There is also a useful advisory centre (basically a kind of trade association for pigging companies) which you can use a starting point. There web address is www.piggingassnppsa.com.
Your point is noted. However, considering that I am looking at very low pressure pipelines (operating at 5 bars or so) with a CO2 content of 2%, I get a CO2 partial pressure of 0.1 bar. As I mentioned in my original post, I remember of a project where it was stated that below a certain threshold...
Just to confuse things a bit. I have been involved in a project where the Design Pressure was slightly higher than the MAWP (by 10%). The origins of that was that the relief valves were set at 100% MAWP and hence the Design Pressure was set at the 100% value. The hydrotest pressure was then...
I am looking at a wet gas pipeline with a small quantitiy of C02 in the gas composition (1 to 2 % mol). The pipeline pressure is in the rage of 5 to 10 bars.
I think I remember, from a long time ago, about a rule of thumb which states that, below a certain value of partial pressure of CO2, the...
I am looking at a wet gas pipeline with a small quantitiy of C02 in the gas composition (1 to 2 % mol). The pipeline pressure is in the rage of 5 to 10 bars.
I think I remember, from a long time ago, about a rule of thumb which states that, below a certain value of partial pressure of CO2, the...
Just a thought. The cantilever formula is based on the assumption that the end is fully built in (i.e no rotation at the end). If the end has any kind of flexibity, then the deflections will be higher than those calculated from a cantilever formula. In your example, I estimate that a 2deg...
Sorry, my post was not clear enough. D is the diameter of each of the 3 tubes (1"). The term D*(1+1/Cos(30)) represents the diameter of the envelope circle. I note that the number is the same as that derived by prex.
Line pipe (or even linepipe) is used very commonly in the context of pipelines. As far as I am aware, the definition of this term is as described by joshikv (Kaustubh). Lined pipe is a different issue and API 5L does not deal with that.
Generally, linepipe is also used to refer to the steel pipe joints (tyipcally 12m long) you buy from the mills and subsequently weld together to build the pipeline. See for example the title of API 5L.
As you mention, these are all terms uite loosely in certain working environments
Maybe I am thinking along the wrong lines competely, but from my school days, I remember that we used to put in strain gauges in pairs at 90deg relatively to each other, primarily to eliminate the error due to mis-alingment. As strain gauges measure only linear strains, the shear strain was...
I would not under-estimate the external pressure in 900m of water depth. You may find that the governing criteria for the wall thickness is indeed the pipeline collapse. For the buckle arrestors, you will need even thicker pipe depending on the length of the buckle arrestor and the main line...
For pipe collapse checks, look at
* BS 8010, Pt 3, Annex C
* Timoshenko and Gere, Theory of elastic stability (Book)
* Murphy and Langer, Ultimate pipe strength under bending (technical paper, maybe OTC)
* DNV 1996 and DNV 2000
These are not in any particular order other than as I found them...
200 deg C and HDPE do not seem to go together very well. I do not have my HDPE catalogs handy but from memory, you cannot use them in temperature above 60-75 deg C. Even then, you have start derating the material (above 20 deg C). Also creep efects become significant above this temperature.
All...
I had a similar problem and, for me it was for the reasons that "jackzhong" stated above. If you notice, the constants in the polynomials change sign, C6 is -ve, C5 is positive, etc. As a result, you end up having subtraction of two large number to obtain a relatively small number...
Does anybody out there have any experience with pigging of low pressure pipelines. We have a problem in that the pipeline operates at very low pressures (2 to 4 bars). The concern is that these pressures might not be high enough to drive the pigs through the pipeline. From memory, I remember...
