Calculate pressure loss due to bends in a pipe?

Click For Summary
SUMMARY

The discussion focuses on calculating pressure loss in pipes due to bends, specifically addressing 90°, 60°, and 45° bends. The resistance coefficient for a 90° bend is defined by the formula K_B = (n-1)(.25*\pi f_T \frac{r}{d} + .5 K) + K, where K is derived from specific loss coefficients based on the radius-to-diameter ratio. To adapt this for other angles, the angle factor can be calculated using the equation y = 1.838E-7*A3 - 8.756E-5*A2 + 1.748E-2*A, where A is the angle of the bend. This method allows for accurate pressure loss calculations across various bend angles.

PREREQUISITES
  • Understanding of fluid dynamics principles
  • Familiarity with resistance coefficients in piping systems
  • Knowledge of friction factors in turbulent flow
  • Basic mathematical skills for curve fitting and polynomial equations
NEXT STEPS
  • Research the impact of bend angles on pressure loss in piping systems
  • Study the derivation and application of the angle factor equation for bends
  • Explore the Crane paper for detailed resistance values for various pipe bends
  • Learn about the effects of different friction factors on overall pipe performance
USEFUL FOR

Engineers, fluid mechanics professionals, and anyone involved in the design and analysis of piping systems will benefit from this discussion, particularly those focused on optimizing fluid flow and minimizing pressure losses in pipe bends.

daftdave11
Messages
11
Reaction score
0
how we doing i found the following information regarding finding the pressure drop in a pipe due to 90° bends. i was wondering could this be adapted for say a bend of 60° or 45°. what would be needed to change to the below information to allow this to happen?? thanking ou in advance. this would be a great help to me if i could find the solution to this.. thanks

K_B = (n-1)(.25*\pi f_T \frac{r}{d} + .5 K) + K
Where:
K_B = Resistance coefficient for overall pipe bend.
n = # of 90° bends (for a single 180° bend, n=2).
\pi = well...pi
f_T = Friction factor in turbulent zone.
r= radius of bend (in same units as d).
d= inside diameter of pipe (same unit as r).
K= Loss coefficient for a 90° bend based on table below.

90° Bend Loss Coefficients:
r/d = 1, K = 20f_T
r/d = 1.5, K = 14f_T
r/d = 2, K = 12f_T
r/d = 3, K = 12f_T
r/d = 4, K = 14f_T
r/d = 6, K = 17f_T
r/d = 8, K = 24f_T
r/d = 10, K = 30f_T
r/d = 12, K = 34f_T
r/d = 14, K = 38f_T
r/d = 16, K = 42f_T
r/d = 20, K = 50f_T
 
Engineering news on Phys.org
anyone??
 
daftdave11 said:
i was wondering could this be adapted for say a bend of 60° or 45°. what would be needed to change to the below information to allow this to happen?
You have the values given by the Crane paper for the total resistance of a 90 degree bend. You can multiply those resistance values by the following equation to get the resistance for all other bends between 0 and 180 degrees:
y = 1.838E-7*A3 - 8.756E-5*A2+1.748E-2*A
Where y = angle factor
A = angle of pipe bend from 0 to 180 degrees

This equation comes from a graph out of a book on fluid flow from a company I used to work for. I took the graph and did a curve fit to it. You should find that at 90 degrees the angle factor comes to 1.00 and at 180 degrees, the angle factor comes to 1.38.
 

Similar threads

  • · Replies 20 ·
Replies
20
Views
11K
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
Replies
4
Views
2K
Replies
13
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K