There is a new tool in the sea. It can withstand pressure up to 2,000 feet.

海洋里有一种新工具。这种工具可以承受高达2000英尺的压强。

So when you finish brewing espresso in many machines, it discharges the pressure up through the group head, and that causes the puck to expand.

因此，当您在许多机器中完成冲泡意式浓缩咖啡时，它会通过组头释放压力，这会导致冰球膨胀。

You can think of it as a chemical “pump” which generates incredibly high pressure— up to 9 times that of a car tire— in the sieve tubes.

您可以将它想象成一个化学“ 泵” ， 它在筛管中产生难以置信的高压—— 高达汽车轮胎的 9 倍。