Consult regarding the operating flow rate of the control valve
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This post was last edited by Qixian_LUPA on 2020-7-24 at 12:11. We have chosen Chuanyi pneumatic control valves; these valves have a diameter of DN150 mm. When in the three-return mode, the medium is hydrogen. The exhaust volume of the reciprocating compressor is 5453 Nm3/h, with the pressure at the third outlet being 1.432 MPa and the pressure at the first inlet being 0.69 KPa. What is the flow rate under the condition where the backflow valve is open by 25%? Urgent request: handshake
It would be more appropriate to choose the instrument control section for this topic...
This post was last edited by ZhiGE on 2020-7-26 08:08. 1. It is necessary to know the CV value; the CV value on the nameplate is not clear； 2. It is necessary to know the relationship between the opening degree and the CV value (in the form of a curve), that is, the valve characteristics (fast opening, linear, etc.); this information can be found in the technical specifications. Calculate the CV at 25% opening ； 3. Calculate the volumetric flow rate of the gas using the following formula (Q=CV*moles) ； 4. Meaning of letters in the formula
Received, thank you! I really can’t understand this; it would be convenient if there were a calculation software.
4th Floor, Smart GE Friend: Hello! The CV value on the nameplate is 44; can this flow rate be calculated? It would be great if you could help with the calculation. Thank you! :hug:
In addition to the conditions mentioned above, it is also necessary to know the piping conditions, that is, the pipe resistance, which relates to the resistance distribution coefficient s in the operating characteristics of the control valve.
The piping at both ends of the control valve is DN100 in diameter
It’s not a matter of whether there are experts or not; it’s that the conditions of your question are not sufficient for others to answer it. Logically, only a flow meter can measure it with accuracy. Even in estimates, apart from providing a more detailed explanation of the piping layout, pressure gauges must be installed accurately before and after the control valve, and the opening degree also needs to be calibrated.
What to do if a flow meter is available but not allowed? Do I need to calibrate it too?