Pipe Surge and Water Hammer Apparatus

Pipe surge and water hammer are two related but independent phenomena which arise when fluid flowing in a pipe is accelerated or decelerated. The associated pressure transients can be damaging to pipe work or components and systems must be designed to avoid or with stand them.

The equipment designed by clearly demonstrates the different effects resulting from gradual or instantaneous changes in fluid velocity. Effect of initial fluid velocity can also be investigated. Pipe surge resulting from a gradual change in fluid velocity is clearly seen as fluctuating changes in head in a surge shaft.

Water hammer resulting from a rapid change in fluid velocity is clearly seen as large changes in pressure monitored using a pair of transducers and indicated using an oscilloscope. The equipment comprises two stainless steel pipes connected to a constant head tank. A service module provides the water supply to the head tank and also incorporates a volumetric tank for flow rate measurement, sump tank, circulating pump and flow control valve.

Water enters the two test pipes via the constant head tank and discharges into the volumetric tank. A dump valve in the volumetric tank returns the water to the sump tank.

The pipe surge test section incorporates a clear acrylic surge shaft to enable visualization of its oscillatory characteristics to be demonstrated. A metric scale on the shaft permits the height of the oscillations to be measured. The test pipe terminates with a lever operated gate valve and separate flow control valve.