Anchor Bolt Design - Pump Anchorage

[WBell]

I am tasked with designing the anchorage for a vertical turbine pump at a water treatment plant. The guidance document for dynamic machine loads is ACI 351.3R-18, "Report on Foundations for Dynamic Equipment", which describes the calculation procedure for unbalanced loads. I also have the nozzle loads at the discharge point and according to API 610,"Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries", the nozzle loads must be carried into the foundation through the anchor bolts.

The vendor supplied nozzle loads are for a 24 inch nozzle and are upwards of 3 kips force and 9 kip-feet moment in each direction. Before I committed to evaluating each possible combination of force and moment, I wanted to ask if anyone else had experience in this type of analysis and would comment on the approach I am taking.

Thank you for your input.

 

[WARose]

Not trying to be a wiseguy here.....but....it's hard to comment on "the approach [your are] taking" without knowing what that approach is. What are you seeking comment on? If the nozzle loads seem right? The code you are using? I (for one) don't follow the question here.

 

[JStephen]

I was just glancing through one of the AWWA pump standards, and it references "Hydraulic Institute" standards for foundation design and related topics.

 

[AUCE98]

Typically designing for the force generated by the pump in a lock up situation is how I will design the anchorage with no additional information. Max Torque formula at lock up taken as T= HP*5252/RMP, where HP=horsepower and RMP is the motor speed. The torque is then resisted by the couple between anchors.

 

[WBell]

Thank you for the comments. I am trying to design the anchor bolt given a vendor supplied baseplate size and hole pattern. As I mentioned, the pump manufacturer has supplied maximum nozzle loads, which when applied simultaneously in all three directions, in combination with unbalanced rotor forces, or the locked rotor forces, would be overly conservative.

I am preparing a bounding analysis that is not overly conservative. Combining the nozzle loads and locked rotor torque should envelope the anchor bolt loads and I intended to combine the forces/moments from the nozzle loads using SRSS.

I was hoping to find a Standard or Guidance document to support this approach and as yet have not found one.

 

[bones206]

I’d probably get clarification on the vendor for which loads they considered to act simultaneously and which are separate load cases.

 

[azcats]

Your question reminded me of this thread about pump & equipment anchors: [URL unfurl="true"]https://www.eng-tips.com/viewthread.cfm?qid=473362[/url]

Not directly related to your OP, but might be some interesting reading.

 

[dik]

in SMath:

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[bones206]

I believe the nozzle stress checks can be based on the resultant forces and moments, so you may be able to just check one load case with the resultants applied to the anchor group. I’d still double check with the mfr since it’s a pretty big nozzle.

 

[Liam Nesson]

I havent worked on this type of pump, however i have worked on lots of horizontal and the odd vertical pump.

Any way to get the vendor to provide the anchor loading? Typically we would include this requirement at purchasing stage.

As for nozzle load combinations, do you have a pipe stress engineer on the job? They should provide individual load cases for nozzle loads. They might be significantly less than the allowable if the system is well balaced. Then maybe you can ignore them.