Pipe Surge and Water Hammer Apparatus

Pipe Surge and Water Hammer Apparatus

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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.

DEMONSTRATION CAPABILITIES:-
Demonstration of pipe surge
Determination of oscillatory characteristics of the surge shaft
Demonstration of frictional head loss between reservoir and surge shaft
Comparison between theoretical and measured pressure profiles produced by water hammer
Using a dual trace storage oscilloscope to record transient water hammer pressure profiles
Measuring the pressure profile characteristics
Determination of the velocity of sound through a fluid in a pipe
Demonstration of the effects of cavitations on subsequent cycles.

TECHNICAL SPECIFICATIONS:-
Pipe surge test pipe: stainless steel 22 mm I/D x 3 m long
Surge shaft : clear acrylic 40 mm I/D x 800 mm H
Service pump: centrifugal type, delivering 1.35 liters/sec at 3 m H20
Flow rate measurement: volumetric tank, stepped 0-40 liter high flows 0-6 liter low flows
Head tank: capacity 45 liters
A self-contained unit designed to demonstrate the phenomena of pipe surge and water hammer.
The unit includes two separate test pipes, service module and constant head tank.
Two pressure transducers provide electrical signals for connection to a dual trace storage oscilloscope with an integral printer output.
Straight pipes are used, rather than a coiled arrangement, to reduce distortion of the pressure wave.