Author: Site Editor Publish Time: 2026-05-20 Origin: Site
In the construction of petrochemical and chemical enterprises, valve systems play a pivotal role. They are crucial for controlling fluid flow, pressure, and temperature, ensuring the safe and efficient operation of the entire production process. This article will provide a detailed analysis of one-stop solutions for valve systems in these enterprises, covering valve selection, installation, maintenance, and intelligent upgrades.
Before selecting valves, it is essential to clearly define their functions, such as cutting off, regulating, preventing backflow, or throttling. Simultaneously, precise process parameters must be determined, including the physical and chemical properties of the medium (e.g., corrosiveness, viscosity, and solid content), design pressure, design temperature, and control methods (manual, electric, pneumatic, or hydraulic).
For instance, in a petrochemical plant's steam pipeline system, where the medium is high-temperature steam with a design pressure of 6.4 MPa and a design temperature of 450°C, and the control method is electric, a high-pressure globe valve with a hard alloy sealing surface and an electric actuator should be selected. This valve type can withstand high pressure and temperature while providing precise flow regulation through the electric actuator.
Different valve types have distinct structural characteristics and performance advantages, making them suitable for specific process requirements.
Gate Valves: These are widely used for cutting off media in steam, oil products, and pipelines containing granular solids. They offer low resistance when fully open and are available in rising-stem and non-rising-stem designs. For corrosive media environments, rising-stem gate valves are preferred, while non-rising-stem gate valves are suitable for low-pressure and non-corrosive media.
Ball Valves: Ideal for low-temperature, high-pressure, and high-viscosity media, as well as media containing suspended solid particles. They feature quick opening and closing, excellent sealing performance, and low fluid resistance. For large-diameter ball valves (DN ≥ 200 mm), worm gear transmission is recommended to reduce operating torque, while fixed-ball ball valves are more stable for high-pressure applications.
Globe Valves: Suitable for pipelines where pressure loss is not a critical concern, such as high-temperature and high-pressure steam pipelines with diameters less than 200 mm. They are also used for small-diameter valves like sampling valves, needle valves, and instrument valves. For toxic media, bellow-sealed globe valves should be chosen to ensure zero leakage.
Check Valves: Used to prevent backflow in clean media pipelines. The selection depends on the pipe diameter: lift check valves for DN ≤ 40 mm (horizontal installation only), swing check valves for DN 50–400 mm (horizontal or vertical installation, with vertical installation requiring bottom-up media flow), and buffer check valves for DN ≥ 450 mm.
The choice of end connection methods—threaded, flanged, or welded—depends on pipe diameter, pressure rating, and disassembly frequency.
Threaded Connections: Suitable for small-diameter valves (DN ≤ 50 mm) as larger diameters increase installation difficulty and the risk of seal failure under high pressure.
Flanged Connections: The most common choice in chemical plants, adaptable to all diameters and pressure ratings. They offer easy installation and disassembly but are bulkier and slightly more expensive than threaded connections.
Welded Connections: Preferred for high-temperature, high-pressure, and highly corrosive environments where long-term continuous operation with minimal maintenance is required, such as high-temperature steam mains and toxic media pipelines. However, they are difficult to disassemble and reinstall.
Before installation, conduct a thorough inspection of the valve, including cleaning the interior to remove debris, checking for end corrosion, and verifying that the valve is centered if it has positioning bolts. For large valves, develop a detailed lifting plan considering factors like bundling methods, hook placement, paint protection, tool and crane capacity requirements, stationing methods, and lifting paths.
Valve sealing tests are crucial for ensuring no leakage during operation. According to GB/T 13927-2022, these tests include:
Shell Test: Verifies the strength and sealing performance of the valve shell and seat.
Backseat Test: Checks the sealing performance at the connection between the valve drive and the stem.
Low-Pressure Sealing Test: Tests the sealing between the closing member and the seat using air or nitrogen as the medium at a pressure of 0.6 MPa or a specified value.
High-Pressure Sealing Test: Similar to the low-pressure test but uses water as the medium at 1.1 times the nominal pressure (PN) or the specified shell design pressure (PS).
Valve coating is vital for corrosion resistance and longevity. Protect valve ends and stems before sandblasting to prevent damage and ensure uniform coating adhesion. Use paint that meets project specifications regarding color, thickness, and adhesion. After painting, label valves with their type and tag number for easy identification during installation and maintenance. Additionally, protect the valve waterline surface during lifting to prevent scratches that could compromise sealing performance.
Regularly inspect valves for signs of wear, corrosion, or leakage. Clean valves to remove debris and buildup that could affect performance. For example, in a chemical plant's sulfuric acid pipeline, monthly inspections can detect early signs of corrosion on valve bodies and seals, allowing for timely replacement and preventing leaks.
Lubricate valve stems and moving parts to reduce friction and ensure smooth operation. Replace seals as needed to maintain sealing performance. For instance, in a high-pressure steam pipeline, the gland packing of a globe valve should be replaced every six months to prevent steam leakage.
Conduct performance tests, such as flow and pressure tests, to verify valve functionality. For critical valves, like safety valves in a reactor system, annual performance tests are essential to ensure they open at the set pressure and reseat properly.
Incorporating IoT sensors into valves enables real-time monitoring of parameters like pressure, temperature, and flow rate. For example, in a municipal water supply network, smart pressure-regulating valveswith IoT technology can reduce leakage rates by 18% through continuous monitoring and early warning of leaks.
Edge computing allows valves to process data locally, reducing latency and improving response times. In a flood control project, adaptive pressure-regulating valveswith edge computing can achieve dynamic pressure balancing in the pipeline network, enhancing flood control efficiency.
AI algorithms can analyze valve operation data to predict and diagnose faults. In a hydrogen refueling station, 70 MPa hydrogen refueling valves equipped with AI fault diagnosis modules can improve safety by detecting potential issues before they lead to failures.
A one-stop solution for valve systems in petrochemical and chemical enterprises involves careful valve selection based on process requirements, proper installation following strict standards, regular maintenance to prolong service life, and intelligent upgrades to enhance efficiency and safety. By implementing these measures, enterprises can ensure the reliable operation of their valve systems, contributing to the overall success of their production processes.If you want to build a petrochemical and chemical enterprise,but don't know how to start,you can consult us by banmy@bjafatech.com or +86-18611864848.We will provide you expertised and costomized solutions.And you can visit our website www.bjafatech.com to learn more about us.
