Principles Of Pressure Flashcards
What determines the speed at which a fluid travels through a hose or pipe?
The pressure upon that fluid and the size of the orifice through which it is flowing. (This speed is called VELOCITY)
What is the first principle of fluid pressure?
Fluid pressure is perpendicular to any surface on which it acts.
How is the first principle of fluid pressure illustrated?
By a vessel having flat sides and containing water, where pressure exerted by the weight of the water is perpendicular to the walls.
What does the second principle of fluid pressure state?
Fluid pressure at a point in fluid at rest is the same INTENISY in all directions. (Second Principle) Hydrostatic Testing
What is the third principle of fluid pressure?
Pressure applied to a confined fluid is transmitted equally in all directions.
What happens to the pressure readings in a confined fluid when pressure is applied?
All gauges will register the same pressure if they are on the same grade line with no changes in elevation. (3rd Principle)
What is the effect of a closed standpipe height on pressure readings?
A gauge at the top reads lower pressure than a gauge at the bottom due to the weight of the water in the standpipe.(3rd Principle)(example appears to describe 4th principle (key word is “closed”))
What is the fourth principle of fluid pressure?
The pressure of a liquid in an open vessel is proportional to its depth.
How is the fourth principle illustrated?
By comparing the pressure at the bottoms of three vertical containers with different water depths.
What is the fifth principle of fluid pressure?
The pressure of a liquid in an OPEN vessel is proportional to the Density of the liquid.
How does the fifth principle relate to mercury and water?
Mercury is 13.55 times denser than water, a container with 1” of mercury creates the same pressure on the bottom of the container as 13.55” of water.
Fill in the blank: In reference to the 5th principle, the pressure of a liquid in an open vessel is proportional to its _______.
Density. (5th Principle)
True or False: Fluid pressure can act in any direction on a surface.
False
According to the FIRST principle fluid pressure is perpendicular to any surface on which it acts
What devices are installed in standpipe systems for high-rise buildings?
Pressure-regulating devices. This is the example given for the THIRD PRINCIPLE.
What is the relationship between liquid depth and pressure in an open vessel?
Pressure increases with depth.
What happens to the pressure at the bottom of a container as the depth of liquid increases?
It increases proportionally.
What does the Sixth Principle state about liquid pressure?
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel.
How is the Sixth Principle illustrated?
By observing water in several different-shaped containers with the same cross-sectional area at the bottom and the same height.
True or False: The shape of a vessel affects the pressure at the bottom if the height and cross-sectional area are constant.
False
Fill in the blank: The pressure at the bottom of a liquid vessel is determined by its _______ and _______.
[height], [density of the liquid]
