I've modelled a section of pipe as a 3d solid extrusion. It is a 20m long section and hence I want to vary the mesh density along the length of the pipe (z axis). I've tried partitioning the pipe section using datum planes (x-y) at various points along the length as well as a partition along the...
Can anyone provide me any guidance on using an ASTM A694 F52 forging in a design to ASME VIII. I can find to mention of ASTM A694 in ASME II (materials). Thanks
When analyzing pipeline stability using morisons equations, the stability generally decreases as the wave period is increased. Is this due to to a longer period carrying a larger volume of water and hence generating a larger force on the pipeline? As I would assume that a lower period would also...
The majority of my experience is related to subsea pipelines so excuse me if this question is obvious. Now for a pipeline if I want to consider the effective force I generally have two options, the fully restrained force (made up of end cap, thermal and poisson effect forces) or if I am looking...
Could someone direct me to some literature that will describe how to determine the minimum number of elements that should be used through a wall thickness for different element types? Thanks
I am aware that an API 17D 17SV swivel ring flange will generally have a lower bending moment capacity than the equivqalent API 6A 6BX (or API 17D 17SS) weldneck flange. In the past I have used API 6AF for a guidance on the capacity of a flange, however since this is only applicable for...
I was told today that when trying to provide cathodic protection to a riser within a j-tube it cannot be done with sacrifical anodes. Can anyone confirm this and give me some background as to why? I was told in a 'matter of fact' way and when I enquired further I wasnt given much of an...
I've been asked to confirm the wall thickness of some inconel high pressure tubing to b31.3. This is high pressure tubing, design pressure 600 bar. This results in a test pressure of 900 bar. The selected wall thickness is acceptable as per section 304, and specifically equation 3a. This is...
Could anyone provide any guidance on any material compatibility issues with specifying A453 Grd660 fasteners for use in a marine environment on Inconel Alloy fittings? I have checked the coefficients of expansion and there isn't a major difference so I wouldn't of thought this would/could lead...
I'm looking to find a weighted coating system applicable for a 2inch spoolpiece approximately 50m long. I've looked into concrete coatings however these are generally only applicable to 4inch+ from what i've read. I'm sure there must be a wrap/half shell system that can be used on spools but...
I know that over a pipeline the effective axial force is compressive (negative), and that it builds up to a constant value over the so called 'anchor length'. The 'anchor point' being the point at which the effective axial force in the pipeline equals the friction between the pipeline and the...
Can anyone guide me to an allowable hoop stress value for the hydrotest case for subsea piping to ASME B31.8 (Offshore Code?).
I have read through the code and can see no clear definitions. In offshore code (VIII) A847.2 makes reference to at least 1.25 times the maximum allowable operating...
I am currently designing an end cap (domed end) using PD5500. I cannot find any reference to SIFs in this code, or in the explanatory code for Section 3.5.2 (PD6550). If I have a step change in wall thickness from the pipe to the end pipe is there a SIF to be applied? Could someone please refer...
I am designing a component of a robot for the university I used to go to, I havent had experience of this type of mechanical design before (pipelines by trade). It is basically just a housing for a motor and pump- a few plates and a cylinderical housing etc. Are there any basic mechanical...
I am remodelling a subsea tie-in spool analysis performed by another company. The original design was performed in Autopipe and I am using Caesar. The original values for soil vertical stiffness were as follows, and input into Autopipe:
K1 = 0.02 N/mm/mm
K2= 0.014 N/mm/mm
Fy = 5000 N/m
In...
I am remodelling a subsea tie-in spool analysis performed by another company. The original design was performed in Autopipe and I am using Caesar. The original values for soil vertical stiffness were as follows, and input into Autopipe:
K1 = 0.02 N/mm/mm
K2= 0.014 N/mm/mm
Fy = 5000 N/m
In...
I need to purchase several thermocouples for a proof loading test I will be performing in the near future, this is not anything I have had experience of in the past and was looking for advice as to what type would be best suited. I will be testing a motor and monitoring the temperature during...
I am currently designing some anodes for cathodic protection of flexible pipe. I am trying to calculate the mean current requirement and I have the current density and the surface area however I am struggling to find the coating breakdown factors for the end fittings. They are coated in a Nickel...
On a recent project we said to the client that we plan to trench an umbilical but leave it to naturally backfill, i have been asked to confirm that the wave and current data supports the natural backfill. has this been addressed in any standards? or does anyone know of any papers written...
Could anyone please explain exactly what these are? I believe it is something to do with extra length for welding and it tends to have been approx 500mm whenever I've come across it however I am not 100% sure exactly what they are. Thanks. jt
