Pressure tank connection to water pump

[Terry_on_Guam]

Hi, my name is Terry. I will be replacing an old Sta-Rite PLD-2L 3/4 HP deep well pump (convertible attachement to shallow well) with a Everbilt 3/4 HP shallow well pump (if HD has in stock, if not it may end up being a 1/2 HP pump). I would use an identical replacement, but there are limited options here on the island. The pump is fed by a water tank outside, so it's used to boost our water pressure, rather than to pump a well.

The existing setup doesn't have a tank "T", but instead a flexible hose from the tank to a "T" on the output of the pump (see attached pic). Is that acceptable or do I need to re-plumb my water closet with a "T" at the tank? It worked well for a couple years after we bought the house, but is no longer working. Logic tells me that it's just a "T" and could go anywhere....but I'm sure logic has gotten a lot of DIYers in trouble before, so I'm humbly asking for advice.

There doesn't appear to be a check-valve in line either, in the existing configuration what would stop the tank from sending water back into the pump? Should I add one?

I bought the house like it is, the previous owner was very much into DIY. A lot of his work is impressive and well thought out, but a few things here and there I question.

Thanks for taking the time to read and any advice is greatly appreciated.

- Terry

 

[Diehard]

Being a well pump design,there may be check valves in the suction line.

Also, you should be looking at flow at a particular pressure. Not just HP.
For example, I see the one you have is rated for 8 gpm at 40 psi.
A 1/2 HP would likely be a much lower gpm at comparable pressures.
So look closely before you jump.

You may want to consider putting this inquiry into the
Pumps and Wells section.

 

[Terry_on_Guam]

Diehard, thank you for the advice. I am researching that now. The pump is being used as a booster pump. I have city service water filling a large above ground holding tank (sometimes we lose water after typhoons) and the pump draws water from the tank via piping that runs under a slab of concrete, the height is probably about 5' (will use this in height in calculation). I have the system bypassed at the moment and still have decent pressure at the upstairs shower, but not that hotel sting-your-back type of pressure that I had with the pump.

Home Depot only has the 1/2 HP in stock, so the comparison should be easy, either it is enough pressure or not...will try to figure that out this morning.

My major concern is that I don't see a check valve anywhere... I'd think that something like that wouldn't be under the poured concrete.

A smaller concern is the state of buildup on the existing pump. The output of the pump goes to a sediment filter --> water softener --> chlorine filter --> UV filter, but pressure inside the house was great when the pump worked. Would adding another large sediment filter before the pump impede on it maintaining pressure (or perhaps I could add one before the holding tank)? All of the buildup on the existing pump has me thinking that the inside of it is gunked up.

Will try to relocate this to the thread that you recommended.

Thanks again!

Terry

 

[Terry_on_Guam]

Can a Moderator or Admin assist me in moving this thread to the "Wells and Pumps" discussion board? I can't figure out how to move it over from my phone.

 

[FishScreener]

Pumps like certain hydraulic conditions, which are shown on what is called the pump curve. You might throttle the pump by adding a suction side filter. But so long as the pump is running near it’s curve you’ll be ok. Unless the suction head gets high enough to cause cavitation.

If the water level in the storage tank, is higher than your pump, you should be ok. So long as you size the filter and piping large enough to keep the pressure loss low on the suction side you’ll be ok.

 

[Terry_on_Guam]

FishScreener, thanks for some more great advice! The holding tank is big enough for an extended water outage, probably close to 1000 gallons, and the outlet is at the bottom, so a pre-tank filter shouldn't affect the pump draw at all unless my teenage son greatly extends his, already long, showers [emoji37].