Here is some more info, in response to an email I received.

I am not concerned about the mining hose, as that is not part of my scope. This is a very small job that we have. The client (or someone else) is going to take care of the mining hose section, and we are going to design the steel pipe section.

The hose is not underground, it is not in a mine. It is on a floating plant, in a small lake. There is two barges, one with the process plant on it, and one with the mining barge on it. The process barge stays basically stationary, but the mining barge moves around sucking up slurry and pumping it to the process barge. The two barges are connected by about 100m of mining hose, which is attached to and floating on lots of little pontoons.

The flexible mining hose section meets the process barge, from there on it is a steel pipe system within the process barge.

The is an existing 600mm line, we are adding another 400mm line. The existing mining hose is restrained quite well to each pontoon, we assume the new line will be restrained in the same manner. I have been asked to analyse only the steel pipe section.

I am only worried about the water hammer pressure waves in the steel pipe system. I would have thought that the low elastic modulus of the mining hose would dampen most of the pressure waves. We have assumed the elastic modulus of the mining hose to be less than FRP pipe.

If I did apply a water hammer force to my steel pipe section, what force would I use? I would've thought that I would've used the force calculated in the mining hose, since that is where the source (the pump) is.