Pipelines are typically constructed using a combination of “roping” (grading the right of way to reduce the number of required factory and field bends) and “bending” (using field bends to accommodate undulations discovered along the right of way during construction).
Roping analysis can be...
I’m curious if anyone here has ever completed an Engineering Assessment (EA) to support a non-conformance to a code requirement during new construction. This is primarily a philosophical question since CSA Z662-15 is unclear regarding whether or not an EA can be adopted at the construction...
When calculating longitudinal compressive stress for restrained portions of pipelines, CSA Z662 references the commonly used formula:
SL = v*SH – E*alpha*(T2-T1)
Where,
SL = longitudinal compression stress
SH = hoop stress due to internal design pressure
v = Poisson’s ratio
T2 = maximum...
In Canada, we typically follow TC E-10 guidelines when crossing a railways with our pipelines. These guidelines require that, “pipelines shall be installed under tracks by boring and/or jacking, if practicable”.
I have always interpreted this to require that “auger boring” or “pipe hammering”...
Anyone know of a good slip-sleeve pipe wrap? Looking for two independent overlapping layers of geosynthetic material that we can use where we identify moderate risk of ground movement due to slope instability. This would be for cases where our pipeline is running parallel (i.e. in-line) with...
My question is: Does removing a coupon from a test bend relieve the residual stress in that coupon? Or can I remove a small coupon from the test bend and still accurately measure the residual stress introduced into the steel during the cold bending process?
Overview:
I am currently exploring...
Anybody think a NPS 4 x 4.0mmWT CL600 RFWN flange would hold at 22,337.8 kPa? Think the gasket would blow out before bending the flange?
Background:
Assume the Cold Working Pressure of a CL600 flange is 9,930 kPa (which it is in the CSA Z245.12 flange standard).
Therefore, 1.5 x CWP = 1.5 x...
Anybody ever heard of compelling argument to use X65 (Gr. 448) over X70 (Gr. 483) line pipe for sweet service, sales oil, transmission pipelines? NPS 20 for discussion purposes.
Thanks in advance for any input.
Anybody every build a NPS 20, Gr. 448 x 12.7mmWT cold bend (25D bend radius x 30 degrees). ERW line pipe. Internal mandrel is available. Satisfying the requirements of CSA Z245.11-14 (not too sure if ASME has a cold bend standard equivalent to ASME B16.49 for induction bends). Shop...
CSA Z662-15 Clause 10.10.8.3 provides equations for evaluating small buckles, ripples, wrinkles. It requires that the user input the crest-to-trough height and the “maximum operating stress”.
Should the “maximum operating stress” used to evaluate a buckle be:
a) Hoop Stress
b) Longitudinal...
Background:
EPRG and National Grid Transco (formerly British Gas) recommend pressure reduction to at least 85% of that at the time of the damage. When visual examination during excavation reveals the damage to be more than superficial or when ILI results categorize the damage as severe or...
Have a look at the attached (Heat-Traced Pipelines – A Double-Containment Solution for a High-Temperature Pipeline). This is an article from the 2014 IPC event in Calgary. I kept it because at the time I was very interested in alternative design solutions for hot bitumen pipelines.
I dug it...
Reference:
L C Peng’s “Pipe Stress Engineering” book, Chapter 10 (Transportation Pipeline and Buried Piping), Section 10.2.3 (Potential Movement of Free Ends).
Equation 10.16:
L = F/f
Where,
L = virtual anchor length or active length
F = The anchor force
f = the longitudinal friction force...
Does anyone have a reference for tables or formulas that detail the relationship between compressibility of water (or bulk modulus) vs. Pressure and Temperature?
i.e. at T = 0 deg C, P = 20,000 kPag is the bulk modulus of water significantly different than at T = 20 deg C, P = 0 kPag (bulk mod...
Just reviewing a great paper published by LC Peng that presents basic calculations for the stress analysis of underground pipelines. I’m sure most of you are familiar with this paper but here’s the link anyways:
http://www.pipestress.com/papers/UnderGrd-1.pdf
Page 4 of 5 works through an...
Can anyone recommend a good Pipeline Engineering textbook for calculating stress in fully restrained, below ground pipelines?
My background is in pipeline construction but I’m very interested in pipeline design as well. I’ve read a few papers authored by L.C. Peng that introduce the idea of...
Is there any way to de-rate the MDMT of A105 material used for flanges or valve bodies in B31.3 piping systems? B16.5 and B16.34 both restrict A105 to -29 deg C in their respective Pressure-Temperature charts and B31.3 Table A-1 also limits the min. temp. to -29C.
I am aware that for some...
CSA Z245.12 (Steel Flanges) Table 1 (p. 14 in 2009 edition) provides maximum cold working-pressure ratings for various nominal pressure classes (PN 20 to PN 420). These cold working pressure ratings are for temperatures lower than or equal to 120 deg C.
Table B.1 (p. 39 in 2009 edition)...
B31.3 Paragraph 302.3.2 (a) states for bolting materials that: Design stress values at temperature for bolting materials shall not exceed the lowest of the following:
(1) One-fourth of specified minimum tensile strength at temperature.
(2) Two-thirds of yield strength at temperature.
(See...
I am currently designing a line blank component using SA-564 Type 630 (a 17-4 PH stainless steel) in the H1150M age hardened condition. However, ASME Section II, Part D, Table 1A only lists maximum allowable stress values (S) for SA-564 Type 630 in the H1150 age hardened condition. No allowable...
