Pascal's Law

In the physical sciences, Pascal's law or Pascal's principle states that "pressure exerted anywhere in a confined fluid is transmitted equally in all directions throughout the fluid."[1]

where
ΔP is the hydrostatic pressure (given in pascals in the SI system), or the difference in pressure at two points within a fluid column, due to the weight of the fluid;
ρ is the fluid density (in kilograms per cubic meter in the SI system);
g is acceleration due to gravity (normally using the sea level acceleration due to Earth's gravity in meters per second squared);
Δh is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in meters in SI).
The intuitive explanation of this formula is that the change in pressure between two elevations is due to the weight of the fluid between the elevations.
Note that the variation with height does not depend on any additional pressures. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid. Equation: (P1)(V1) = (P2)(V2)


Applications

• The underlying principle of the hydraulic press
• Used for amplifying the force of the driver's foot in the braking system of most cars and trucks.
• Used in artesian wells, water towers, and dams.
• Scuba divers must understand this principle. At a depth of 10 meters under water, pressure is twice the atmospheric pressure at sea level, and increases by about 105 kPa for each increase of 10 m depth.

quoted from Wikipedia

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Also called Pascal's Principle

Pascal's law — developed by French mathematician Blaise Pascal — states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container.

Definition of pressure:
If F is the magnitude of the normal force on the piston and A is the surface area of a piston, then the pressure, P, of the fluid at the level to which the device has been submerged as the ratio of the force to area.



Since the pressure is force per unit area, it has units of N/m2 in the SI system.
Another name for the SI unit of pressure is Pascal (Pa)



An important application of Pascal's law is the hydraulic press. A force F1 is applied to a small piston of area A1. The pressure is transmitted through a liquid to a larger piston of area A2. Since the pressure is the same on both sides, we see that P = F1/A1 = F2/A2. Therefore, the force F2 is larger than F1 by multiplying factor A2/A1. Hydraulic brakes, car lifts, hydraulic jacks, and forklifts all make use of this principle.


quoted from Engineering.com



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Pascal's Picture

Fundamental Physical Principles of Hydraulics : Part 1

Fundamental?..Any connection with mental disorder?...hahaha..Maybe if you don't master the fundamental...


What is the fundamental physical principles of Hydraulics?

Pressure

Back to the basic of hydraulic mentioned before; Hydraulic is the science of forces and movements transmitted by means of liquids

It belongs alongside hydro-mechanics. A distinction (phew..so many distinction in this blog) is made between hydrostatics and hydrodynamics.

What is Hydrostatics? it can be defined as dynamic effect through pressure times area (P x A) or in simple words, pressure that exerts statically.

Example: You as a good and cool father is happily organized a very extravaganza birthday party for your cute little princess. Since it is a super extravaganza event, so your wife ask you to buy a bunch of balloon , complete with a bear and rabbit faces on it. Well, without balloon it can't be called as extravaganza balloon. After exhausted for completing blowing manually th 1455th balloon of the year, you take one of it. You just staring into it. The balloon is nicely blown, resulting nice shape...Well..the connection here, the air (+ your unfiltered saliva) inside the balloon is a hydrostatic force. The air producing force that allowing the balloon to expand into the shape...that is it! the hydrostatic...

Hydrodynamics can be defined as dynamics effect through mass times acceleration ( m x a)..simple example..a turbine which rotating due to the impact produce by high speed moving fluid ( normally can be found at the dam)

Force and Area

Force normally noted as F symbol and area with A. The connection between Pressure, Force and Area are shown in the basic formula; P=F/A.However, pressure is different owing to the different size of area.

Pressure Transmission

Theoretically, if a force F1 acts via an area A1 on an enclosed liquid, a pressure P is produced which extends throughout the whole liquid (Pascal's Law).

Owing that the fact hydraulic system operate at very high pressures, it is possible to neglect the hydrostatic pressure. Therefore, when calculating the pressure in liquids, the calculations are based purely on pressure caused by external forces. Short said, for the solid bodies,the expression formula is ; P= F/A

Power Transmission

Bear in mind, and always remember that in a closed system the same pressure applies at every point (this is according the theory whereas for 100% system efficeincy). Thus, the shape of the container has no significant.

The fluid pressure in a system consists of a pair of piston with areas noted as A1 and A2, and two forces which can be noted as F1 and F2, can be describes by means of the following equations:

P1 = F1 / A1 and P2 = F2/A2

And when the system are in equilibrium:

P1 = P2

When the equation is already balanced, the following formula is produced:

F2/A2 = F1 / A1

Small forces from the piston can produce larger forces by increasing the area of working piston surface. This is the fundamental principle which is applied in every hydraulic system from the simple jack to complicated lifting platform. The force F1 must be sufficient to overcome the load resistance...


Easter Egg!!

The Part 1 ends here. As to give clear picture, I will provide simple problem solving on how this hydraulic equation works. This is the bonus of the Part 1....


Problem Statement:

A New Kia Forte SX1.6 has been sent to the workshop for servicing. The vehicle need to be lifted by the hydraulic jack. The approximate weight for the Kia Forte is around 1500kg. The main specs of the jack is it handle's piston area are 40cm square while the platform cylinder surface area are 1200cm square What force need to be applied at the jack's handle?

Solution:

Assume:


Step 1:
F1 = force need to be applied to the jack's handle
A1 = 40 cm square = 0.004m square

F2 = force from Kia Forte
A2 = 1200 cm square = 0.12m square


Step 2:
Find the F2 value first;

Basically; F = ma = mg

Given weight: 1500kg

So:

F2 = mg
= (1500)(9.81)
= 14 175 N


Step 3:

Now to find the F1 value;

We know that:

P1 = P2

F1/A1 =F2/A2

Thus;

F1=(F2 x A1) / A2

F1 = (14 175N x 0.004m square) / 0.12m square

F1 = 490.5N

Hydraulic Cylinder Force Over Pre Set Limit

One fine morning, where the bird chirping happily, and the sunny shine nicely...

Mr.X: (reading a SMS that just arrived)

hello brother! We had problem with the cylinder hydraulic, the force on the operational side is going higher beyond preset,resulting some parts of the machine damaged. our team has been doing troubleshooting since last night...suspected EMG Valve problem- Mr. XX

Mr.X: hrmm...what happened here? (asked him once arrive at the crime-scene)

Mr.XX:well the force still go beyond the limit. We suspected the EMG problem. We already take out the EMG valve out, and service it by cleaning all the suspected dirt on the hole. We also already has keep on setting the spool..but the problem still remain unsolved..

Mr.X: well...let me ask the operator first..has you ask the electrical team to check on their system?

Mr. XX: they are checking their programming at the MCC room..

Mr. X: Alrite!

(after collecting some information and finding the root cause of the problem)

Mr. X: (thinking intensely to solve the problems)

Why do they all focusing on the EMG valve? Is it because only the cylinder are connected to the EMG Valve? But the main problem is the force overshooted from the pre set limit. EMG Valve only responsible on controlling directional, speed and steps..hrmm..suspected not only the EMG Valve problem...the main suspected problem is the PRV (Pressure Regulator Valve)..ah ha..let we try to change this first!

Mr.X: Ok my supervisor..lets change this PRV first before we try to change the EMG valve..he is the main crime suspect...mwahaha

Mr. Supervisor: Alrite...

While changing the PRV, Mr.X asking the ElectricMan on some electrical stuff

Mr. X: Yo LetricMan...want to ask something..since the problems occur after the unsuspected electricity power supply shutdown..do the any chances for the EMG Valve socket to damage due to overflow electricity after start-up?

LetricMan: Well..this can't be happen..because we had equip circuit breaker to the EMG Valve circuit in order to protect them..Let me show you...here is the circuit breaker...if the current overshoot during startup....the circuit breaker will trip and disallow the current to flow to the EMG Valve circuit..

Mr. X:i see...

After installation completion...

Mr. Supervisor: Ok..let the operator test...









After a few test run..the operator confirm the system back to normal..and the operation resume...



Problem: PRV malfunction
Cause: Suspected the PRV's spool damaged due to wear and tear
Countermeasure: Replace the PRV with a new set


CASE CLOSED

What Is Hydraulic?

What is Hydraulic?

There are various definition by various parties by various time and by various place (uh-oh..how much various duh?!)

• moved or operated or effected by liquid (water or oil); "hydraulic erosion"; "hydraulic brakes"
• of or relating to the study of hydraulics; "hydraulic engineer" (by:wordnetweb.princeton.edu/perl/webwn)

• Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. ...(by:en.wikipedia.org/wiki/Hydraulic)

• Pertaining to water; Related to hydraulics (by: en.wiktionary.org/wiki/hydraulic)

• hydraulics - fluid mechanics: study of the mechanics of fluids (by:wordnetweb.princeton.edu/perl/webwn)

Ok..that is some definition can be found if you asked Uncle Google

Ok..as simple conclusion:

Hydraulic is the forces and motion generation, using the hydraulic fluids which the fluid act as a representative for the medium of power transmission

Hydraulic will 100% related with fluid ( the fluid terms here including water and oil, except air, because air is belong to pneumatic system)

Application of hydraulics:

Well..beyond the Industrial Era, which more factory has been developed rapidly through the years, the hydraulic system are also has been developed years by years..to improve it efficiency and reliability...

Since we are in modern era (an era where you can just Around The World in 80 Hours)...basic distinction of modern automation hydraulic technology is made between:

• stationary hydraulic
• mobile hydraulic

Mobile hydraulic systems move on wheels or tracks, for example, unlike stationary stationary hydraulic systems which remain firmly fixed in one position. A characteristic feature of mobile hydraulics is that the valves are frequently manually operated. In the case of stationary hydraulics however mainly solenoid valves is used......

"Sir..I,m puzzle...what is the mean of manually operated and those solenoid valve and bla bla..."

"Simple son, mobile hydraulic...errr..look out through the window....near that clothing warehouse..no!..don't look at those hot chick model..look at the moving forklift...can you see how its working?..it can lift up those goods by using its pair "fork" rite?..."

"Andd????.."

"The mechanism to lift there is using hydraulic system..consist of one cylinder..to control the movement of the cylinder..look at the driver's hand while he is lifting the goods..can you see he's triggering forward and backward a few knob?"

"Uh oh..yes..yes..I can see it Sir!"

"Well..that is what valves are frequently manually operated mean...the trigger somehow is connected to directional valve which control the movement and direction of the hydraulic cylinder...and why it's called as mobile hydraulic?"

"Because its mounted to the moving object...fuhh..now only I can see all those stars gone above my head!"


(story of the day 1)

The following application areas are important for stationary hydraulics:

• Production and assembly machines of all types
• Transfer lines
• Lifting and conveying devices
• Presses
• Injection moulding machines
• Rolling Lines
• Lifts

Typical application fields for mobile hydraulics:

• Construction machinery
• Tippers, excavators, elevating platform
• Lifting and conveying devices
• Agricultural machinery
• Transportation

Some best-value-added using hydraulic systems are:

1. Transmission of large forces using small components
2. Precise positioning
3. Start-up under heavy load
4. Even movements independent of load
5. Smooth operational and reversal
6. Good control and regulation
7. Favorable heat dissipation
8. Standardize around the world

Parts of Bad things about hydraulics:

1. Pollution of the environment by waste oil
2. Dirt sensitive
3. Danger resulting from excessive pressures
4. Temperature dependence
5. Unfavorable efficiency factor

Welcome!

Welcome visitor to this blog. The main purpose of developing this blog is to share, either directly or indirectly,1 way connection or 2 way connection, all the infos, tips, tricks, troubleshooting guide of Hydraulic System.

Why Hydraulic system? Do you know most of industries in the world (especially heavy industries) are 85% or more relies on this hydraulic system, as parts to operate their machines, moving goods from other point to another point and much more what hydraulic system can do.

Be hold! Get ready to be amazed what is the true capability of this hydraulic system. From simple hydraulic system to much more complicated system, from traditional hydraulic system to converting into electro-hydraulic system.

The way of conveying info via this blog? I'll try to run away from typical method of delivering info..which to me will make people bored while seeking for info..


So, fasten your seat belt, hold your nerve, hold the wheel tight, and go!

WELCOME TO HYDRAULIC HUB BLOG...

the only place where you will never get bath by the hydraulic oil!=p