RE: Jacketing

From: <Christopher>
Date: Thu Oct 18 2001 - 10:07:00 EDT

>Spacers are installed on the OD of the inner cylinder to maintain the gap of
>the annulus.

Section VIII design requires that stiffening rings, if needed, have to be substantially circumferential although some gaps are allowed. The pipe may buckle like you've described if it isn't stiffened curcumferentially at definite intervals.

>I suggest that Thickness has
>to be checked both for external and internal pressure.
Absolutely right if it's intended to carry higher pressure in the jacket than in the inner chamber for normal service.

>How do we hydro a double pipe ? Separately?
Depends on how the system works in service. You really have to simulate the actual working pressure distribution. If this were a shop test you'd blank off both ends as they would be in service and pressurize each chamber independently through the working connections.

Christopher Wright P.E. |"They couldn't hit an elephant from <a href="/group/PipingDesign/post?postID=RnIByyUqUypFqaOl8eEvO_aWGIvjiN4l5ExLNmWejQI2K_fpSPhugnWAU1GkmhviGOKHkwI2kV3MnA">chrisw@skypoint.com</a> | this distance" (last words of Gen.

___________________________| John Sedgwick, Spotsylvania 1864)

<a href="http://www.skypoint.com/~chrisw">http://www.skypoint.com/~chrisw</a> Received on Thu Oct 18 10:07:00 2001