Principles of Pressure and Friction Flashcards
6th Principle of pressure
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel.
1st Principle of pressure
Fluid pressure is perpendicular to any surface on which it acts.
2nd Principle of pressure
Fluid pressure at a point of rest is the same intensity in all directions.
The pressure of a liquid in an open vessel is proportional to the density of the liquid.
5th Principle of pressure
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel.
6th Principle of pressure
5th Principle of pressure
The pressure of a liquid in an open vessel is proportional to the density of the liquid.
3rd Principle of pressure
Pressure applied to a confined fluid is transmitted equally in all directions.
Fluid pressure at a point of rest is the same intensity in all directions.
2nd Principle of pressure
4th Principle of pressure
The pressure of a liquid in an open vessel is proportional to its depth.
The pressure of a liquid in an open vessel is proportional to its depth.
4th Principle of pressure
Pressure applied to a confined fluid is transmitted equally in all directions.
3rd Principle of pressure
Fluid pressure is perpendicular to any surface on which it acts.
1st Principle of pressure
Types of pressure
Atmospheric Pressure, Head Pressure, Static Pressure, Normal operating pressure, Residual Pressure, Flow pressure (velocity pressure)
Atmospheric pressure
Pressure surrounding the earth that has depth and density. 14.7psi at sea level
Head Pressure
Height of water above discharge. 0.434 per ft elevation
Static Pressure
Stored potential energy available in a water system. At rest.
If all other conditions remain the same, friction loss varies directly with the length of the hose. (Set gpm in one hose diameter the FL is proportional to the leght of the hose)
First Principle of Friction Loss
When hoses are the same size, friciton loss varies approx. with the square of the increase in velocity of the flow. (Double flow/quadruple FL, Triple flow/9x FL)
Second principle fo Friciton Loss
For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose.
2.5^5=97.66
3^5=243
97.66/243=0.4
Meaning for the same flow the 3” would have 60% less friction than the 2.5”
Third Principle of Friction loss
For a given velocity, friction loss is approximately the same, regardless of the pressure on the water.
In other words a 1.75” flowing 150 gpm @ 100 psi and at 150psi will have the same FL
Fourth Principle of Friction loss.
