信息来源: 华恒 | [ 2019-04-10] 点击量: 239


  How to deal with the common problems in the application of orifice flowmeter?There are always many uncertainties in the application life.Orifice plate flowmeter is a process control and measurement instrument widely used in petroleum,chemical industry,metallurgy,electric power,heating,water supply and other fields.What are the problems of orifice flowmeter in use?
  Orifice plate flowmeters are generally vulnerable to the influence of measured fluid characteristics,instrument performance installation and environment.
  Because of the nature of natural gas itself,complex changes will occur with the change of ambient temperature,thus affecting the measurement accuracy of flowmeters.For the measurement of natural gas,the working temperature and pressure of natural gas must be determined first.Low density gas is difficult for some measurement methods,so it is necessary to change the selected measurement methods,or make temperature and/or pressure correction to ensure the accuracy of measurement.
  The orifice flowmeter itself can also cause errors,such as orifice plate entrance right angle sharpness,diameter size and calculation inconsistency,orifice plate thickness error,orifice accessories Produce step,eccentricity,orifice plate upstream end flatness,ring chamber size produce step,eccentricity;pressure taking position,welding,welding seam prominent,pressure taking hole processing is not standardized or blocked,throttle parts of different axes and so on.These factors may affect the repeatability of orifice plate and the measurement accuracy.If the output characteristic of the instrument is non-linear,the influence will be more prominent.
  The installation error caused by the deviation of pipeline layout is universal,and the main reason is that the site can not meet the requirements of the length of straight pipeline section.Although orifice flowmeter installation can be used normally,some performance parameters and hardware aspects of the instrument have also changed due to the changes of the environment conditions and expectations,which will change the measurement results of the flowmeter.
  The orifice plate flowmeter designed,manufactured and calibrated according to the national standard does not need real-flow calibration.It has high accuracy,simple structure and low manufacturing cost.However,the pressure loss is the largest in all standard throttling devices,and it is not suitable for situations requiring low pressure loss.The standard orifice plate is widely used in petroleum,chemical,metallurgical,power and other industries.