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The Blue Ridge Dam and surge tank

Isawa II power station surge tank

Surge tankFrom Wikipedia, the free encyclopedia

A surge tank (or surge drum) is a standpipe or storage reservoirat the downstream end of a closed aqueduct or feeder or a dam orbarrage pipe to absorb sudden rises of pressure, as well as toquickly provide extra water during a brief drop in pressure.

In mining technology, ore pulp pumps use a relatively smallsurge tank to maintain a steady loading on the pump.

For hydroelectric power uses, a surge tank is an additionalstorage space or reservoir fitted between the main storagereservoir and the power house (as close to the power house as possible). Surge tanks are usuallyprovided in high or medium­head plants when there is a considerable distance between the water sourceand the power unit, necessitating a long penstock. The main functions of the surge tank are: 1. When theload decreases, the water moves backwards and gets stored in it. 2. When the load increases, additionalsupply of water will be provided by surge tank.

In short, the surge tank mitigates pressure variations due to rapid changes in velocity of water.

Contents

1 Operation

2 Automotive surge tanks

3 Aircraft surge tanks

4 See Also

5 References

Operation

Consider a pipe containing a flowing fluid. When a valve iseither fully or partially closed at some point downstream, the fluid will continue to flow at the originalvelocity. In order to counteract the momentum of the fluid the pressure will rise significantly (pressuresurge) just upstream of the control valve and may result in damage to the pipe system. If a surgechamber is connected to the pipeline just upstream of the valve, on valve closure the fluid instead ofbeing stopped suddenly by the valve will flow upwards into the chamber hence reducing the surgepressures experienced in the pipeline.

Upon closure of the valve, the fluid continues to flow, passing into the surge tank causing the water levelin the tank to rise. The level in the tank will continue to rise until the additional head due to the height offluid in the tank balances the surge pressure in the pipeline.[1] At this point the flow in the tank and

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pipeline will reverse causing the level in the tank to drop. This oscillation in tank height and flow willcontinue for some time but its magnitude will dissipate due to the effects of friction.

Automotive surge tanks

The surge tank is utilized in automotive applications to ensure that the inlet to the fuel pump is neverstarved for fuel. It is usually only seen in racing or custom applications, especially in vehicles that willbe sustaining high lateral acceleration loads for extended periods of time.

Aircraft surge tanks

Aircraft surge tanks are used on a select few aircraft to ensure that fuel does not spill over onto theground when the fuel expands. These tanks must be periodically emptied to prevent fuel from spilling,which they do fairly often.

See AlsoHydraulic accumulatorWater hammer

References1. Marriott, M. (2009). Nalluri & Featherstone's Civil EngineeringHydraulics. Wiley Blackwell.

[[Category:Plumbing]——]

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Categories: Hydraulics

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