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how long do you think the pressure in the gas lines will stay up once the pumps are turned off? And how do you think those pumps are controlled?
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Gas pressure is maintained by gasometers, which work by gravity, so pressure will stay up until the gasometer is empty even if there is a total power outage. When the gasometer needs to be filled I should think the pumps are (or can be) operated manually.
Biting the hand that feeds IT
