When a pressure is less than atmospheric pressure it is called a vacuum. 某种压力低于大气压力的状况被称作真空。
Vacuum pressure valve of the valve is below standard atmospheric pressure. 真空阀工作压力低于标准大气压得阀门。
Pressure in the compressor system to be dropped to atmospheric pressure level! 将压缩机系统内的压力降至大气压！
a space in which the pressure is significantly lower than atmospheric pressure 压强明显比大气压强低得多的空间
A space in which the pressure is significantly lower than atmospheric pressure. 真空般状态压强明显比大气压强低得多的空间
Sap flows out when the pressure inside the tree greater than the atmospheric pressure. 当树内压力很大程度上大于大气压力时, 树液就会流出来。
Sap flows out when the pressure inside the tree is greater than the atmospheric pressure. 当树的内部压力大于大气压力的时候树液就会流出。
When the external pressure is below atmospheric pressure, the boiling point will be lower. 当外界压强低于一个大气压时，水的沸点就降低。
If the gascollecting vessel was kept under atmospheric pressure, it would be called differential pressure accumulation leak detection. 若集气容器保持常压或低压, 即形成正压差累积法检漏。
This mill specially gives birth to the atmospheric pressure style and low pressure style save energy environmental protection water tank business. 本厂专业生产气压式、低压式节能环保水箱的企业。