Pipeline design pressure for ASME B31.8 pipe
Pipeline design pressure for ASME B31.8 pipe
(OP)
Hi there.
I Have a problem.. If one wanna design the topside piping design based on B31.3, we have to look the pressure and temperature rating based on ASME B16.5 to check the MAWP for the specific design temperature for the specific material.
But, if I want to design gas pipeline, which using B31.8 code, does anybody know what is the design guideline in determining the MAWP with respect to the design temperature of the certain material. Somebody told me to use MSS standard, of which I wouldn't know exact MSS number for such application.
Need help from you.
Thanks
Rusman Abu Samah
Process
I Have a problem.. If one wanna design the topside piping design based on B31.3, we have to look the pressure and temperature rating based on ASME B16.5 to check the MAWP for the specific design temperature for the specific material.
But, if I want to design gas pipeline, which using B31.8 code, does anybody know what is the design guideline in determining the MAWP with respect to the design temperature of the certain material. Somebody told me to use MSS standard, of which I wouldn't know exact MSS number for such application.
Need help from you.
Thanks
Rusman Abu Samah
Process
RE: Pipeline design pressure for ASME B31.8 pipe
For B31.3, required thickness of the piping is calculated using the formulas and material strengths within B31.3. However, for the flanged components, you are directed to B16.5 and for the vast majority of cases, these are the limiting components and therefore set the pressure/temperature limits for the system.
I 'thought' B31.8 had similar formulas for the strength of the piping but again, for the flanged components, you are constrained by B16.5.
RE: Pipeline design pressure for ASME B31.8 pipe
RE: Pipeline design pressure for ASME B31.8 pipe
However, it doesn't directly set the flange pressure/temperature ratings, those are handled by B16.5 so from your point of view, you wind up with the same flange rating but thinner pipe.
RE: Pipeline design pressure for ASME B31.8 pipe
RE: Pipeline design pressure for ASME B31.8 pipe
The design formulae in B31.8 describe the procedure to
determine the required wall thinckness. YOur first step is knowing your design P & T. Once those are known it becomes a trial-and-error process to select the wall thickness based on your material requirement. Start with, say, X-52 as your first selection. You get the allowable stress for X-52 from the stress tables located in the back of B31.8 based on your operating pressure. Note that the allowable stress goes down as the operating pressure increases. I assume you already have a diameter selected based on your pressure and delivery requirements. So you calculate a t for X-52, then you check cost and availability for that pipe size and wall t, if too expensive, or bad dleivery, try a different material like X-60. Trial and error. Hope this helps!
Thanks!
Pete
P. J. (Pete) Chandler, PE
Mechanical, Piping, Thermal, Hydraulics
Processes Unlimited International, Inc.
Bakersfield, California USA
pjchandl@prou.com
RE: Pipeline design pressure for ASME B31.8 pipe
Thanks
Rusman
Senior Process Engineer
RE: Pipeline design pressure for ASME B31.8 pipe
B31.8 is where you need to be looking for your flange requirement. There will be something in there about fittings requirements. That is the place to start.
Also - I made a boo-boo in my earlier post when I said that "You get the allowable stress for X-52 from the stress tables located in the back of B31.8 based on your operating pressure"; I should have said that the allowables are a function of temperature.
Thanks!
Pete
P. J. (Pete) Chandler, PE
Mechanical, Piping, Thermal, Hydraulics
Processes Unlimited International, Inc.
Bakersfield, California USA
pjchandl@prou.com