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Research on new approaches to metering in pressure regulation station areas: With the development of the urban gas industry, and as this sector transitions from a socialist planned economy to a socialist market economy, excessive differences between supply and demand prices have become a technical and economic management issue that needs to be addressed urgently in the gas industry. Currently, the supply and sales price difference for pipeline gas in China’s gas industry is generally high. The main reasons for this include issues related to pipeline leaks, the reliability of metering equipment, and operational management, and it is difficult to conduct quantitative analysis. Over the years, gas companies across the country have been constantly seeking problems in terms of technology and management, and working to find effective solutions. In recent years, Tianjin Natural Gas Company has strengthened management and research efforts, taking a series of effective measures that have led to significant achievements in reducing discrepancies. Additionally, the company has conducted research on new approaches for metering in pressure regulation stations, and these approaches are being gradually implemented on a wider scale. I. Pilot project for metering in the pressure regulation station area: In 1997, the company decided to install metering devices at the pressure regulation stations as a pilot project. The location selection for these pilot stations was a key issue. Following a feasibility study, the company decided to install local metering devices at the Wen Gongli pressure regulation station located in the Hedong branch office. The reasons for choosing this location are as follows: 1. The Wen Gongli pressure regulation station is situated within the premises of the Hedong branch office; it is an independent and enclosed pressure regulation station that serves approximately 4,000 gas customers. There is only one service station responsible for billing, which facilitates accurate analytical assessments. 2. In addition to supplying 4,000 residential customers, the pressure regulation station in Mun-gong-ri provides only a small number of welfare customers as well as gas for internal use at the facility and the Mun-gong-ri service station. 3. The pressure regulation station in the Wen Gong facility is located within the Hedong office, which facilitates construction management as well as the collection and analysis of operational data. 4. The pressure regulation station in the Wen Gong facility has the conditions for installing metering instruments and modifying pipelines, so there is no need to build new buildings. II. Selection of measuring instruments in the voltage regulation station area: Based on thorough research and evaluation, the company’s technical staff installed a set of Delais measuring instruments after the outlet of the RTJ-216-A type voltage regulator; these instruments have been operating well to this day. 1. Principles for selecting measuring instruments: Measuring instruments must have high precision, low cost, strong functionality, and a high degree of automation. 2. Features of Delaisi measuring instruments: Delaisi measuring instruments boast a wide flow range, high accuracy (+1%), a large ratio of measurement ranges, a low starting flow rate, and are stable and reliable. Therefore, this measuring instrument is quite suitable for metering in pressure regulation station areas in China at present. 3. Select the 38M Delaisi measuring instrument. Based on the technical specifications of the Delaisi measuring instruments and the current situation of large pressure fluctuations in the pipeline network, and after thorough verification and flow rate calculations, we have chosen the 38M model of Delaisi measuring instruments. Its maximum rated flow rate is 1075 cubic meters per hour, while its starting flow rate is 1.6992 cubic meters per hour. From the current operating conditions, it meets the requirements for measurement; its accuracy and stability satisfy the needs for accurate measurement during operation. III. Installation of regional measuring instruments 1. Installation at the outlet of the pressure regulation station Given the large fluctuations in external network pressure, installing such instruments at the inlet of the pressure regulation station would require the use of devices for pressure and temperature compensation, as well as filters and valves. However, the existing space in the pressure regulation station limits the possibility of installing these devices. Therefore, during the pilot project at the Wengongli pressure regulation station, the measuring instruments were installed at its outlet. Analysis of the operating conditions after installation shows that the high outlet pressure and poor pressure stability are caused by this ； During peak gas usage, the instrument makes loud vibrating noises ； Since no filtering device has been installed, it is often removed and cleaned during off-peak gas usage periods. 2. Installed at the inlet of the pressure regulation station: If there are no constraints related to the size of the pressure regulation station, installing the measuring instruments at its inlet can overcome the aforementioned disadvantages. This allows for a wider range of applicable pressures, improves accuracy, and enables optimal operation. Therefore, it is recommended that when installing metering instruments at regional voltage regulation stations, they should be placed at the inlet of the station. IV. Analysis of gas consumption patterns 1. Peak usage levels on a monthly, weekly, daily, and hourly basis. The pressure regulation station in Gongli serves primarily to supply gas for residential use; it serves 4,454 households. In addition, it supplies gas for the use of the Hedong branch office and service stations (which have separate metering devices), and the gas consumption from these sources accounts for only 1.5% of the total gas consumption. The peak gas consumption occurs during the times when meals are prepared in the morning, afternoon, and evening; the highest hourly peak is 390 cubic meters, with an average hourly demand being 5.3 times that value. Table 1 shows the load and average household load values at the Wen Gongli pressure regulation station from July 1997 to June 1998, during peak weeks, peak days, and peak hours. Table 1: As can be seen from Table 1, the peak monthly, weekly, daily, and hourly loads occur on the same date, which happens to be the period of high gas demand during the Spring Festival; the average load per household is 12.25 cubic meters per month. The average household load is 11.63 cubic meters per month during the non-heating period, and 13.22 cubic meters per month during the heating period; in other words, the gas consumption in winter is 1.14 times that in summer. Table 2: From Table 2, we can see the coefficients for peak months, peak weeks, peak days, and peak values. 2. Gas usage patterns: The residential users at the pressure regulation station in Wen Gong have typical gas usage patterns, with peak demand occurring during meal preparation times (see Figure 1): in the morning from 8:00–9:00, at noon from 11:00–12:00, and in the evening from 18:00–19:00. V. Analysis Conclusions and Recommendations: Overall, the pilot project involving the installation of measuring instruments in the regulation station area at Wen Gongli showed that the selection of these instruments was scientific and reasonable, and the data collected regarding their operation were reliable and accurate. This achieved the objectives of the pilot project and created the conditions for the widespread adoption of such measuring instruments in regulation station areas. 1. Based on data analysis, the leakage rate of the low-pressure courtyard pipeline network at the outlet of this voltage regulation station is zero, which provides a scientific basis for pipeline network inspections and technical upgrades. 2. Within the gas supply area of the pressure regulation station in the Wen Gong area, the average monthly gas consumption per household is 0.3 cubic meters higher than the target charging figure set by the company. Therefore, the planned charging targets set are reasonable and feasible. It is recommended to strengthen charging management in the future to keep the proportion of households in arrears or with zero charges below 5%. 3. Based on the analysis of operational data, the discrepancy is 24.18% in winter and 12.09% in summer. The average discrepancy is 18.15%. There are many factors at play, but it is imperative to improve management. 4. Strengthen the management of metering instruments for end-users. The accuracy of meters is crucial for minimizing errors; it is recommended that each district maintain records of civilian meters, enforce regular calibration of gas meters, and require the replacement and sealing of meters to improve the measurement accuracy of civilian meters. 5. By using service stations as billing points and installing metering devices at pressure regulation stations or main pipelines, along with appropriate incentive measures, a contracting system based on the number of metering devices can be implemented. This approach will surely change the current situation of high billing discrepancies and yield significant economic benefits.