Liquid intelligent turbine flowmeters come in a wide variety of models and types. The accurate and stable operation of flowmeters not only depends on the scientific and reasonable model selection and matching in the early stage but also on the standardized commissioning operation after procurement. To ensureduweyintelli Flowmeter Manufacturerthe measurement accuracy of flowmeters, extend the service life of equipment, and avoid equipment damage and measurement failures, the core precautions for putting liquid intelligent turbine flowmeters into operation after procurement are now detailed as follows.
Strictly follow the operation sequence for commissioning, opening, and closing
Flow meter start-up and shut-down operations must be carried out step by step. Depending on whether the pipeline is equipped with a bypass pipe, it is divided into two standard operating procedures. Rapid opening and closing of valves and instantaneous high-flow impact on equipment are strictly prohibited.
Operation of commissioning the flow sensor without bypass pipe
First, adjust the upstream valve of the flow sensor to a medium opening, then slowly open the downstream valve. Run the control equipment in a low-flow state for about 10 minutes to stabilize the pipeline flow field and equipment operating conditions. After the trial run shows no abnormalities, fully open the upstream valve, then gradually increase the opening of the downstream valve until it reaches the normal operating flow required by the process.
Commissioning operation of flow sensor with bypass pipe
Step 1: Fully open the bypass pipe valve, then open the upstream valve at medium opening, and slowly open the downstream valve; then gradually close the bypass valve to allow the flowmeter to operate stably at a low flow rate for a period of time. After the operating conditions are stable, fully open the upstream valve and completely close the bypass valve, making sure to confirm that there is no medium leakage from the bypass valve. Finally, fine-tune the opening of the downstream valve to adjust the flow rate to the standard operating conditions required for production.
Special commissioning requirements for high and low temperature fluids
For low-temperature and high-temperature special temperature media, the start and stop operations of the flowmeter need to control the temperature gradient to avoid sudden temperature changes that may damage the equipment and affect measurement accuracy. The operating principle is “slow heating, slow cooling, and smooth start and stop”.
Operation of Low-Temperature Fluid Commissioning
Before the pipeline is put into operation, the residual moisture inside the pipeline must be completely drained to prevent low-temperature freezing from damaging the pipeline and equipment. At the initial stage of medium introduction, the flow rate needs to be controlled at a very low level and operated for 15 minutes. After the temperature of the equipment and pipeline is initially adapted, gradually increase the flow rate to the normal operating standard. When the equipment stops flowing, it should also be shut down slowly to ensure that the pipeline temperature gradually approaches the ambient temperature smoothly, thus preventing equipment failures caused by sudden temperature changes.
High-temperature fluid commissioning operation
The operation, commissioning, and shutdown procedures for high-temperature fluids are consistent with the operating specifications for low-temperature fluids, ensuring that temperature and flow rate fluctuations are avoided throughout the process to guarantee the stable operation of core components such as the impeller and bearings inside the flowmeter.
General Operating Protection and Maintenance Precautions
Standardize valve opening and closing to prevent water hammer impact
The opening and closing of the valve supporting the flowmeter should be kept smooth and uniform throughout the process. If an automated control system is used to open and close the valve, it is recommended to adopt the two-stage opening and two-stage closing control method to effectively avoid the instantaneous impact of the medium on the impeller, prevent the occurrence of water hammer, and avoid equipment failures such as impeller deformation and bearing damage.
Monitor downstream pressure to prevent cavitation
Under the condition of low pipeline pressure, during the initial operation of the flowmeter, it is necessary to focus on monitoring the pressure downstream of the sensor under the maximum flow condition to ensure that the measured pressure is greater than the minimum pressure value (pmin) calculated by the formula. If the pressure does not meet the standard, timely corrective measures such as pressure stabilization and pressure regulation shall be taken to prevent cavitation in the pipeline, which could damage the measurement stability and equipment structure.
Regularly calibrate the meter factor to ensure measurement accuracy
The meter coefficients of flow sensors have all been calibrated by standard devices, and detailed parameters are recorded in the equipment calibration form. Users should properly keep the calibration materials and avoid losing them. During the long-term operation of the equipment, the meter coefficients may shift due to factors such as bearing wear and medium scouring, so offline or online calibration work needs to be carried out regularly. If the flow accuracy is detected to exceed the allowable error range, the flow sensor should be replaced promptly to ensure the accuracy and reliability of the measurement data.
Standardize medium switching and pipeline pigging operations
During the stages of product changeover and equipment shutdown, pipelines for transporting media such as refined oil need to regularly conduct pipeline pigging operations. During the operation, parameters such as the flow direction, flow rate, pressure, and temperature of the pigging medium must strictly comply with the specifications of the turbine flowmeter equipment. Exceeding the parameter limits or improper operation will directly lead to a decrease in measurement accuracy, and in severe cases, may cause irreversible damage to the equipment.
Regularized inspection and troubleshooting to ensure long-term operation of equipment
Establish a regular inspection mechanism for the normal operation of flow meters, monitor the operating status of equipment in real time, and immediately shut down the equipment for troubleshooting, rectification, and repair upon detecting any abnormalities. During daily inspections, it is possible to determine whether there are abnormal noises in the equipment through auditory means, and also to monitor the output waveform of the detection coil with the help of an oscilloscope. Once the waveform or impeller operation is abnormal, the equipment must be promptly disassembled to check for wear and damage to internal components.
Meanwhile, it is necessary to regularly check the operating conditions of the filter, determine whether the filter is blocked by the pressure difference between the inlet and outlet pressure gauges, promptly clean up debris, and ensure smooth pipeline flow; regularly discharge the gas precipitated from the liquid in the degasser to avoid gas accumulation affecting the accuracy of flow measurement, and comprehensively ensure the long-term stable operation of the flowmeter.