Design Pressure vs. MAWP

Quiet lately...

Art Montemayor has a nice write-up here:

<a href="http://www.cheresources.com/chexpress/chexpress07_18.shtml#technically">http://www.cheresources.com/chexpress/chexpress07_18.shtml#technically</a>

An excerpt:

<<What is the difference between "Design Pressure" and "Maximum Allowable Working Pressure" (MAWP)?

It is not unusual for engineers to get confused with the terms "design pressure" and "Maximum Allowable Working Pressure" (MAWP). The two terms are not related mathematically; rather, they are related in a practical procedure that takes place during the actual fabrication of a pressure vessel.

Every Chemical Engineer - sooner or later - will have to deal with a pressure vessel fabrication or operation and it is sound and good advice that he/she should familiarize themselves with engineering terms employed and the logic of their application. In dealing with or specifying a pressure vessel, an engineer must resort to filling in or using a Vessel Specification Sheet that you should be familiar with and employ in the course of your work.

The "Design" pressure is that pressure that the engineer decides is the value of the pressure at which the vessel will normally operate (or which it must withstand under operating conditions). This value must include any normal excess pressure that can occur during the vessel's operation. This is a discretionary value that depends on the background and experience of the design engineer. Sometimes the design value can be 10% over the pressure calculated (as in a simulation) or as much as 25% more. Good engineering judgment is employed in arriving at this design figure.>>

See the link above for the rest. Received on Thu Sep 06 21:25:00 2007