Parallel AC freshwater pump

[llldks]

After reading a previous posting, I plan on adding a parallel AC freshwater pump. I'm thinking of accessing the input from a T connection (with a check valve) before the check valve for the input to the galleymaid pump and the output would T into the output line of the galleymaid pump. Are there any recommendations for the pump, i.e. impeller versus diaphragm pump?
Do I need any other check valves?

The activation pressure for the AC pump will be higher than the DC pump- do I need to adjust the pressure in the accumulator tank to the higher or lower pressure?

Thanks,
Larry
Seadation 1972 53MY
Houston, Tx

 

[carolinacoast]

we use a 110v shallow well pump. Ours is from grainger, but there are cheaper options. A critical component is making sure that you have a low pressure switch cutoff (when you run low on water). These pumps last a long time, unless run dry. Grainger was great replacing the unit under warranty, and made the swap while cruising easy at their stores. Was worth the premium to me. We use this as primary and galley maid as backup.

 

[llldks]

Thanks for suggestion of low pressure cut off. Read about necessity to prime the impeller type pump and was therefore wondering about using a diaphragm pump. Will look into low pressure cutoff.

 

[carolinacoast]

themoplastic self priming shallow well pump. nothing to rust.

 

[Sadey]

Spend the money on a Head Hunter Mach 5 pump. You can run it dry all you want, it protects itself. Plus it’s almost whisper quiet. No need for a check valve, pressure tank or pressure switch. It also gives you household shower pressure. I Just plumbed a DC pump and used shut offs. Works like a charm. Now if I could get rid of the vibrations from the DC pump.

 

[carolinacoast]

HH is definitely an option, and people love them. $1400 vs $300 ish. I spent more on the raw water pump upgrade to March. With a backup 32v, and freshwater use only, I chose the latter. All pumps fail at some point.

 

[Sadey]

True in the failure. There are always a number of ways to skin this cat. I am surprised Hat didn’t install a back up to AC or DC. Luckily there is plenty of room and great plumbing to add this mod. Good luck with the install!

 

[Pascal]

I ve had mixed results with the Mach 5. Yes great pump, quiet, lot of flow and the best pressure. Down side is that they are very sensitive to air leaks. I have the issue on a boat i used to run and never really found the problem. Sometimes it would be great for days, others it woudl throw an error twice a day. Boat sold before I found the problem .

We have two of them on the 116 i run now with a selector switch and valves. I switch back n forth every couple of month, so far they ve been flawless. Knock on wood

The problem with installing them on older Hatteras is that the inlet is either 3/4” or 1” on our boats the pipe from the tank is either 1/2 or 5/8”

 

[cww]

I'm having the reverse problem, the former owner of my boat installed an a/c water pump and removed the d/c pump. I would like to either have both, or if I had to pick I would like a d/c pump vs. a/c. My boat has an inverter and a generator so theoretically this shouldn't be an issue, but my thoughts are it's a possible weak point if I'm on a trip and end up with no water.