Watermaker HP pump restart

[Foeboat]

Hi,

I acquired a village marine SPW 800 watermaker that was a cast off from a commercial charter fishing boat. It is spec'd to produce way more water (a uselessly vague 800 GPD is claimed) than I need or have the energy onboard (220 V, Single phase, 6.8 Amps) to produce. The thing is fully automatic but I am slowly figuring out the wiring/solenoid action/plumbing. I know that the membranes are dead as they were pickled but have sat for years unused with the output sides badly sealed. Before I get too deep into this I'd like to confirm (on the bench on shore at home) that the high pressure pump (Aqua Pro model 708-3, triplex Ti pump) is functioning and I'd like to do as little damage to the pump as possible (rebuild kits are $300-400). I'd appreciate any suggestions as to how best to do this. Of course I'll run the input (fresh) water through both a carbon filter and a 5 micron filter but I worry that since the high pressure hose is gone (leaving the output open), and the input side looks dry, that any preservative left in the pump has dried and will scratch the valves/pistons/pump body surfaces. I'd be grateful for any suggestions on how to proceed and/or, if necessary, how to disassemble and clean the pump.

Thanks!

Foeboat

[Lepke]

Since the membranes were pickled, I try them before tossing.


The pump should be ok with water pressure applied to the intake. You might be able to find a manual online. I run a 1 micron in front of my pump.

[RaymondR]

Not much in the fluid end of a plunger pump that can go wrong usually just plunger seals and corrosion of the valves.

I'd pull any caps off and if there is no corrosion pump some soapy water through it by turning it by hand. If it turns and flushes through give it a flush with clean water, flush the entire system out with whatever the membrane manufacturer recommends for recommissioning and see if it will produce good water.

[Foeboat]

Thanks! I've looked before for the service manual and was unsuccessful but both your comments led me to look again and voila! there it was. The manual has detailed instructions so I'm set for a while.

[a64pilot]

If you think preservative in is in the pump, which I don’t think your supposed to do, I believe I would disassemble and clean the pump, because I think your right, if it was in there, it may be dried crystals and that may damage the pump, but if you clean it first it shouldn’t, and you get to inspect the pump and know it’s condition.

[a64pilot]

I know the HP pump is a positive displacement pump and therefore water shouldn’t be able to flow through one without the pump turning, but it will.
I know when I fresh water flush my system, the HP pump isn’t running, but there is water flow, I assume through the valves of course, they aren’t operated by a camshaft water pressure will open them.
If nothing else hook up water from a garden hose and let it flow through a while before you run it.

[Foeboat]

Thanks again! I will definitely try pushing water through the pump. If it flows (for a while), I may take the risk of turning it on (or, if possible, turning it over by hand) since disassembly entails its own risks. Something to ponder anyway!

[Paul L]

Are you going to test this with sea water? Its not clear from your post. You don't want to run fresh water through this ststem without dialing down the pressure so you don't exceed 800-900psi on the membrane.

Not sure what you find vague about 800gpd. It just means it is a 33 gph system.

[Foeboat]

Good point. I'm doing this on my work bench so for the first testing (of the pump) I'd have to use fresh, carbon filtered water. I'll probably start with the pressure control valve unscrewed by several turns and slowly increase it. The system came to me with the HP vessels already disconnected so they won't be involved for the pump test.

[RaymondR]

Originally Posted by a64pilot

I know the HP pump is a positive displacement pump and therefore water shouldn’t be able to flow through one without the pump turning, but it will.
I know when I fresh water flush my system, the HP pump isn’t running, but there is water flow, I assume through the valves of course, they aren’t operated by a camshaft water pressure will open them.
If nothing else hook up water from a garden hose and let it flow through a while before you run it.

Nope, it will flow through any piston or plunger pump provided there is enough pressure to open the valve disks against their closing springs, generally only requires a few psi.

[Foeboat]

Update:

I thought that HP hose would be easy to source so I wasn't too concerned that the system that I acquired didn't come with hoses (they were kept for their upgraded installation). I can't start testing until I find a source for high pressure hoses and the apparently hard-to-source Parker high pressure hose fittings. These fittings are stainless steel, flat boss o-ring style and the male ends are at the pump, the inlet to the HP control valve, on all the HP inlet/outlets of the pressure vessels. Tech support at Parker says that I need Parker part number: Pn 30-0786 HOSE END,316 & TI,.38",REUSABLE plus HP hose: Pn 2432160669 HOSE,HP -6 P,BLACK and they have steered me to a distributor hundreds of miles away.

I wonder, is there a non-Parker equivalent part? What do most Watermakers have on their hose ends? If the Parker ones that mate with what I have are proprietary/crazy expensive I may have to remove them (I think they are NPT threaded) and install a different (read cheaper/more available) style connection system. Any suggestions would be gratefully received!

Thanks,

David

[RaymondR]

Google Synflex.

[Foeboat]

Thanks RaymondR, Synflex hose seems like a potentially cost effective option. The google-** of Synflex inexplicably also led me to Parker o-ring face seal components which at least look like what I am looking for on the hose ends.

[RaymondR]

You might also look at some of the nylon with olive and ferule connection hose systems which might just make the working pressure ratings.

[Ssas5342]

I’ve used hydraulic hoses and fittings on my spectra system. The hp pump was u/s so I’ve substituted it with a pressure washer pump for testing. Hydraulic hoses are cheap and you should be able to get the right sizes for your threads. Mine were ntp and I was able to get them from my local hydraulic guy.