(1) Pump will not overheat: powered by compressed air in the exhaust is an endothermic process of expansion pneumatic pump when the temperature is lower non-harmful gas emissions.

• （1）泵不会过热：压缩空气作动力，在排气时是一个膨胀吸热的过程，气动泵工作时温度是降低的，无有害气体排出。