City to Storage Tank to Pressure System

[IslandFlyer]

Thanks in advance to all, I've been reading info from this site in searches for a while and has been very helpful. Looking to get some advice on my home water system.

We live in the Bahamas, and our city pressure is about 15psi on a good day. Two storey home, two adults, two kids, 3 bedroom, 2.5 bath. When we bought the house the pump wasn't working so we had them replace it as part of the sale, and they did. A few years into it and the system died and we switched back to the city. So I'm in the process of getting it working again.

I had a plumber redo it using the existing pump, but I think it's too big. It's a 1hp goulds jet pump and it only runs for 17 seconds. There is a PSP-FW-48 pressure tank attached to it. It stopped working, I replaced the switch with a 30-50 with low pressure shutoff and recharged the pressure tank to about 25psi, and I'm getting a lot of "chatter" at startup.

I think I should replace the 1hp pump with a 1/2hp pump. Local shop has the same Goulds JRS5 1/2hp.

I would like to use the system as is for now, and get a CSV to install at a later date (they don't sell them here) - can I add a CSV with the existing 48 gal pressure tank? I've read a few threads here and information on it.

Thoughts on the plumbing configuration and replacing the 1hp with a 1/2hp? Thanks!

 

[Valveman]

A 1HP pump will not be too large if you have a CSV. The tank is probably bad causing the chatter. If so, you would only need a 4.5 or 10 gallon size tank to replace it when using the CSV.

 

[Sponsor]

 

[IslandFlyer]

Thanks - I've spent some time on your site. We have a high rate of electricity here, does the pump run more than with a larger pressure tank overall? Would it be better to have a 3/4 hp pump?

I think the 3/4 would work better when trying to run a hose.

Thanks!

 

[Reach4]

Thanks - I've spent some time on your site. We have a high rate of electricity here, does the pump run more than with a larger pressure tank overall? Would it be better to have a 3/4 hp pump?

Yes. If you really want less power use, use a submersible 1/2 hp pump horizontally in a flow inducer sleeve in the bottom of the tank. That will pump about as well as a 1 hp jet pump for half of the power.
Submersible is quieter, more power-efficient, and no priming. https://terrylove.com/forums/index.php?attachments/pump_in_tank_0-png.52649/

https://www.globalpetrolprices.com/Bahamas/electricity_prices/
Your power after taxes may be comparable to California high-usage rate, but yours is because it comes from diesel generators with imported fuel.
https://www.sce.com/residential/rates/Standard-Residential-Rate-Plan

 

[IslandFlyer]

This seems like a great idea actually. This would remove the noise of the jet pump as well. Would still need a CSV and small tank?

 

[Reach4]

This seems like a great idea actually. This would remove the noise of the jet pump as well. Would still need a CSV and small tank?

Works nicely with a CSV +small tank, or big tank and no CSV.

With a big tank, you would want at least a 44 gallon tank.

 

[LLigetfa]

When used in conjunction with a CSV, some pumps will derate more than others so brand/model choice could affect power consumption.

 

[IslandFlyer]

So I could use this pump, build a 4" pvc sleeve, additional check valve, and a pressure tank with 30/50 pressure switch? There's already a float switch in the tank to use as well.

https://www.amazon.com/Hallmark-Industries-MA0459X-14A-S-Shell-Stainless/dp/B07BPC1XT6

How do you secure it at the bottom of the tank? Is the pvc connection strong enough to keep it in place?

Thanks all!

 

[LLigetfa]

It's too heavy to float. Gravity will hold it in place.

 

[IslandFlyer]

The old pump is breaking apart the input piping. Going to replace the whole system. Ordered a 1/2hp submersible pump to go in the 200gal storage tank (fills up by city water):

https://www.amazon.com/gp/product/B00NTT2JW6

I would like to add a pvc CSV125 just after the pump and inside of the tank so if it spits it goes back into the water. Is this acceptable?

The CSV125 pressure has to be selected when ordered. I have a two storey house, should I use a 50psi or 40psi? I'm worried about the pump not being able to keep up to 50psi and getting the pressure tank to 60 psi. Pump chart is showing a maximum head of 150'.

I am going to try re-using my 44gal bladder tank. Using the calculator on their website (40 csv, 30/50 switch, 0.1gpm demand) it says it would take 7+ mins with the CSV125-1 and 2+ mins with the CSV125-3. Should I be using the CSV125-3 (3 gpm min flow)?

Just to add, being on an island we have to ship everything here and add import duty and VAT which can add 50%+ to the cost of things - so that's why I am trying to reuse things and going economical.

Thanks!

 

[Valveman]

150' is the same as 64 PSI. So, 30/50 with a 40 PSI CSV is the best that pump can do. You really need a 10 GPM, 1/2HP with a max pressure of 90 PSI or so. then you could even use the 60 PSI in the CSV125-1 with a 50/70 pressure switch. Sine the CSV125 is not adjustable, you simple turn the pressure switch down to get about 1 minute of run time, regardless of the size of tank. The only time you need the CSV125-3 is when the pump can only build 10 PSI more than the pressure switch shut off, as with a jet pump. But it still would not let you use a 40/60 switch with that particular pump.

 

[IslandFlyer]

I think we'd be OK with 40psi, as I think now the city pressure is 15psi.

Do you think I should return the 1/2hp pump and get a 1hp model? There is a also a 3/4 model, but I don't know if it will fit in the tank because it's longer as it's designed for a 3" pipe (although it has a higher head)

1 hp: (31.5" long), 207' head:
https://www.amazon.com/gp/product/B00NTT2JQM

3/4hp: (40.5" long), 270' head:
https://www.amazon.com/Hallmark-Industries-MA0459X-14A-S-Shell-Stainless/dp/B07BPC1XT6

 

[Valveman]

The 3/4 is the best fit. 270' of head is the same as 116 PSI, which would let you run 50/70 or more if you wanted.

 

[IslandFlyer]

My tank is only 38" in diameter and 36" tall.

Going to go with the 40psi CSV and 1/2hp pump. If the concept works and the pump fails in a year or three will upgrade then.

 

[Reach4]

My tank is only 38" in diameter and 36" tall.

Going to go with the 40psi CSV and 1/2hp pump. If the concept works and the pump fails in a year or three will upgrade then.

Flow inducer?

 

[Valveman]

My tank is only 38" in diameter and 36" tall.

Going to go with the 40psi CSV and 1/2hp pump. If the concept works and the pump fails in a year or three will upgrade then.

If your going with the pump that only builds 64 PSI, use the CSV125-3 in the 40 PSI version. With a 30/50 switch that make 14 PSI differential and the -3 valve will really give you about 1 GPM minimum, which is what you need.

 

[IslandFlyer]

Flow inducer?

Yes, going to build one around it as best I can.

 

[Fitter30]

You could cut the capacity of the booster pump with a 1/2"- 3/4"regulator piped between the discharge and suction of the pump. Dead head the pump and select one at a lower pressure. Check valve would be happier with 10 pipe diameters before and 5 after. Didn't see the brand and model of the pump just the 1 hp.

 

[IslandFlyer]

OK so I have the pump and picked up the CSV today!

In terms of mounting the pump - there is a 2" outlet at the top, can I run 1.25" through a T down into the tank and mount the pump vertically, using the T to help support? I know I will lose some tank capacity. I will still use a flow inducer sleeve and keep it an inch or two off the bottom.

Will the torque of the pump cause any issues? Should I use schedule 80 PVC from the pump?

 

[Valveman]

Yes that will work.

You can also lay the pump down if needed.

Torque is not an issue and in a cistern you can use whatever pipe you want. It is not like it is high pressure or would fall down a well if sch 40 glue joint came loose.