Does anyone know any suppliers of fully welded (as opposed to 3 piece or top entry) 900# large diameter (36" - 42") ball valves?
The application is main line valves on a natural gas pipeline (i.e. buried). I know Cameron offer them, but was looking for other possible vendors.
Does anyone have a reference for for an SIF on a taper (i.e. the taper for butt welding 2 different wall thickness pipes together)?
I am aware that the actual girth weld has an SIF of 1 in B31.3, but was wondering how much of an effect the taper has on stress intensification.
GregLamberson: You mentioned "The latest edition of B31.3 permits the same waiver of a hydrotest as 31.4 on “Tie-in” welds between two sections of piping that have been previously tested in accordance with the code."
I have been unable to find this in B31.3-2004. Could you give me a reference...
Metengr;
Not looking for a reason to decommission vessel, but wanting to ensure I have accounted for everything in my DBTT calculation. This reactor vessel has been operating for 30 years at temperatures up to 400-500°C and the client is concerned there may be a drift in transition temperature...
I am trying to determine an appropriate temperature margin to account for drift in the ductile-brittle-transition-temperature due to pressure vessel age.
I have used API RP 579 to determine the minimum allowable temperature for the vessel thicknesses / materials but want to add a margin to...
What I'm REALLY trying to figure out from this exercise is: Approximately how much kinetic energy must a boat transfer to the pipe to cause a pipe rupture?
My thinking was to apply a load to the pipe to displace it incrementally until it ruptures (not sure how I figure out where that point...
I would like your thoughts on how to model a ship impact on an over water pipeline. I want to determine the force and displacement required to rupture the pipe (i.e. the work). I was thinking of a non-linear analysis but am unsure of how to determine at what point a leak would begin. Any ideas?
By elastic-perfectly-plastic do you mean the stress strain curve would have astraight line up to the yield point and then a horizontal line from there on?
Wouldn't this be very conservative as the material will keep straining until the stress gets back below the yield stress?
Does anyone have a typical stress-strain curve for ASTM A53 Gr.B carbon steel pipe? If not, something similar?
I would like it for a non-linear FEA model.
I have a photo of a bonney forge weldolet with the following stamped on it;
6" x 12"
SCH100 (header) x SCH 160 (branch)
I gather this is just a standard SCH160 weldolet with a special stamp on it. What's the point of that? The weldolet won't change dimensionally for a SCH100 header will it...
If the branch and header are different schedules are the following weldolets ok;
Std WT header, XS branch - buy XS weldolet
XS header, Std WT branch - buy XS weldolet (will have step down to branch pipe WT). If step unacceptable for flow reasons, request weldolet bore be machined down to match...
