Vacuum pressure and absolute pressure - thermodynamics, Mechanical Engineering

Vacuum (Or Vacuum pressure) (Pvacc):

It is pressure of fluid, which is always less than atmospheric pressure. Pressure in a steam condenser is one such example. It can be measured by a pressure gauge but the gauge reads on negative side of atmospheric pressure on dial. The vacuum signifies difference between absolute pressure and atmospheric pressures.

Absolute Pressure (P abs):

It is pressure of fluid, which is measured with respect to the absolute zero pressure as the reference.

Absolute zero pressure can occur only if molecular momentum is zero, and this condition occurs when there is perfect vacuum. Absolute pressure of fluid can be more or less than atmospheric depending upon, whether gauge pressure is expressed as absolute pressure or vacuum pressure.

Inter relation between various types of pressure representations. It is shown in Figure given, which can be expressed as follows.

pabs = patm  + pgauge

pabs = patm  - pvace

330_Vacuum pressure and absolute pressure.png

Posted Date: 10/15/2012 1:18:55 AM | Location : United States







Related Discussions:- Vacuum pressure and absolute pressure - thermodynamics, Assignment Help, Ask Question on Vacuum pressure and absolute pressure - thermodynamics, Get Answer, Expert's Help, Vacuum pressure and absolute pressure - thermodynamics Discussions

Write discussion on Vacuum pressure and absolute pressure - thermodynamics
Your posts are moderated
Related Questions
What is the chief advantage of CIDR over the original classful addressing scheme? CIDR stands for Classless Inter-Domain Routing is a new addressing scheme for the Internet, th

defect of casting

An airfoil of surface area 1.5 ft2 is tested for lift L in a wind tunnel. At an angle of attack of 7° with standard air of density 0.0024 slugs/ft3 at a speed of 90 ft/sec, the lif

Objective type/ short-answer type questions. Describe the following :- a. Illustrate what do you mean by CAD/ CAM b. Discuss the storage device used in computer. c. Wha

Q. Which functions used for coating? • Improves arc stability by providing certain chemical which have this ability, by ionizing the path of arc. • Provides a protective gaseou

Define Essentials of Milling Fixture? Strength of withstand heavy forces. Thrust should be directed towards a strong, solid structure. Cutter setting piece should b

FRICTION: you have learnt laws of friction and problems involving dry friction. The relative sliding motion of one body on another body is resisted by forces called as frictio

Q.   Derive the expression of torque developed in closely excited magnetic system. Clearly explain then assumption made.   Sol. Double - Excited System   A doubly - ex

Q. Describe Elastic and plastic deformation? When a sufficient load is applied to a metal or other structural material, it will cause the material to change shape. This chang

#A spherical aluminum vessel has an inside diameter of 30 cm and contains water at 80 ?C, with a quality of 1%. The vessel is then heated until the water inside is saturated vapor.