Pump pressure
Pump pressure
(OP)
Hello all.
I’ve worked on trying to find this equation all day and am desperate for help 🤣.
I have a 200’ 3/8” ID hose, 100’ of it is totally vertical and the other 100’ is laying on the ground running to a pump 12” off the ground. The hose is some sort of plastic, there is no writing on the hose to verify what it is. The grease has a 80 minute viscosity and the temperature is 40 deg F. In the event that hose is fully primed, how much pressure would it take to overcome that static friction?
Thanks in advance, please share your work!
I’ve worked on trying to find this equation all day and am desperate for help 🤣.
I have a 200’ 3/8” ID hose, 100’ of it is totally vertical and the other 100’ is laying on the ground running to a pump 12” off the ground. The hose is some sort of plastic, there is no writing on the hose to verify what it is. The grease has a 80 minute viscosity and the temperature is 40 deg F. In the event that hose is fully primed, how much pressure would it take to overcome that static friction?
Thanks in advance, please share your work!
RE: Pump pressure
https://www.engineersedge.com/fluid_flow/kinematic...
Use 200 feet for the length when calculating friction loss.
Plastic has an absolute roughness of around 0.0005 in/in
Add 100 feet of head, for the lift static pressure. You will need the density of the grease.
PSI = 100 ft lift x density pcf /144
There are some friction loss calculators in the additional links on that Web page.
Let us know if you need more help.
RE: Pump pressure
The unit is Saybolt I believe .
Consider the link to convert in centistokes : https://www.coleparmer.com/tech-article/viscosity-...
Density is needed to convert to dynamic viscosity .
Pierre
RE: Pump pressure
RE: Pump pressure
Static head is your 100ft x density. Your looking about 50 to 55 psi.
"Static friction" is a strange term.
Without flow there is no friction losses. There may be some sort of pressure required to break the gelling of the grease, but that isn't viscosity.
Now if the question is about what flow you will get or what pressure you need for a certain flowered then you either need your flow rate or the discharge pressure of the pump.
If this is grease I guess this is some sort of P D pump??
If you describe what your issue is or what you're trying to do will help everyone. When you wake up.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pump pressure
RE: Pump pressure
That's as close to treacle as you want to be.
I have a feeling grease at that viscosity is anon newtonian fluid so need to have some shear going on to flow and then the pressure drop reduces.
I don't fully understand what a 1:140 pump is but sounds like a pressure ratio.
A house that length is not ideal. The risk is that the pressure pulse simply expand the hose and doesn't move the grease down the tube.
The only real way is to test it in action. I suspect you will need 3 ro 4 times the minimum static pressure to get any grass found down that hose. But the hose may be not the right thing.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pump pressure
RE: Pump pressure
I think your grease is gelling due to the cold and you need a large differential pressure per ft of hose to break the gel. Once it breaks the pressure required could fall significantly if you can maintain flow.
These things are not easy to calculate without good data on the fluid.
What is your 80 minutes of viscosity based on in terms of temperature?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pump pressure
Some of these things you can't calculate and once you get into gel break pressure you need test data really with your particular hose and grease.
In my units, a 60m long 10mm ID hose full of "grease" at 5C is as close to bitumen as you will get. If you've tried 2000psi differential and it still won't move its time to find a different method. A bigger hose might help but then you need to fill it with grease.
Or trace heat and insulate it?
Or make your hose a LOT shorter - like 5m.
Let us know hw you get on.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pump pressure
RE: Pump pressure
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.