Safety is the core of metering skid commissioning.

The core of meter skid debugging is to first perform safe replacement, then conduct unit-by-unit debugging, and finally carry out joint debugging and verification. Throughout the process, strictly control pressure, flow, sealing, and interlocking to ensure accurate measurement and stable operation.
I. Pre-debugging Preparation (Safety and Compliance)
Materials and Personnel
Prepare design drawings, equipment manuals, metrological verification certificates, debugging plans, and emergency response plans.
Debugging personnel must be certified to work, familiar with the process flow, valve operations, and emergency handling.
Inspection of Equipment and Instruments
Confirm that all valves, flanges, and instruments are installed in place, and the torque of fasteners meets the standards.
Pressure gauges, flowmeters, pressure transmitters, shut-off valves, relief valves, etc., are verified to be qualified and within the validity period.
Check that filters, pressure regulators, and flowmeters are free of impurities and damage; signal pipes and pressure-taking pipes are unobstructed and leak-free.
Safety and Replacement
The system is purged and replaced with nitrogen. For gas skids, the oxygen content should be ≤ 2%, and gas can be admitted only after passing the inspection.
Prepare leak detection fluid, explosion-proof tools, fire-fighting equipment, demarcate a warning zone, and prohibit unauthorized personnel from entering.
II. Step-by-Step Debugging Process (Proceeding by Unit)
Debugging of Inlet and Filter Unit
Slowly open the main inlet valve (first the bypass, then the main valve), and gradually increase the pressure to the design pressure.
Fully open the root valve of the pressure gauge, and after observing that the pressure is stable, check that there is no leakage at flanges, valves, and welds.
Open the valves before and after the filter: first open the valve after the differential pressure gauge, then the valve before it, and observe that the differential pressure is normal.
Slowly discharge sewage, close the sewage valve after it is completely discharged; debug each branch one by one using the same method.
Debugging of Metering Unit (Core)
Parameter setting: Configure the range, temperature/pressure compensation coefficient, compression factor, alarm threshold, etc., on the flow computer/flowmeter panel to be consistent with the design.
Zero calibration: When the medium is stationary and the valve is fully closed, reset the output of the flowmeter and transmitter to zero.
Gas test operation: Slowly open the valves before and after the flowmeter to avoid gas flow impact; observe that the flowmeter rotates/displays normally without abnormal noise.
Accuracy verification: Use a standard meter/volume tube for three-point calibration (25%, 50%, 100% of the range), with an error ≤ the allowable value (e.g., ±0.5%).
Integration and communication: Check that the flow integration, historical records, and 4–20mA/communication output are normal.
Debugging of Pressure Regulation Unit (Common for Gas/Liquid Skids)
Confirm that the ball valves of the signal pipe and pressure-taking pipe are fully open, and the root valve of the pressure gauge is fully open.
Slowly introduce the front pressure, and first set the shut-off pressure → relief pressure → working pressure (from high to low).
Test that the closing pressure, response time, overpressure shut-off, and low-pressure shut-off functions are normal.
1+1/2+0 pressure regulation: First adjust the main circuit, and put it into operation slowly after passing the inspection; relieve the pressure of the standby circuit to avoid diaphragm fatigue.
The outlet pressure is stable at the set value, with a fluctuation ≤ ±5%.
Debugging of Safety Interlock and Control System
Test alarms and interlocking actions (shut-off, relief) for overpressure, underpressure, excessive differential pressure, abnormal flow, etc.
Check that the HMI/upper computer display, remote control, and data recording are normal.
Simulate power failure and instrument gas cut-off to confirm that the safety status and reset logic are correct.
System Joint Debugging and Load Test
Fully open the inlet and outlet valves, and run continuously for ≥ 4 hours under 20%–100% load.
Monitor that pressure, flow, temperature, and differential pressure are stable, with no leakage, abnormal vibration/noise.
Compare the metering data with the standard value, and ensure that repeatability and linearity are qualified.
Record all debugging data and form a debugging report.
III. Key Debugging Points (Must-Control Items)
Safety First
Operate valves slowly throughout the process; it is strictly forbidden to open or close them quickly to prevent water hammer or gas hammer from damaging equipment.
Replacement, pressure increase, and pressure reduction must be carried out in accordance with regulations; overpressure and negative pressure operation are strictly prohibited.
If a leak is found, immediately stop debugging, relieve pressure, handle it, and continue only after it is qualified.
Guarantee of Metering Accuracy
The straight pipe sections before and after the flowmeter must meet the requirements (front ≥ 10DN, rear ≥ 5DN) with no flow-disturbing parts.
The medium must be free of droplets and impurities to avoid wear and zero drift.
Temperature and pressure compensation parameters are set according to actual working conditions and reviewed regularly.
Reliability of Pressure Regulation and Interlock
The set values of shut-off/relief pressure are strictly in accordance with the design and must not be changed arbitrarily.
Pressure regulators and shut-off valves act sensitively, close tightly, and have no internal leakage.
The interlock logic has undergone simulation tests to ensure "shut off when it should be shut off, relieve when it should be relieved".
Stability of Instruments and Systems
All instruments are verified to be qualified, with correct installation directions and pressure-taking positions.
Electrical and automatic control systems are well grounded, anti-interference, and have normal communication.
The duration of joint debugging is sufficient, with no drift or false alarms observed.
IV. Post-Debugging Conclusion
Organize debugging records, parameter settings, and calibration data for filing and future reference.
Provide on-site training for operators, explaining key points of operation, inspection, and emergency response.
Hand over for use, enter the trial operation stage, and continuously monitor for 72 hours.