science

Surge tank

Surge tank is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Surge tank rather than just read about it. In short: A surge tank (or surge drum or surge pool) is a standpipe or storage reservoir at the downstream end of a closed aqueduct, feeder pipe, or dam to absorb sudden rises of pressure, as well as to quickly provide extra water during a brief drop in pressure. In mining technology, ore pulp pumps use a relatively small surge tank to maintain a steady loading on the pump.

Key takeaways

Surge tank belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Surge tank to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Surge tank from memory before moving on to harder problems.

Reference excerpt

A surge tank (or surge drum or surge pool) is a standpipe or storage reservoir at the downstream end of a closed aqueduct, feeder pipe, or dam to absorb sudden rises of pressure, as well as to quickly provide extra water during a brief drop in pressure. In mining technology, ore pulp pumps use a relatively small surge tank to maintain a steady loading on the pump. For hydroelectric power uses, a surge tank is an additional storage space or reservoir fitted between the main storage reservoir and the powerhouse (as close to the powerhouse as possible). Surge tanks are usually provided in high or medium-head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock. The main functions of the surge tank are:

When the load decreases, the water moves backward and gets stored in it. When the load increases, the additional supply of water will be provided by a surge tank.

Operation Consider a pipe containing a flowing fluid. When a valve is either fully or partially closed at some point downstream, the fluid will continue to flow at the original velocity. In order to counteract the momentum of the fluid, the pressure will rise significantly (pressure surge) just upstream of the control valve and may result in damage to the pipe system. If a surge chamber is connected to the pipeline just upstream of the valve, on valve closure, the fluid, instead of being stopped suddenly by the valve, will flow upwards into the chamber, hence reducing the surge pressures experienced in the pipeline. Upon closure of the valve, the fluid continues to flow, passing into the surge tank causing the water level in the tank to rise. The level in the tank will continue to rise until the additional head due to the height of fluid in the tank balances the surge pressure in the pipeline. At this point the flow in the tank and pipeline will reverse causing the level in the tank to drop. This oscillation in tank height and flow will continue 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 never starved for fuel. It is typically used in vehicles with electronic fuel injection or that will be sustaining high lateral acceleration loads for extended periods.

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

See also Hydraulic accumulator – Reservoir to store and stabilise fluid pressure Hydropneumatic device Water hammer – Pressure surge when a fluid is forced to stop or change direction suddenly Water tower – Elevated structure supporting a tank

References

Illustrations

Worked examples

Example 1 — a first encounter with Surge tank

Start with the simplest possible case. Write down what Surge tank claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Surge tank before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Surge tank ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Surge tank

In research: Surge tank appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Surge tank in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Surge tank is common in secondary-school and first-year university syllabi. It links to neighbouring topics Hydraulics, Plumbing, so understanding it makes those chapters shorter.
In everyday life: Look for Surge tank outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Surge tank in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Surge tank means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Surge tank out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Surge tank in simple terms?

Why does Surge tank matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Surge tank?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Surge tank.