Compressed Air n' Pressure Question

Click For Summary
SUMMARY

The discussion focuses on the properties of compressed air in a tank and the behavior of air when released through a valve. A specific calculation for determining the flow coefficient (Cv) of gas passing through a control valve is provided, using the formula: CvValve = (LbsGasHr / (3 * SQR(PsigInAdj * PsigOutAbsol)). The discussion also highlights the adjustment factors for PsigInAdj based on pressure levels, specifically using 80% for pressures of 15 psig or less and 43% for pressures over 15 psig. A resource link to Engineering Toolbox is shared for further calculations and insights.

PREREQUISITES
  • Understanding of fluid dynamics principles
  • Familiarity with control valve flow coefficients (Cv)
  • Basic knowledge of pressure measurement units (psig)
  • Ability to perform mathematical calculations involving square roots and algebraic rearrangements
NEXT STEPS
  • Research the properties of compressed air and its thermodynamic behavior
  • Learn about control valve sizing and selection techniques
  • Explore the use of the Engineering Toolbox for various engineering calculations
  • Study the effects of pressure drop on gas flow rates through valves
USEFUL FOR

Engineers, technicians, and anyone involved in fluid dynamics, particularly those working with compressed air systems and control valves.

dingpud
Messages
198
Reaction score
1
Does anyone know of an internet site that discusses the properties of compressed air in a tank, and how the air behaves when it is released from the tank. Also, is there an equation which describes the rate at which air leaves through a valve of a tank?

Thanks much
 
Physics news on Phys.org
Here is a calculation to determine the Cv for gas passing a control valve:

CvValve = (LbsGasHr / (3 * SQR(PsigInAdj * PsigOutAbsol))

PsigInAdj use 80% for 15 psig or less
PsigInAdj use 43% for over 15 psig

If you know the Cv of the valve but not the flow, you can rework this to solve for the lbs of gas per hr.

Here is a site that can give you just about all you need to perform the calculations:


http://www.engineeringtoolbox.com/22.html
 
Last edited by a moderator:
Ahhh Much clearer now.

This clears up a lot.

Thanks.

--------------------------------------------------
working to help protect our troops
 

Similar threads

Undergrad Compressed air Pushing a Column of Water
  • · Replies 11 ·
Replies
11
Views
4K
Undergrad How much time to pressure balance two air chambers
  • · Replies 4 ·
Replies
4
Views
2K
High School Rebound Height vs Air Pressure: A Puzzling Relationship
  • · Replies 10 ·
Replies
10
Views
4K
Undergrad Water pressure affects air pressure
  • · Replies 9 ·
Replies
9
Views
4K
Undergrad Filling a rigid tire from a pressure regulated compressed air line
  • · Replies 67 ·
3
Replies
67
Views
6K
High School Pressure of air inside a glass
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Velocity of compressed air through pipe
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad How pressure affects partial pressures (and dewpoint)
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Designing a compressed air vehicle
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad "Air Pressure" is not "the weight of the air above you"
  • · Replies 27 ·
Replies
27
Views
5K