Dear Coade Members,

This is my first dynamic analysis on Water Hammer, i have some queries related to it, can u please clarify....

I am following the water hammer procedure as in Caesar-II application guide.

In our case, Pipe size 10" Sch. 40, Velocity 2m/s, design pressure 50 barg and temperature is 85 Deg C.

The pipeline starts from source well and connects to the pump suction. The pipeline length is approximately 1 km between the connections.

There are many bends in our problem. The elbow pairs we are considering in our problem is the first 300 meter pipeline from the pump suction point and we considering 4 elbow pairs for the water hammer analysis.

In Caesar-II guide it is mentioned that two elbow pairs at node 45 to 75 and 90 to 110 are considered for water hammer. To calculate the time duration of the load between the elbow pair, the length L of 90 feet is taken for 45-75 elbow pair and 75 feet is taken for 90-110 elbow pair.

My query is why the reference length shall not be taken from the source of water hammer, in my case we are considering the source of water hammer as the pressure control valve.
(i.e.) let assuem L1 be the length for the first elbow pair from the source and the load duration may be t=L1/c.

To calculate the length for the second elbow pair, why not the length shall be taken from the source instead between the elbow pairs (ie) L2 = L1 + length of second elbow pair. Also the unbalanced force might have reduced some how due to the impact in the first elbow pair.

Also why we are going for a separate spectrum for each elbow pair. It seems that the force will be high when the pressure wave hit the first elbow pair and get diminishes due to friction and successive elbow pair when it travel along the pipeline.

Also in Caesar-II example, for generating the spectrum table the input seems to have some error (i.e) for force, the value is used as 1.0.

Instead of providing a big anchor support to limit the displacement, shall i provide water hammer suppressors...

Please clarify........