Analysis of Failures and Maintenance of Valves in Long-Distance Natural Gas Transmission Pressure Pi
2025-02-28 09:59:11
Introduction
In recent years, China's economy has continued to develop rapidly, and the high growth of industrial and real economies has driven increasing energy demands. Natural gas, as a key energy source for advancing energy transition and ensuring energy security, is primarily transported via long-distance pipelines to achieve efficient utilization. Valves in long-distance natural gas transmission pipelines are critical pipeline facilities, functioning to prevent gas leakage, mixing, and other issues. Therefore, timely maintenance and regular inspection of pipeline valves are essential prerequisites for ensuring the safe and stable operation of natural gas transmission pipelines. The core function of valves is to alter the flow direction of natural gas as needed, enabling control over transportation, isolation, and connection of the medium. Regular valve maintenance enhances safety, reduces failure risks, and ensures optimal performance.
Currently, natural gas is mainly transported through long-distance pressure pipelines. These pipelines have become a vital mode of natural gas transmission, relying on pressurization of internal fluids to enable flow. The normal operation of long-distance natural gas pressure pipelines depends on valves, which regulate flow rate, velocity, and pressure. The structural stability of valves is crucial for pipeline reliability. However, the complex structure of these valves often leads to leakage during assembly or pipeline connection. Additionally, the wide variety of valve types requires careful selection based on specific working conditions. Improper selection can severely impact pipeline performance. During routine pipeline inspections, valve examination must be prioritized to ensure the efficiency and safety of the natural gas pressure network.
1. Factors Affecting Valve Operation in Pipelines
During actual operations, natural gas often carries impurities such as soil particles, sediment, and even construction debris, which are introduced during production and construction processes. These impurities threaten valve safety. Environmental factors, such as high temperature or humidity, also accelerate valve corrosion, leading to structural damage and functional failure.
2. Significance of Valve Maintenance
Valves play a vital role in natural gas pipeline networks. Failures can result in significant economic losses. As critical equipment for energy transmission, the safety of long-distance pipelines is paramount. Therefore, regular inspection and maintenance of valves are essential to identify potential failures and mitigate risks.
3. Causes of Valve Failures
3.1 Substandard Valve Quality
Valve failures due to poor manufacturing quality are common. With the rapid growth of China’s oil and gas industry, the market for long-distance pipelines has expanded, leading some manufacturers to compromise quality to reduce costs. Strict quality control for diverse valve types increases production costs, incentivizing substandard products. While inferior valves may not fail immediately, prolonged exposure to corrosive fluids and variable operating conditions accelerates wear, leakage, and failure.
3.2 Improper Valve Installation
Valve installation in natural gas pipelines requires adherence to industry standards and skilled technicians. However, errors due to insufficient technical expertise or negligence, such as incorrect valve selection or improper installation, are frequent. Environmental factors (e.g., temperature, humidity) further exacerbate valve stress and corrosion, compromising safety.
3.3 Nonstandard Valve Operation
Operator errors during valve adjustment—such as improper sealing, incorrect sequence of operations, or failure to inspect valve status—can lead to abnormal pressure fluctuations, system instability, and even major accidents.
3.4 Delayed Valve Maintenance
Regular inspections are critical for identifying valve defects. Common methods include pressure testing and defect detection equipment. Neglecting maintenance, especially in environments with oil or debris buildup, can render valves inoperable and trigger failures.
4. Measures to Address Valve Failures
4.1 Improving Valve Quality
Valve selection must comply with national standards. Suppliers must be rigorously vetted, and contracts should specify quality requirements and accountability. Purchased valves must undergo testing for strength, fatigue life, and pressure tolerance.
4.2 Standardizing Installation Procedures
Installation must follow national standards and be performed by qualified technicians. Pre-installation checks of valve models and environmental adaptability (e.g., temperature, humidity) are critical. Mitigation measures, such as temperature control or anti-corrosion treatments, should be applied based on environmental conditions.
4.3 Implementing Standardized Valve Operations
Operators must adhere to strict protocols and receive regular training. Post-operation inspections are necessary to confirm valve functionality and address issues promptly.
4.4 Enhancing Regular Maintenance
Scheduled inspections of valve status, pressure, and structural integrity are essential. Cleaning of debris and oil residues, combined with advanced defect detection technologies and real-time monitoring systems, ensures early fault identification.
4.5 Installing Safety Protections
Safety devices, such as fire prevention systems, should be installed near valves to minimize accident risks. Emergency protocols must be established for rapid response to leaks or fires.
5. Valve Maintenance Strategies
5.1 Using Qualified Materials
Valve materials must meet anti-corrosion standards while balancing cost-effectiveness. Selection should consider the pipeline’s operational environment.
5.2 Lubricating Rotating Components
Regular lubrication of rotating parts (e.g., stems, gears) reduces friction and wear. Loss of lubrication due to environmental factors must be monitored and addressed.
5.3 Controlled Grease Injection
Grease injection prevents valve wear, but improper quantities can cause inefficiency or waste. Injection volumes must align with operational requirements and pipeline conditions.
5.4 Reinforcement and Static Testing
Valves should undergo static leakage tests post-reinforcement. Over-tightening during installation must be avoided to prevent sealant loss.
Conclusion
Valves are critical to the safety of long-distance natural gas transmission pipelines. Comprehensive strategies—including quality control, standardized installation, operator training, proactive maintenance, and safety measures—are essential to minimize failures and ensure reliable energy supply.
Reference
Chemical Engineering Management (Journal), Issue 06, February 2025, Authors: Sun Li, Chen Lilong
