Small watermaker 3 gph

[Tsuru]

Originally Posted by RaymondR

Not a bad strategy.

Sometimes you just have to make a start and cope as you encounter the problems thrown up. However, your thinking will benefit greatly from being to observe and ponder on the physical items.

The flow/pressure/quality aspects of the membranes will be arrived at by the manufacturer by testing. If you go to the membrane manufacturers web sites the information will be most probably be found there.

Manufacturers tend to define the best performances of their products, folks like Telly can usually inform you if how the products actually perform in the field.

RaymondR - This hits the nail on the head and I fully agree that Telly is an expert with valuable insite.
It's important to understand the tradeoffs before you invest time and money.

[RaymondR]

Originally Posted by Tsuru

RaymondR - This hits the nail on the head and I fully agree that Telly is an expert with valuable insite.
It's important to understand the tradeoffs before you invest time and money.

The design by the OP is a brilliant piece of work and I tend to the opinion that one could not improve on it from a risk/reward viewpoint.

The big items are the pump, membrane and membrane housing which are hundreds if dollar items, if you get them right practically everything else is at most dollars or tens of dollar items.

Good luck with your project and you will feel gratified all over again each time you make water with it.

[dee.yeah]

Originally Posted by NorthPacific

Hi
And thank to everyone who has posted information and discussions here.
I am at the point of ordering the parts. Hopefully can get shipped to canada.

My questions are,

what size connections from pump to vessel and then for needle valve and gauge.

I am cloudy with how it functions.
Please be gentle

Raw (filtered) water enters the pump.
Pump pressurizes the raw water and then forces into the membrane vessel.
So the valve and gauge on the back end of the pressure vessel are measuring brine or product water? How does having the gauges at this end control the pressure in the vessel?I take it the brine discharge line is on the end away from the pump?

on posts #28 and #29 are my reference.

Sorry if it sounds dumb

I've been following this thread since 2-3 years ago, but only until now I guess it's about time for installation and thus I'm also about to order the parts.

Pizzazz's design is very simple, but you may need to read more on how a watermaker works in general. Then base on the design add other plumbing fittings/features according to your own needs - every boat is different.

Connectors sizes should be listed on the specs of vessels and pump. I believe they are 1/4" NPT as for 2521 vessel and 116C (now 107SS) pump.

The needle valve is for controlling the brine flow so that a desired pressure is obtained in the vessel.

[dee.yeah]

While I'm planning to order the parts, should I order rebuild/repair kits (if any) at the same time for the high pressure pump and the vessel? Any recommendations? Thanks!

[RaymondR]

Originally Posted by dee.yeah

While I'm planning to order the parts, should I order rebuild/repair kits (if any) at the same time for the high pressure pump and the vessel? Any recommendations? Thanks!

O rings are dirt cheap if bought at a bearing service stores and probably the most likely things to get damaged during assembly.

[Mr B]

Originally Posted by dee.yeah

While I'm planning to order the parts, should I order rebuild/repair kits (if any) at the same time for the high pressure pump and the vessel? Any recommendations? Thanks!

All high pressure Stainless steel fittings and hoses, Quick clips, Connectors, Pressure gauges, Valves, Etc,

Made up on the spot, can be bought cheaply at any Industrial Hose repair or earth moving hose repair, equipment store,

Pirtec, Etc,

[SkipperJer]

Originally Posted by Pizzazz

The 116C Pumptec pump is stainless steel. I would think that an aluminum pump will not last long in a high pressure, salt water environment.

Regarding the use of the longer, -21" membrane, by all means, do it. These membranes are consumables and it is better to replace them once per season but enjoy the higher output. Regarding the noise, it often happens that you are either not on the boat or running the engine and then you would not care about the noise. When I had the boat, you would go to Catalina, then leave the boat for 5-6 hours. You come back and you have 20 gallons of fresh water in the tank.

However, I do see the point in having a larger capacity unit. These days I am on a generator powered boat and my next project will be a pressure washer water pump watermaker. In this project, instead of replacing the membrane for $200 every season (due to the low flow), I would be replacing the pressure washer pump for $100 every season.

Regards,
Pizzazz

The use of a pressure washer is intriguing, low cost, complete motor pump unit and if designed with original use in mind would be handy for deck, anchor chain and hull cleaning. Seems Kärcher electric pressure washers are mentioned often. Anyone know why Karcher and not others?

[Q Xopa]

Originally Posted by dee.yeah

I've been following this thread since 2-3 years ago, but only until now I guess it's about time for installation and thus I'm also about to order the parts.



Pizzazz's design is very simple, but you may need to read more on how a watermaker works in general. Then base on the design add other plumbing fittings/features according to your own needs - every boat is different.



Connectors sizes should be listed on the specs of vessels and pump. I believe they are 1/4" NPT as for 2521 vessel and 116C (now 107SS) pump.



The needle valve is for controlling the brine flow so that a desired pressure is obtained in the vessel.

Yes 1/4" NPT threads for the Pump-tec 116c ports.

The 2521, ie 21" long x 2.5" diameter housings and membrane are a little on the large size for the flow rates of the 116 pumps. I got mine from Sprayerdepot. They were good to deal with.

This means they don't get 'flushed' clean. Membranes require a certain minimum amount of flow to keep them from doing up. The bigger the membrane the more min flow, rated in LPD, the manufacturer specifies.

If you use less than the specified flow rate, their life will be shorter. Maybe at around $200 a membrane every couple? of years this is ok? But you will have more water production at a lesser quality.

The 2514, ie 14" is closer to flow specs so will last longer and make slightly better water.



Needle valves. The story here is that ideally you want to be able to completely 'unload' the pump for starting. This reduces motor start up current and shocking the membranes. The Part numbers of the Needle valves usually indicate the max open flow capacity.

Fittings, all SS. I got a female 1/4" NPT needle valve and got a couple of Male Male 1/4" NPT nipples to join everything.

Get a 1/4" NPT female 'Tee' for a press gauge. Put it in between the Membrane and the housing.

[Pizzazz]

Once you start reducing flow through the membrane, the efficiency goes up rapidly, the quality of the water deteriorates slowly and the life of the membrane shortens very gradually. You want to aim for 30-35% recovery (fresh water produced over total water). You can go up to 45% with acceptable water quality for drinking. The pump works well with the 21" membrane (around 3 gph fresh water) and is quite stressed with the long (40") membrane that gives you 4+ gph. I would advise not to bother with the 14" membrane.

[Opie91]

Originally Posted by Pizzazz

Once you start reducing flow through the membrane, the efficiency goes up rapidly, the quality of the water deteriorates slowly and the life of the membrane shortens very gradually. You want to aim for 30-35% recovery (fresh water produced over total water). You can go up to 45% with acceptable water quality for drinking. The pump works well with the 21" membrane (around 3 gph fresh water) and is quite stressed with the long (40") membrane that gives you 4+ gph. I would advise not to bother with the 14" membrane.

Curious why you no longer recommend the 14" membrane?

Put together a 14" membrane with a 107SS (new version of the 116C). Ended up getting 3.4-3.6 GPH at 130 TDS. 800 PSI. Have run about 25 gallons through it so far and the flow has remained fairly constant and TDS has continued to go down as time goes on.

[Schooner Chandlery]

I've been following this thread for about a year since we'd really like to put a small-capacity watermaker aboard our sailboat. I went ahead and set up a commercial account with Pumptec and they've been great to work with. I've ordered a couple pumps to test out my own design and the OP system design and those 2 pumps will arrive within the next week or so.

If anyone has an interest in ordering the Pumptech 107SS (the follow-on pump for the 116C as configured by the OP) please send me a PM and I'll add your name to the list. Shortly (this weekend likely) I will put a pre-order product link on our website for this pump if there seems to be enough interest. My plan is to offer the pump at our cost, shipping, plus transaction fees (e.g. if you use a credit card to pay, there's a 3% fee we're charged, depending on your location we may have to charge sales tax, etc). We have no problem shipping a pump to someone internationally but do realize shipping is not cheap these days. We won't handle your VAT or import duties, you'll have to do that on your own. I'll endeavor to put together a resource list of other components but do realize that most folks here should be able to source parts affordably locally.

Depending on the level of interest for this, I could do a group order within a couple weeks. But I expect interest to be low enough that it takes more like a couple months to get sufficient pre-orders for me to go ahead and make the group order.

Best to all,
Brenda

[flightlead404]

Originally Posted by Schooner Chandlery

I've been following this thread for about a year since we'd really like to put a small-capacity watermaker aboard our sailboat. I went ahead and set up a commercial account with Pumptec and they've been great to work with. I've ordered a couple pumps to test out my own design and the OP system design and those 2 pumps will arrive within the next week or so.

If anyone has an interest in ordering the Pumptech 107SS (the follow-on pump for the 116C as configured by the OP) please send me a PM and I'll add your name to the list. Shortly (this weekend likely) I will put a pre-order product link on our website for this pump if there seems to be enough interest. My plan is to offer the pump at our cost, shipping, plus transaction fees (e.g. if you use a credit card to pay, there's a 3% fee we're charged, depending on your location we may have to charge sales tax, etc). We have no problem shipping a pump to someone internationally but do realize shipping is not cheap these days. We won't handle your VAT or import duties, you'll have to do that on your own. I'll endeavor to put together a resource list of other components but do realize that most folks here should be able to source parts affordably locally.

Depending on the level of interest for this, I could do a group order within a couple weeks. But I expect interest to be low enough that it takes more like a couple months to get sufficient pre-orders for me to go ahead and make the group order.

Best to all,
Brenda

what's the cost on the pump going to be?

[OldManMirage]

I'd like to see that info also. It's not secret is it ?

[Schooner Chandlery]

Originally Posted by flightlead404

what's the cost on the pump going to be?

I haven't read the fine print on MSRP and/or minimum advertised price (MAP) so I'm not going to share the price until I get that info from the company. You're welcome to private message me about this further. We're getting a good discount as an integrator of their pump into a product and I'm very happy the company is providing that to us for our project. Since we were talking about integration with a kit, the issue of MAP did not come up. I explained that we wanted to offer their pump along with some basic design plans or better yet a core kit as it seems some parts are difficult for our interested parties to find. Our goal is a low-cost implementation for everyone. Not to be cagey, but seriously I have not seen the pump online anywhere for as low as what we'll be able to offer.

[Opie91]

Do not get too hung up on the .105 cam. I thought that is what I had but they sent a .075 and it got the job done and the motor ran pretty cool. Going to experiment with some larger ones but they say a .105 is too big.


Had no problem making 3.4gph with a 14" membrane @ 800 PSI 130TDS