MoverZ is right as pump bearings and couplings are more liable to failure when anchors are placed close to nozzle than if you have a flexible piping connections at nozzle without anchors.
Always remember that bearings have millimeters of clearance and once piping moves; either the housing or the bearing get close to each other..they strike and start heating up. Alignment of such pumps also create problems and lots of re-work.
The way I see it is: do your calculations/stress models as per Standards imply which will in turn provide you to go for a "conservative approach". The only difference of application of all these norms and standards is: some may be too close or some may be too far from this conservative approach but both would be safe.
As your software/calculation gives u high axial force than reduce this axial force by doing whatever you can (remove anchors for instance). Your piping will be more flexible and nozzle loads will be much less [in reality] and your equipment/piping will have much longer life than predicted by the same Standard. Instead of risking the reputation of your company or decreasing the life of dynamic equipment in your project you should consider not placing them at nozzles.
Our Standards do say to consider all the dynamic & transient effects of fluids in the piping but mostly they are ignored in calculations. Once you put them in calculations you will see that providing anchors might solve one problem only but create many more.
If you really want to put anchors than place expansion joints or hangers in between them and nozzles.
Edited by salz64_QES (06/12/11 04:56 AM)
_________________________
Regards,
Salz
Pipe Stress Engineer,
Salzvision@gmail.com