It seems to me that pump vibration isolators need to support:
- The weight of the pump
- The weight of the water in the pump
- The weight of the water (only) in the drop to the pump
The supplier of vibration isolators on my project does not seem to share this view.
I understand that pump manufactures want none of the pipe weight to bear on their connections. The pipe hangers can be adjusted to prevent that.
A braided flex connector can prevent the thrust force due to pressure in the pipe from being an issue at the vibration isolators.
But the water weight in the drop to the pump seems to have no support other than what is provided by bearing on the bottom of the pump’s volute. This weight is transferred to the vibration isolators.
In the diagram below (considering only on the discharge side of the pump to explore the concept), the vibration isolators need to support 8 feet of water in the 14” diameter drop.
The water weight is 59.75 lb/ft in the chart here: Pipe weights per foot
So the water weight (due to only the discharge pipe) on the vibration isolators seems to be:
(59.75 lb/ft) * (8 feet) = 478 lbs
Is this correct? Or are the vibration isolators not subjected to the water-weight in the drop for some reason?