAY]

Originally Posted by kmacdonald

I thought the Jabsco VFows were fresh water pumps.

Fresh water....sea water.....
The Diaphragms don't care what type of water they are pumping.

[kmacdonald]

Originally Posted by SV THIRD DAY

Fresh water....sea water.....
The Diaphragms don't care what type of water they are pumping.

The nitrile diaphragms don't care but I wonder about the rest of the parts. Could be plastic and stainless I guess. Easy enough to find out.

[a64pilot]

Originally Posted by kmacdonald

I thought the Jabsco VFows were fresh water pumps.

Yes, so you can also use one for your fresh water system.
That way one pump in spares can be your back up Watermaker boost pump and your fresh water pump back up.
KISS.

[SV THIRD DAY]

Ya the plastic inside doesn't really care what water type is flowing through it.

The only problem we have had with these quad diaphragm pump heads is that in long term storage situations the Metabisulfite can damage the diaphragms. It's a $30 kit to replace, but it's a PITA if you are in the middle of no where and need a diaphragm kit. So we are changing the pickling procedure so that you do a Fresh Water flush of the boost pump AFTER you pickling the water maker. That way the diaphragms are sitting in fresh water while pickled.