what is water hammer forming;its a unconventional forming process but no notes are available in books.pls tel

Answer 1

Water Hammer forming is a technique of producing thin walled tubes by inducing pressure into the tube via starting and stopping a flow of water under high pressure ie
Water Hammer Forming of Tubes makes use of a plane stress wave produced in the water column inside the tube and directed towards tube wall by a reflector. The arrangement of the system also produces some axial compression of the tube. Expansions between 0/36 to 0/40 (true circumferential strain) are attainable for thin walled copper tube.

Answer 2

Water Hammer Forming

Answer 3

The kind I know of, is common in metal pipes.

The sudden fluctuation of pressure can cause the cavitation which can set up harmonics, and the pipe makes noise.

In olden days it was eliminated by adding stand pipes, in some locations. To-day more compact version are available from plumbing supply store.

You can have one on any line from header line (they are call hammering arresters) and one on header and main line, one on even hot water line.