Understanding pump charts, tables and specs.

[Rldev]

I am comparing 2 jet pumps that are comparable in price. But I believe I am misunderstanding the graphs and tables.

Franklin Electric Versjet FVJ1CI-P (1HP)
Graph

VersaJet Pro Cast Iron Shallow Well Jet Pump

The VersaJet Pro shallow well jet pump covers a variety of performance needs. Included is our nozzle replacement system, which makes maintenance a breeze.

www.franklinwater.com

GOULDS J10S (1HP)
Table

https://assets.unilogcorp.com/267/ITEM/DOC/Goulds_J10S_Specification_Sheet.pdf

Looking at the performance graph and table, the Franklin seems like it can move a lot more water at a match PSI of 60. Am I misunderstanding the charts?

Goulds
at 5ft Lift and 60 PSI, it will move 9.9 gallons per minute

Franklin (with high pressure nozzle)
at 5ft lift and 60 PSI, it will move 16 gallons per minute. The dropoff from 3/4HP model from the 1HP model is hard to believe.

This can't be correct. You would need a 1.5HP Goulds to match the pressure and output of a 1HP Versajet. What am I getting wrong here?

 

[wwhitney]

Per the Versajet spec sheet table, for 5' of suction head and 60 psi discharge pressure, the FVJ1CI-P will do 11.6 gpm with the standard nozzle and 15.5 gpm with the high pressure nozzle. So the former case, at least, is not so different from the Goulds's 9.9 gpm.

As to whether those numbers are plausible or not, I have no ability to comment. But I can confirm you are reading the tables correctly. : - )

Cheers, Wayne

 

[Sponsor]

 

[Reach4]

You are reading things right. The Franklin (with high pressure nozzle) will outperform substantially the Goulds J10S with the standard nozzle at 60 PSI.

If running a 40/60 switch, the GPM performance at 40 PSI is more important, but the published numbers still show the Franklin outperforming.

I expect the Goulds only being shown with one nozzle + venturi is a big part of that. The fact that it ships with a set of 3 nozzles is a plus for them. With the Goulds, there is probably a nozzle + venturi that improves performance at higher pressures. But that would take extra study to select, and a significant extra cost to buy.

Some companies are more conservative in their numbers. Some companies stretch their numbers. Not saying Franklin is doing that, but it could be the case.

 

[Rldev]

A stupid question, but do I deduct my city pressure from my desired pressure set point when looking at these charts and tables? Say I want to achieve 60 psi. If my home pressure is 20 psi, then I should be looking at the chart/table numbers for 40 psi?

 

[Reach4]

A stupid question, but do I deduct my city pressure from my desired pressure set point when looking at these charts and tables? Say I want to achieve 60 psi. If my home pressure is 20 psi, then I should be looking at the chart/table numbers for 40 psi?

Yes, but not the static pressure. You would want the pressure while the water is flowing at the flow rate you are calculating for.

Any thoughts on the pumps I pointed to in https://terrylove.com/forums/index.php?threads/city-water-low-static-pressure-and-low-flow.112546/ #12? Those are not jet pumps. While they come in higher power versions, I think 1/2 HP would work nicely as a booster. Not sure how much quieter that would be. But no jet. A non-jet pump is faster to get up to pressure. With a jet pump, you set the air precharge lower so that pressure tank can deliver the water while the jet pump builds flow.

 

[Rldev]

I have to look more closely at it. I was intrigued. For whatever reason I assumed centrifuge pumps were not as good for creating pressure. I want to go with a CSV setup. Would it matter in this case? I know F & W is a great brand too.

 

[Reach4]

I have to look more closely at it. I was intrigued. For whatever reason I assumed centrifuge pumps were not as good for creating pressure. I want to go with a CSV setup. Would it matter in this case? I know F & W is a great brand too.

A jet pump has a one-stage centrifugal pump in it that powers the jet. The jet then somehow trades volume for pressure. Sounds backwards, doesn't it.

If the jet/nozzle on a jet pump clogs, the pump puts out about 20 psi typically.

 

[Rldev]

That's why Centrifugal pumps are called "Magical".

 

[Reach4]

centrifugal adjective - Definition, pictures, pronunciation and usage notes | Oxford Advanced Learner's Dictionary at OxfordLearnersDictionaries.com

Definition of centrifugal adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

www.oxfordlearnersdictionaries.com

That has two British and one American pronunciation.

I find hearing the British pronunciation a bit odd.

That's why Centrifugal pumps are called "Magical".

I have heard them called counterintuitive, but you are the first I have seen use "magical".