In oil and gas, water treatment, power generation, and large-scale industrial transmission systems, large-diameter pipelines (DN300 and above) often bear the responsibility of transporting core media. These pipelines not only handle enormous flow rates but also have extremely high requirements for safety, stability, and long-term operating costs.
Among various valve types, gate valves are frequently the preferred choice for main pipelines. So, why do large-diameter systems tend to use gate valves? This article will provide a systematic analysis from multiple perspectives, including structural principles, engineering selection, industry applications, and solutions.
Before discussing valve selection, it’s essential to understand the operating characteristics of large-diameter pipelines:
1. High Flow Rate and Low Pressure Loss Requirements
DN300, DN600, and even larger pipelines are typically used for long-distance transport. If valves generate significant flow resistance, it will directly impact system efficiency and energy consumption.
2. Significantly Increased Valve Size and Torque
With larger diameters, valve weight, opening and closing torque, and installation space requirements increase significantly, placing higher demands on structural design.
3. Requirement for Long-Term Stable Operation
Large-diameter pipelines are often trunk lines; maintenance shutdowns are extremely costly. Therefore, valves must possess high reliability and long service life.
Under these operating conditions, gate valves, with their inherent structural advantages, have become the preferred choice for many engineering projects.
1. Straight-Through Flow Channel, Extremely Low Flow Resistance
In the fully open state, the gate of a gate valve completely exits the flow channel, forming a near-straight flow path. This design hardly changes the direction of medium flow, therefore:
Low pressure loss
High conveying efficiency
Significant energy-saving effect
This is especially important for long-distance oil and gas pipelines or municipal water systems.
2. Fully Open/Fully Closed Structure is More Suitable for Trunk Pipelines
Gate valves are typical shut-off valves, suitable for fully open or fully closed operation. Large-diameter main pipelines typically only require isolation functions, rather than frequent flow regulation. Therefore, the design concept of gate valves is highly compatible with actual needs.
3. Large sealing surface area, higher reliability
Large-diameter valves have stricter sealing requirements. Gate valves employ a double sealing surface design, maintaining stable sealing performance under high pressure or high temperature conditions, reducing the risk of leakage.
4. Uniform stress distribution, suitable for large-size structures
The up-and-down movement of the gate plate results in a more even stress distribution on the valve in large-diameter applications, making it easier to achieve stable sealing compared to rotary valves.
Comparison with ball valves: Ball valves offer strong sealing performance, but their weight and cost increase significantly in ultra-large diameter applications; they also require higher torque, increasing the cost of the actuator; therefore, for diameters above DN600, gate valves are often more economical.
Compared to butterfly valves: Butterfly valves are lightweight and suitable for low-pressure, large-diameter applications; however, gate valves are more reliable in high-sealing or high-pressure scenarios.
Compared to globe valves: Globe valves have higher flow resistance and are not suitable for long-distance transport systems.
Overall, gate valves have significant advantages in terms of low pressure loss, high sealing performance, and long service life.
1. Oil and Gas Industry
Oil and gas transmission pipelines typically use API standard gate valves:
Suitable for high-pressure, high-safety environments
Can be configured with pneumatic or electric actuators for remote control
Common standards include API 600 and API 6D
2. Water Treatment and Municipal Engineering
In water supply, drainage, and sewage systems:
Rising stem gate valves facilitate observation of opening degree
Low flow resistance, beneficial for large flow rates
Simple maintenance, suitable for long-term operation
3. Power and Energy Industry
Alloy steel gate valves are commonly used in steam and cooling water systems:
High temperature and high pressure resistance
Suitable for main steam or circulating water pipelines
Correct selection is crucial to ensuring long-term stable valve operation. It is recommended to focus on the following parameters:
1. Pressure Rating and Diameter
PN16, PN25, Class150, Class300, etc., must match the system
Too high or too low will affect cost and safety
2. Valve Body Material Selection
Carbon Steel: Conventional industrial systems
Stainless Steel: Corrosive media
Alloy Steel: High temperature and high pressure conditions
3. Rising Stem vs. Non-rising Stem Structure
Rising Stem Gate Valve: Easy to observe opening, suitable for water treatment
Non-rising Stem Gate Valve: Compact structure, suitable for space-constrained environments
4. Actuation Method
Manual: Simple maintenance, low cost
Pneumatic: Suitable for automated systems
Electric: Strong remote control capability
In large-diameter applications, materials and sealing design directly determine valve life:
Metal sealing structures are suitable for high temperature and high wear conditions
Stainless steel or alloy steel can improve corrosion resistance
Fireproof design and low-leakage structure are important requirements in the oil and gas industry
Through reasonable material matching, maintenance frequency and operational risks can be significantly reduced.
In actual engineering projects, valves are not just single products, but a complete system configuration. WEIZIDOM offers customers:
⭐ A comprehensive product line of large-diameter gate valves
⭐ API and industry standard solutions
⭐ Complete valve and actuator supply packages
⭐ Operating condition analysis and professional selection support
⭐ Stable delivery and project experience guarantee
By combining standardized products with customization capabilities, we help customers achieve the optimal balance between performance and cost.
In summary, the core reasons why gate valves are the preferred choice for large-diameter pipelines are: low flow resistance, suitability for long-distance transportation, reliable sealing, high safety, mature structure, low maintenance costs, and adaptability to complex operating conditions in multiple industries. In oil and gas, water treatment, and energy systems, the correct selection of large-diameter gate valves can not only improve system stability but also significantly reduce total lifecycle costs.
