The necessary data, such as the physical mechanic properties, the hydraulic characteristics, the permissible Working pressure, and the suitable sizes of the hose, etc.
有些方面如物理力学性状、水力性能指标、允许工作压力、以及管材的适宜规格等方面也缺乏资料。
2
In this article, the factors that affect the max. permissible differential pressure of Roots vacuum pump are discussed. The methods of increasing it are discussed together.
文章分析了影响提高罗茨真空泵最大允许压差因素，提出了解决方法。
3
The main feature is that the maximum permissible plunger chamber pres sure curve is approximately equidistant above the actual pressure curve.