Pump Nozzle Loading

Hello everyone.
I am new to pipe stress analysis. I am having trouble reducing the load in the pump nozzle. My problem is that out of 3 axis, two axis have load below allowable limit and one axis has over. The combined is also below the allowable limit. Will this have any impact to the pump?

each component require different approach.
Exactly which one is causing you trouble?

Yes,
and can we see the configure?

If the pump is strictly an API style pump with API specified allowable loads, the pump fails if it exceeds any of the 3 component forces or any of the 3 component moments, or if it exceeds the API specified combined loading. E.G. if it is an API 610 pump, you should check the API 610 specification, as well as the API 610 module built into CAESAR.

If instead the manufacturer specified permissible forces and moments for his nozzles, then that is something you have to take up with the manufacturer, or otherwise address in your piping system.

Without more detailed information on the routing, I can offer the following generic recommendations:
• Too much weight on top of your pump? Spring can.
• Too much thermal growth axially into your pump? Add expansion loop. If on the suction, pass it back through the hydraulic analyst (i.e. process engineer.)
• Too much thermal growth laterally into your pump? Expansion joint (or loop). Again, process engineer. If on the discharge, ensure that the expansion joint has tie-rods if there's a turn close to the pump to avoid expansion joint accordion action.

This image is from Autopipe software which I am currently using but I guess both software will give me same result. This piping is for discharge nozzle(boiler feed pump) and higher loads are in Z-direction( or download direction) mostly due to thermal expansion and not so much due to gravity. This was a general question of if those kinds of results is ok or not. Using springs will solve the problem but cost limitation restricts its use. But if no other option is possible then may be using spring is the only way.

Your valves location contribute to high load due to more effort required by pipe to move up. try to use resting only (+Z) for your dummy leg instead of restriction in 2 ways direction.

Springs themselves aren't terribly expensive, although lead times, maintenace, etc, may be problematic. Lisega offers an option for dummy leg replacements.

Being that you basically have a "big" valve on a "small nozzle," I'm mildly surprised that dead weight isn't an issue. I would question whether the valve could be placed in the vertical, still be accessible, and mitigate enough of the overload. But I would envision the vertical load gets transformed into moment, which may hurt you more than help you.

If you have lift-off issues, a potential spring-less alternative would be to displace the small valve out of line with the nozzle via an expansion loop, but again, we do not know the physical constraints in this location.

Mr. Noorsyam, I have tried removing the support but has no impact what so ever in the system.

Mr. Michael Fletcher, you are right that gravity load, not stress, is an issue because of the valves but I was hoping for thermal expansion load to negate it. Even after the removing the support to allow them move in upward direction only, there is not much help. Moving horizontal valve to vertical will make difference but not enough. Space constraint is not helping in creating a loop or making a pivot to allow better flexibility. Thank you all for your help but I think spring is the best solution here or probably the only solution.

The only way thermal effects could mitigate your pump loads in this configuration is if the dummy legs somehow heated up faster and higher than your piping.

Even if the pipe were cryogenic, it looks like it could lift off the dummy legs, and thereby increase your pump nozzle loads.

If I didn't mention it above, I'll point out that Lisega offers a spring can that's designed to replace a base elbow support.

Yes, the dummy leg lifting is a problem. Thank you very much for the pipe support suggestion. I will consult with the material team about it.