I am relatively new in estimation o

[Roshanakm]

I am relatively new in estimation of strength of steel pipeline. I have been asked to estimate the strength of an 1800 mm storm water corrugated steel pipe, which has been corroded, and it is supposed to reline with Nuflow liner technology. I have attached Flexure Test and Compression Test of Nuflow technology to this message.
I would be thankful, if some one advice me in this regard.

http://files.engineering.com/getfil...497-4b41-85cb-3dce1a3278ca&file=Image0002.JPG

http://files.engineering.com/getfil...053-438f-a16c-c99241736647&file=Image0003.JPG

http://files.engineering.com/getfil...e39-4918-a6ff-b886a34807c6&file=Image0004.JPG

http://files.engineering.com/getfil...a08-43ef-bc36-d14cd7ce9688&file=Image0005.JPG

 

[Leonardobetta]

Your inquiry has conflict with your attachments; as you are requesting to calculate strength for steel pipelines and your enclosed attachments are indicating PVC material. In this sense, referring to your att. "PVC Material"; kindly find the below answer for your inquiry:


Collapse Strength of PVC Pipe:
The following is the ASTM F 480 formula for determining the collapse strength of PVC pipe manufactured in accordance with said standards.

Pc=(2E/(1-u^2))/(1/((Do/t)[Do/t-1]^2)


Where: Pc = Collapse pressure of PVC pipe (psi)
E = Young's Modulus for PVC (4x105)
u = Poisson's Ratio (0.33)
Do = Outside diameter of pipe (inches)
t = Wall thickness (inches)


Another formula used to determine the collapse strength of PVC is shown below. This formula, is more conservative than the ASTM formula. However, since most PVC materials are made to minimum allowable wall thickness rather than nominal sizes, it may provide a more accurate estimate of actual collapse strength.

Pc=((2E)*.75)/(1-u^2)[Do/t-1]^3


Physical properties of PVC vary with temperature. The values obtained with these formulas are consistent with a temperature of 70°F. As the temperature rises, PVC working strength decreases by approximately 0.5 psi per degree Fahrenheit above 70°F. Obviously, much care must be taken during cementing operations or in other high temperature environments.

 

[Roshanakm]

Hi Leonardobetta,
I have been asked to estimate strength of corroded steel pipe, which has been relined with nuflow material and attachments are technical information related to material which is used for reline. In fact steel pipes are relined with mentioned resins in attachments.
On the other hand, I should make a comparison between the strength of relined Steel pipe and Concrete Spun pipes (Humes Company product) type II, which normally is used for stormwater. If the strength of relined steel pipes are equal to concrete pipe, this method can be used for stormwater projects.
For estimation of strength of concrete pipe 1800 mm :
σ = MY/I
M= (Proof Load based on standard AS/NZS 4058) *(Length of pipe)2/ 2
Y=900 mm
I= π (d14-d24)/64

And ring stiffness= EI/D3
t= wall thickness of each layer
D= diameter to neutral surface of each layer
I= t3/12 for a unit slice of each layer
E = 28 GPa for concrete pipe
Am I on right track for concrete pipe?