The engine, as it cooled itself, sucked in air through the outlet hose, producing suction in the vacuum chamber, and so drawing the plunger down and compressing the spring.
当引擎冷却时，通过出口软管吸入空气，在真空管产生吸气，导致柱塞向下挤压弹簧。
2
There is emergency bilge water suction mouth in the engine room, which directly to the suction mouth of bilge pump.