英语翻译Closuresealshallholdpressurefrombelowatalowpressureof1,7MPaandatahighpressureequaltothemaximumratedworkingpressure主要是介词分别限定谁啊?

Question

英语翻译
Closure seal shall hold pressure from below at a low pressure of
1,7 MPa and at a high pressure equal to the maximum rated
working pressure
主要是介词分别限定谁啊?

Answer 1

密封条将保持自1.7兆帕的低压压力,一直到等同于最高额定工作压力的高压.
from below 是词组,意即“自下,从下（面）”,与at一起作为复合介词修饰a low pressure...