To experimentally investigate it, needle valves and transparent glass tubes with flow channels similar to that of safety valves were used instead of the safety valve.
采用针阀代替安全阀，实验研究了安全阀进口干度、阀开度对安全阀及下游管路中流动堵塞的影响。
2
Flat glass and precise graduation scale give more needle accuracy and high visibility.
平板玻璃和精确毕业规模给予更多针准确性和较高的知名度。
3
The present paper has described the die made by chromium car - bide for forming mass spectrometer needle and double curved surface glass tube in surface analyzing instrument.