Allowable forces & moments

As per our company standards , Allowables for 6" pipe with 160 Sch are ,

FX,FY,FZ:13060 N MX,MY,MZ:3968 N-M .

But the resuls i got are ,
FX:315 N FY:4024 N FZ: 3669 N MX:5340 N-M MY:545 N-M MZ: 0 N-M .

Here forces are below the allowables , but only MX is above allowables where as MY , MZ are nominal , so can i consider the resultant of forces & moments to be below allowables .

Please guide me in this issue . MX cant be decreased by changing the support locations nor by possible change in routing.

You need to submit your loads with the resultants to your Mechanical / Equipment group for approval. The allowables you quote are probably based only on company policy.

Have you read API610 annex F as an example? For some mathematical basis your output may still comply! And Moverz is right... try to scan the company file and study on how it is derived because in loading allowables each component forces or moments are dependent to each vector. BUT! Consult your SV first before doing such case or those who make justification of your standards.

Regards!

Hello Naveen,

Perhaps you can make WRC107/297 run to find the local stresses(i.e if you find it ok you can send it to your equipment group without any hesitation).
This will require some basic knowledge regarding pressure vessels and local stresses.

Or else a simpler thing is that nozzle flexibility can be utilized by opting for the WRC nozzle which will reduce the piping imposed loads.

With Regards

Vignesh.

Are you sure you can't decrease your loads? Guide support can also be the issue there. Have you tried to adjust their gaps?

There is no such thing as a moment load that can't be reduced by a reroute. If in-plane changes have no effect, try out-of-plane ones!