# Pressure loss

### Users who are viewing this thread

##### New Member
If I buy a 1hp jet pump to replace the 1 hp city pump what size pressure tank is needed? My 2 story house is about 50ft higher on a hill and 280ft way from the pump. 1” supply line.

##### New Member
If I buy a 1hp jet pump to replace the city 1 hp pump what size pressure tank will I need. My 2 story house is 280‘ away on a 50’ hill. They supply line is 1”.

#### Valveman

##### Cary Austin
Staff member
The 50' elevation to the house means you need to add 20 PSI to the pump pressure. So, instead of 40/60 you need a 60/80 pressure switch. Even at that pressure you still only need a 10 gallon size pressure tank when using a CSV like with the PK1A kit. Without the CSV I would use an 86 gallon size pressure tank, which still won't do as good a job as the CSV and small tank.

##### New Member
Someone told me I will burn up my pump with a 1” supply line going 300’ and 50’ uphill. I should increase my supply line to 1-1/4” to 2’’. Is they any true to that? if so what size and would a 1 hp pump still work?

#### Reach4

##### Well-Known Member
http://irrigation.wsu.edu/Content/Calculators/General/Pipeline-Pressure-Loss.php may help with your decision on pipe size. You pressure loss will be the sum of the 50 ft head (about 21 psi) + the dynamic pressure drop due to flow.

If the pressure switch and pressure tank, I would plug 20 gpm into the calculator. You will not have that much flow, but you want to not have a lot off pressure drop in the showers when somebody flushes a toilet or runs the washing machine.

If the pressure tank and pressure switch were up top, I would plug 10 gpm into the calculator.

##### New Member
The 50' elevation to the house means you need to add 20 PSI to the pump pressure. So, instead of 40/60 you need a 60/80 pressure switch. Even at that pressure you still only need a 10 gallon size pressure tank when using a CSV like with the PK1A kit. Without the CSV I would use an 86 gallon size pressure tank, which still won't do as good a job as the CSV and small tank.
Someone told me I will burn up my pump with a 1” supply line going 300’ and 50’ uphill. I should increase my supply line to 1-1/4” to 2’’. Is there any true to that? if so what size line and would a 1 hp pump still work?

#### Fitter30

##### Well-Known Member
Have any idea what the difference in height is switch to house. 2.31 ' per lb of pressure. 150' rise add 65 lbs to your switch cut in and cut out. Want 40 - 60, 105 - 125. Going to need a different control.,

#### LLigetfa

##### DIYer, not in the trades
Have any idea what the difference in height is switch to house. 2.31 ' per lb of pressure. 150' rise add 65 lbs to your switch cut in and cut out. Want 40 - 60, 105 - 125. Going to need a different control.,
OP said 300 foot run and 50 foot rise. With .43 PSI per foot, that would be a 21.5 PSI drop. That means you need a pump that can produce 21.5 more PSI than the desired PSI at the top of the hill, so if 80 PSI is desired, the pump would need to produce 101.5 PSI. I don't think you will find a jet pump that can do that.

Pressure drop over the 300 feet needs to be calculated based on pipe size and GPM. There are online calculators for that. If inline resistance drops the GPM, the inline resistance will drop since it increases with GPM so as long as the pressure switch cut-out is so high as to drop the GPM to less than 1, it should not dead-head.

#### Reach4

##### Well-Known Member
I was thinking the jet pump was just adding pressure to what the city provides.

##### New Member
I was thinking the jet pump was just adding pressure to what the city provides.
I am boosting city water. I ordered a 1 1/2hp gourd j15s and a pk1a with a pressure switch 60/80.

#### Valveman

##### Cary Austin
Staff member
I am boosting city water. I ordered a 1 1/2hp gourd j15s and a pk1a with a pressure switch 60/80.
Please let us know how it works.

#### Fitter30

##### Well-Known Member
Talk to a pump company with using a booster pump alone with your jet and maybe another expansion tank in the house.

#### Reach4

##### Well-Known Member
I was thinking maybe a multi-stage booster centrifugal pump rather than a jet pump. I have no experience with either.

#### LLigetfa

##### DIYer, not in the trades
I was thinking the jet pump was just adding pressure to what the city provides.
True, but it is not documented here what min and max pressure might be available down at the curb.

##### New Member
ok Canceled the pump order, still getting the pk1a. Will see if I can get the city pressure tomorrow.

#### LLigetfa

##### DIYer, not in the trades
Here is a technical document on that pump.

#### Valveman

##### Cary Austin
Staff member
Sorry for the delay. That J15S pump will work fine. Unlike many other jet pumps that one can build 83 PSI max. As long as the city pressure is at least 10 PSI that pump will work fine with a 60/80 switch and a CSV setting of 70 PSI. If you don't have at least 10 PSI coming from the city you will have different problems and will probably require a cistern storage tank.

##### New Member
Measures the pressure before the pump it is 29 psi. What are your recommendations for a pump. The one I have now measured 67psi at the house when it finally kicks on.

#### Valveman

##### Cary Austin
Staff member
Like I said, as long as there is at least 10 PSI from the city the J15S is my first choice.

#### LLigetfa

##### DIYer, not in the trades
I ordered a 1 1/2hp gourd j15s and a pk1a with a pressure switch 60/80.
That should produce a constant pressure of around 50 PSI, so less than what your current pump produces. Is it a multi-level home or a bungalow? At what elevation is the 67 PSI measured? Remember that you lose .43 PSI per foot of elevation and depending on the pipe diameter, you may also have friction loss.

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