DESIGN PRESSURE FOR PIPING CLASS
DESIGN PRESSURE FOR PIPING CLASS
(OP)
Hi every body.
I would like to know if for the elaboration of a piping class for a main station where the working pressure is about 60 psig I should design using the maximum pressure in the system or I should use the maximum pressure of the flange ( 275 psig to 200 ºF). And if the last is true where can I get that information.
I would like to know if for the elaboration of a piping class for a main station where the working pressure is about 60 psig I should design using the maximum pressure in the system or I should use the maximum pressure of the flange ( 275 psig to 200 ºF). And if the last is true where can I get that information.





RE: DESIGN PRESSURE FOR PIPING CLASS
RE: DESIGN PRESSURE FOR PIPING CLASS
I'd say design for what you need. If you need 60 psi and the fluid is not corrosive, then plug 60 psi in the design and add a small value for corrosion (round up to nearest standard). As for flanges, you can not get standard flanges les than 150 ANSI (they do have a 125 ANSI flat face, but mostly for water service).
The reason some engineers go ahead and make the pipe match the flange ratings is because "internal standards" say so, no more no less. The internal standards are usually set to minimize design work and make sure there are fewer errors during install. I had an engineering firm tell me they had to use SCH 80 4" on a skid because SCH 40 was not rated to the ANSI 600 flange (1480 psi)and that met their "internal standards". All the vessels and relief valves were rated at 1000 psig. Now what did the engineering firm save me by making the piping good to2270 psig?
You get to set your "internal standards". So have some fun, be an engineer.
RE: DESIGN PRESSURE FOR PIPING CLASS
EJL
RE: DESIGN PRESSURE FOR PIPING CLASS
One step is often forgotten in engineering.
When you have checked or designed what you actually need, you also have to check for cost and time against what is actually commercially readily and cheapest available!
Typical example is the 150LB flanges mentioned above, probably cheaper than 125LBS. What about piping size and material?
RE: DESIGN PRESSURE FOR PIPING CLASS
RE: DESIGN PRESSURE FOR PIPING CLASS
http://virtualpipeline.spaces.msn.com
RE: DESIGN PRESSURE FOR PIPING CLASS
RE: DESIGN PRESSURE FOR PIPING CLASS
Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng
www.waterhammer.bigblog.com.au