Technology · Level 3 · 199 words

The Push in the Pipe

Original passage © Studio AM, written for Fluency.

Clean water in a tank is still useless. It has to reach a fifth-floor kitchen, and it has to arrive with enough force to fill a glass in seconds. That force is pressure, and a city buys it with height.

The oldest method is the simplest. Pump the treated water up into a tall tank and let gravity do the rest. The higher the tank stands above the taps, the harder the water pushes when a tap is opened. This is why a water tower sits on the highest ground a town owns, or on legs that lift it clear of the roofs.

A tower also buys time. Pumps run at a steady rate, but people do not use water at a steady rate; a city wakes, washes, and cooks inside the same hour. The tank fills through the quiet night and drains through the busy morning, so the pumps never have to be sized for the worst minute of the day. When the power fails, the tower holds the pressure up until it empties.

The same pressure that serves the fifth floor also pushes on every joint in the network. Where a pipe is weak, pressure finds it.

Comprehension questions

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4 questions
1. What is the passage mainly about?

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A. Height gives a water system its pressure, and that pressure both serves buildings and strains pipes.
The passage explains how height makes pressure, lists what the tower buys, then closes by turning that same pressure into a problem. Only the first choice holds both halves.

2. According to the passage, what does a tower let a city avoid?

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C. Sizing its pumps for the worst minute of the day.
The third paragraph says the tank fills at night and drains in the morning, so the pumps never have to be sized for the worst minute of the day.

3. In this passage, "pressure" is best understood as

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D. the force that pushes water out of a tap
Pressure is introduced as the force that fills a glass in seconds, and at the end it is the force pushing on every joint. It is a push, not a weight, a speed, or a demand.

4. The last two sentences suggest that

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A. the height that makes taps work also makes leaks more likely
The passage says the same pressure serves the fifth floor and pushes on every joint, and that pressure finds a weak pipe. The benefit and the risk come from one cause.

Source: Written for Fluency. Original passage © Studio AM, written for Fluency.