What to do with the back air duct of the E+H mass flow meter?
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Behind the E+H mass flow meter, if the pipe is empty, the measurement will not be accurate – the value will be lower. There are a dozen or so automatic ball valves behind this pipe, and it’s unclear which valve is leaking, or whether the liquid is flowing back into the storage tank. What should I do? If there is an empty tube in front of the flow meter, meaning gas flows through the front section while liquid flows when the tube behind is full, will this cause the mass flow meter to give inaccurate readings?
I didn’t quite understand it, but adding backpressure at the end can prevent underfilling in the tube
In other words, there is dissatisfaction with the management; how can accuracy in measurement be ensured? What is backpressure?
It’s definitely not allowed when the pipe is not full; to have it approved, the pipe must be full, as full-pipe measurement is a fundamental requirement for mass flow meters. Back pressure is achieved by installing a back pressure valve; it opens when the pressure exceeds a certain level, which helps to reduce the occurrence of empty tubes.
First, it seems you are asking two questions
Valve leakage needs to be addressed on-site; a check valve can be installed to prevent backflow. If there is gas upstream of the flow meter, it will certainly have an impact when starting to feed material. Flow meters cannot accurately measure flow rates in a gas-liquid mixture. If this gas is removed within a short period of time, the problem isn’t severe; however, if there is a long section of gas upstream, the impact is significant, and it becomes necessary to address the issue of air in the pipeline.
As long as there is liquid in the front section of the pipe, it does not affect the measurement; however, a gas-liquid mixture can impact the actual measurement. You should strive to keep the pipe fully filled, identify the valves with internal leaks, and replace them – reverse flow must be avoided
Placing the flow meter at the lowest point can prevent airlocks
If the flow meter is dealing with a two-phase flow, it will issue an alarm, along with an alarm code