Shallow well pump to submersible questions

[AndrewM]

New member here. Ive read a lot of posts here in the past and in researching the project outlined below. I've got a 14 year old shallow well pump (1/2 hp) that started leaking a few weeks ago. The leak actually healed itself, but I'm not expecting it to last. Since purchasing this place 4 years ago I've been wanting to switch to a submersible pump. This leak has finally got the ball rolling. Our well is 87 feet of 4" galvanized casing. Static water level of 21' with one foot of drawdown at 50 gpm. All that info is from original paperwork circa 1973. We've got a 52 gal pressure tank and 30/50 switch. The current pump just doesn't have much capacity. It will run nonstop to supply two showers with measly pressure, nevermind watering the garden! I haven't checked for sure but I'm estimating 2-3 gpm max.
Ive got extensive DIY plumbing experience but this is my first attempt on the supply side. Ive got most of the project planned out already, including running electric to the well head. I just received shipment of a Grundfos 1/2 hp 3" well pump (115v) model 10SQ05-160. I really wanted to stick with 115v so I can power it with inverter generator if needed.
First actual question: I ordered a SS check valve to install directly above the pump before I realized this pump has a valve built-in. I read the sticky thread above about the disadvantages of multiple check valves. Should I return this valve or just install it immediately above the pump as intended? Most of the above thread seemed to refer to check valves above the water level.
I will have more questions I'm sure but that's all for now.

 

[Valveman]

The Grundfos has a very good check valve. I would just return the extra one. Good choice for the pump. But you are going from a pump that couldn't supply two showers, to one that will cycle itself to death if not running 4 showers at the same time. A 50 gallon pressure tank only holds 12 gallons of water, and will be filling and draining quickly while the pump cycles over and over. Adding a Cycle Stop Valve will not only solve the cycling problem and make your pump last several times longer than normal, but will give you strong constant 50 PSI with one shower by itself, or two, three, or four showers on at the same time. Without the CSV the pump will cycle and the pressure will fluctuate between 60 and 40 while taking a shower.

 

[Sponsor]

 

[AndrewM]

The Grundfos has a very good check valve. I would just return the extra one. Good choice for the pump. But you are going from a pump that couldn't supply two showers, to one that will cycle itself to death if not running 4 showers at the same time. A 50 gallon pressure tank only holds 12 gallons of water, and will be filling and draining quickly while the pump cycles over and over. Adding a Cycle Stop Valve will not only solve the cycling problem and make your pump last several times longer than normal, but will give you strong constant 50 PSI with one shower by itself, or two, three, or four showers on at the same time. Without the CSV the pump will cycle and the pressure will fluctuate between 60 and 40 while taking a shower.

I'm ahead of you there! I already ordered a csv. I never heard of them until I started reading up on well pumps. Once I wrapped my mind around how they work, I was sold. I also will be installing a new 40/60 switch. With a 52 gal tank where should I set the pressure on the csv?

I hope the pump is good, because it certainly wasn't the cheapest available. I'm planning to use 1" 160psi poly pipe for the well drop. Is that a good choice? I'll probably go with 40-45 feet.

 

[Valveman]

That pump can only build about 90 PSI of back pressure, so 160# pipe is more than adequate. With a 52 gallon tank that holds 12 gallons of water, setting the CSV1A at 55 PSI will take 3 minutes to put the last 3 gallons in tank and fill it from 55 to 60 PSI.

With a static level of 21' the back pressure will only be 81 PSI. If the water gets any deeper you will need the next larger pump.

 

[AndrewM]

That pump can only build about 90 PSI of back pressure, so 160# pipe is more than adequate. With a 52 gallon tank that holds 12 gallons of water, setting the CSV1A at 55 PSI will take 3 minutes to put the last 3 gallons in tank and fill it from 55 to 60 PSI.

With a static level of 21' the back pressure will only be 81 PSI. If the water gets any deeper you will need the next larger pump.

I appreciate the information. I'm waiting to tackle the project til the ground thaws, as I need to install conduit under a 10 ft wide section of concrete. I've got the pump and csv already, so I can do a temporary install on short notice if the current pump starts leaking again. Also need to plan out the details of plumbing up the csv, tank, etc.