lbiasotto
Builder Developer
Hello, I have arrived at this forum for some advice. I am a general contractor and not an expert on plumbing or pumps. I am hoping that the experts on this forum will troubleshoot my proposed design which is primarily based on my own research.
Here goes:
This system will be built in Puerto Rico, on the coast, where salt corrosion is high and reliable servicemen are scarce. My ultimate goal is to have a reliable system with good if not constant water pressure.
The system will support a 3 unit, 2 story apartment house. 2 units have one bath, the 3rd unit has 3 baths, all have kitchens. I intend to have a separate cistern for irrigation so I can capture rain water.
There is municipal water available, but the water pressure is inadequate. Water will not push to the second floor at all. Most homes in the area have a plastic 800 gallon cistern with a jet pump. it seems that these systems have a limited life given the salt air. And due to issues with installation most are hard to reprime if stopped.
Since I will be 1500 miles away, I want a very reliable system. So my thought was to use a submersible well pump. I also dont want to be out of water given that the municipal system goes down regularly. Thus the large capacity of the cistern (4000 gal)
My proposed system:
We intend to install an 8'x8'x8' underground cistern fed by the municipal water. The construction will be reinforced concrete sealed with food grade epoxy. I will put a pit in the bottom of the cistern about the size of a drywall bucket. Again, sealed concrete. I will then set a 4" well pipe into the bottom of the pit, set directly into concrete. We will drill numerous holes into the bottom of the pipe for water intake. We will then drop a 4" well pump into the pipe. The cistern will be covered with dirt with only the well pipe sticking out of the ground.
I located a Goulds distributor who sized a 18GS 1.5 hp pump. 230V, single phase is available. They also recommended the BF20 balance flow converter. Based on my reading herein, I have abandonded the idea of the BF20.
At face value, this application will function like a standard well pump design. But given that we are dealing with an 8' deep cistern, and not a deep well, the head pressure will be low. We intend to use 1 1/4" pipe from the pump with about 100' to the ground floor level of the house.
Other considerations include needing a way to automatically shut off the pump if the sistern runs dry (float switch?). Feeding water to the irrigation cistern (which will have its own pump) but only when the irrigation cistern is low. And regulating pressure.(cycle stop valve? bladder tank size?)
Does the sizing of the 18GS 1.5 pump seem correct? Does this seem like a reasonable way to proceed? I like the idea of a submersible to avoid priming and corrosion issues (correct assumption?).
In the end we assumed a peak need of 28 GPM at about 60 PSI.
Hope this makes sense. Your comments are appreciated.
Larry
Here goes:
This system will be built in Puerto Rico, on the coast, where salt corrosion is high and reliable servicemen are scarce. My ultimate goal is to have a reliable system with good if not constant water pressure.
The system will support a 3 unit, 2 story apartment house. 2 units have one bath, the 3rd unit has 3 baths, all have kitchens. I intend to have a separate cistern for irrigation so I can capture rain water.
There is municipal water available, but the water pressure is inadequate. Water will not push to the second floor at all. Most homes in the area have a plastic 800 gallon cistern with a jet pump. it seems that these systems have a limited life given the salt air. And due to issues with installation most are hard to reprime if stopped.
Since I will be 1500 miles away, I want a very reliable system. So my thought was to use a submersible well pump. I also dont want to be out of water given that the municipal system goes down regularly. Thus the large capacity of the cistern (4000 gal)
My proposed system:
We intend to install an 8'x8'x8' underground cistern fed by the municipal water. The construction will be reinforced concrete sealed with food grade epoxy. I will put a pit in the bottom of the cistern about the size of a drywall bucket. Again, sealed concrete. I will then set a 4" well pipe into the bottom of the pit, set directly into concrete. We will drill numerous holes into the bottom of the pipe for water intake. We will then drop a 4" well pump into the pipe. The cistern will be covered with dirt with only the well pipe sticking out of the ground.
I located a Goulds distributor who sized a 18GS 1.5 hp pump. 230V, single phase is available. They also recommended the BF20 balance flow converter. Based on my reading herein, I have abandonded the idea of the BF20.
At face value, this application will function like a standard well pump design. But given that we are dealing with an 8' deep cistern, and not a deep well, the head pressure will be low. We intend to use 1 1/4" pipe from the pump with about 100' to the ground floor level of the house.
Other considerations include needing a way to automatically shut off the pump if the sistern runs dry (float switch?). Feeding water to the irrigation cistern (which will have its own pump) but only when the irrigation cistern is low. And regulating pressure.(cycle stop valve? bladder tank size?)
Does the sizing of the 18GS 1.5 pump seem correct? Does this seem like a reasonable way to proceed? I like the idea of a submersible to avoid priming and corrosion issues (correct assumption?).
In the end we assumed a peak need of 28 GPM at about 60 PSI.
Hope this makes sense. Your comments are appreciated.
Larry