Inst ToolsInst ToolsInst Tools
  • Courses
  • Videos
  • Q & A
    • Interview
      • Instrumentation
      • Electronics
      • Electrical
      • Practical Questions
    • MCQ
      • Instrumentation MCQ
      • Electrical MCQ
      • Electronics MCQ
      • Control Systems MCQ
      • Analog Electronics MCQ
      • Digital Electronics MCQ
      • Power Electronics MCQ
      • Microprocessor MCQ
      • Multiple Choice Questions
  • EE
    • Electronics
      • Electronics Q & A
      • Electronic Basics
      • Electronic Devices & Circuits
      • Electronics Animation
      • Digital Electronics
    • Electrical
      • Electrical Basics
      • Electrical Q & A
      • Power Electronics
      • Electrical Machines
      • Electrical Animation
      • Power Systems
      • Switchgear & Protection
      • Transmission & Distribution
  • Measure
    • Control Valves
    • Calibration
    • Temperature
    • Pressure
    • Flow
    • Level
    • Analyzers
    • Switches
    • Vibration
    • Solenoid Valve
  • Control
    • PLC Tutorials
    • Control Systems
    • Safety Instrumented System (SIS)
    • Communication
    • Fire & Gas System
  • More
    • Design
    • Tools
    • Animation
    • Basics
    • Formulas
    • Standards
    • TextBooks
    • Common
    • Software
    • Excel Tools
    • Erection & Commissioning
    • Process Fundamentals
    • Videos
    • Books
Search
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Reading: Calculate Hydraulic System Fluid Pressure
Share
Notification Show More
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • PLC Tutorials
  • Control Systems
Search
  • Courses
  • Videos
  • Q & A
    • Interview
    • MCQ
  • EE
    • Electronics
    • Electrical
  • Measure
    • Control Valves
    • Calibration
    • Temperature
    • Pressure
    • Flow
    • Level
    • Analyzers
    • Switches
    • Vibration
    • Solenoid Valve
  • Control
    • PLC Tutorials
    • Control Systems
    • Safety Instrumented System (SIS)
    • Communication
    • Fire & Gas System
  • More
    • Design
    • Tools
    • Animation
    • Basics
    • Formulas
    • Standards
    • TextBooks
    • Common
    • Software
    • Excel Tools
    • Erection & Commissioning
    • Process Fundamentals
    • Videos
    • Books
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Practical Questions > Calculate Hydraulic System Fluid Pressure

Calculate Hydraulic System Fluid Pressure

Last updated: June 2, 2020 6:22 pm
Editorial Staff
Practical Questions
No Comments
Share
6 Min Read
SHARE

In this hydraulic system, a force of 25 pounds is applied to the small piston (area = 10 in2 ). How much force will be generated at the large piston (area = 40 in2 )?

Contents
Hydraulic System Fluid PressureHydraulic Cylinder Question 1Hydraulic Cylinder Question 2Hydraulic Cylinder Question 3Hydraulic Cylinder Question 4

Also, calculate the fluid’s pressure.

Hydraulic System Fluid Pressure

Calculate Hydraulic System Fluid Pressure

Finally, explain how Pascal’s Principle relates to this scenario.

Answer:

Force at large piston = 100 pounds. Fluid pressure = 2.5 PSI.

Pascal’s principle states that any pressure applied to a contained fluid will be experienced at all points throughout that fluid. Thus, pressure generated by the 25 lb of force on the small piston creates a pressure (2.5 PSI) distributed throughout the fluid’s volume which is experienced in full at the large piston to create the 100 lb force there.

The 5 inch dimension is extraneous information, included for the purpose of challenging students to identify whether or not information is relevant to solving a particular problem.

More Questions:

1. Identify which fundamental principles of science, technology, and/or math apply to each step of your solution to this problem. In other words, be prepared to explain the reason(s) “why” for every step of your solution, rather than merely describing those steps.

2. Identify a practical application for a hydraulic system such as this.

3. Does the pressure/force/area equation hold true for all piston positions, or only with the pistons in mid-stroke as shown in the illustration?

4. Would it matter whether the fluid in this system was a liquid or a gas? Explain in detail how the system’s behavior would differ (or not differ) depending on the type of fluid used.

5. This mechanism seems to multiply the applied force. How can it do so without violating the Law of Energy Conservation (energy out cannot exceed energy in)?

6. Demonstrate how to estimate numerical answers for this problem without using a calculator.

Hydraulic Cylinder Question 1

If force is exerted on the piston of this hydraulic cylinder, in what direction(s) will this force be transmitted to the cylinder walls? In other words, how does a fluid under pressure push against its surrounding container?

Force exerted on hydraulic cylinder

Answer:

The fluid pressure will exert an outward force on the cylinder walls, like this:

Hydraulic cylinder walls Fluid pressure

Hydraulic Cylinder Question 2

Suppose a small rubber ball is floating inside the fluid of a hydraulic cylinder as shown below. What will happen to the ball when a pushing force is exerted on the cylinder’s rod? What will happen to the ball when a pulling force is exerted on the rod?

Answer:

pushing force on hydraulic rod

A pushing force on the rod will compress the rubber ball to a smaller diameter. A pulling force will expand it to a larger diameter.

Hydraulic Cylinder Question 3

A free-floating piston inside a hydraulic cylinder has a 1000 PSI of fluid pressure applied to one side of the piston, and 850 PSI of pressure applied to the other side of the piston. The piston itself is 2.75 inches in diameter. How much force will act on the piston, with these pressures applied to it?

free-floating piston inside a hydraulic cylinder

Answer:

Net piston force = 890.936 pounds.

In this scenario, there are two pressures fighting against each other: the 850 PSI pressure is pressing downward on the piston while the 1000 PSI pressure is pressing upward. The resultant (differential) pressure is 150 PSI (1000 PSI – 850 PSI). This is the pressure figure to be used in the final force calculation.

Hydraulic Cylinder Question 4

A double-acting hydraulic cylinder has 500 PSI of pressure applied to the side without the rod and 750 PSI of pressure applied to the rod-side. Calculate the resultant force generated at the piston and transmitted through to the rod, and also determine this force’s direction. The piston is 5 inches in diameter, and the rod is 1 inch in diameter.

double-acting hydraulic cylinder

Answer:

Net force = 4,319.69 pounds, in the downward direction.

If your calculated force turned out to be 4,908.7 pounds, you made a very common error. Once you have figured out what this error is, go back and try to see how the scenario would have to be altered in order to actually generate 4,908.7 pounds of force with the two pressures being 750 PSI and 500 PSI, respectively.

Read Next:

  • Live Zero in 4-20 mA Loop
  • Why we Tune a PID Controller?
  • 4-20 mA Formula
  • Compare Fieldbus & 4-20 mA
  • Control Loop Testing
Credits: Tony R. Kuphaldt
Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address
You've successfully subscribed !

Continue Reading

Identify High Flow Alarm and Low Flow Alarm?
Steam Eductor Question
Simple High Level Indicator Circuit
Troubleshooting PLC Permissive Inputs
How a Bourdon Tube Pressure Gauge might be Adjusted for Linearity?
Draw the appropriate Pressure Switch Symbol ?
Share This Article
Facebook Whatsapp Whatsapp LinkedIn Copy Link
Share
Leave a Comment

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Stay Connected

128.3kFollowersLike
69.1kFollowersFollow
208kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

LRV and URV of PT for Extreme Limits of Empty and Full
Liquid Level Measurement using Pressure Transmitter Questions
Paint Mixing System
How Nuclear Radiation is used to Measure Coke Dust Level?
Loop Powered Pressure Transmitter
Displacer Level Transmitter Questions
Process Control Loop Testing
Upgrading the Electrical System in an Automobile

Keep Learning

Span of Pressure Gauge

How to Decrease Span of Pressure Gauge?

Level Loop Troubleshooting

Identify Faults in PID Control Loop

Siemens PLC Questions

Programmable Logic Controller (PLC) Questions and Answers – 11

Pneumatic Transmitter

Pneumatic Level Transmitter Calibration Table

Programmable Logic Controller (PLC) Questions and Answers

Programmable Logic Controller (PLC) Questions and Answers – 1

Ladder Diagram circuit

PLC Practice Questions

PLC Motor Control Circuit

Motor Trip Logic using PLC Programming

Strain Gauge Bridge Circuit

Something is Wrong with Strain Gauge Bridge Circuit

Learn More

Calibration & Preventative Maintenance Procedures

Calibration and Preventative Maintenance Procedures

PLC Ladder Diagram program

Contacts and Coils in PLC Ladder Logic

Ladder Diagram circuit

PLC Practice Questions

Capacitor Bank

Poor Power Factor Boosted – Industrial Electrical Problems

PLC Programming Basics for a Packing Machine Control System

PLC Packing Machine Control System Program in XG5000

Ultrasonic Sensors Objective Questions

Ultrasonic Sensors Objective Questions

Common Control Valve Problems

Troubleshooting Common Control Valve Problems

PLC analog input scaling

PLC Analog Input Scaling

Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Welcome Back!

Sign in to your account

Username or Email Address
Password

Lost your password?