That's what is specified in ASME 31.3, 2004 para 302.2.4 (1) (a).
For internal pressure piping systems are designed to ASME 31 series codes and not to ASME PV codes.
Christopher Wright <chrisw@skypoint.com> wrote:
On Sep 7, 2005, at 5:19 AM, Venkat hariharan wrote:
> What if an existing piping is rerated to a higher pressure and the
> available pipe thickness just satisfies the new operating pressure,
> Is the 1.5xtimes test pressure is mandatory in this case? Can the
> piping withstand the new test pressure? Operating temprerature is
> around 350 deg F. Code allows only upto 33% overpressure for less than
> 10 hrs at any one time.
How certain are you about this? Again, referring to the ASME PV Codes,
no such over-pressure is permitted under any circumstances of service.
Commonly-held mis-information is that a 10% over-pressure is permitted,
but that's an incorrect interpretation of the rules for safety relief
valves, which state that the internal pressure may rise 10% only while
the relief device is opening fully.
Christopher Wright P.E. |"They couldn't hit an elephant at
<a href="/group/PipingDesign/post?postID=yaIp3HE8FtY4GxwOxUQVLD8aKvbTiLYxnoNvO6gn21D1IFBXS1yIncocabzNh08zISOVotEVhQAT_Sqfiw">chrisw@skypoint.com</a> | this distance" (last words of Gen.
.......................................| John Sedgwick, Spotsylvania1864)
To unsubscribe from this group, send an email to: <a href="/group/PipingDesign/post?postID=eNDhaShRWsra-FNvEAgLxkVp2MgDcSM3qYsCwjbuGvACw3uwKim4CKwenQ7-aFjh9RSpx94G0i2fuEPplD6XhOBzpQUwF_nnBwPj1B8G_JWC7Q">PipingDesign-unsubscribe@yahoogroups.com</a>
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed] Received on Sat Sep 10 06:16:00 2005
This archive was generated by hypermail 2.1.8 : Tue Mar 04 2008 - 11:40:44 EST