GB/T 24591 Seamless Steel Tubes For High Pressure Feedwater Heater

High-pressure feedwater heaters are crucial components in power generation plants, enhancing the efficiency of the steam cycle. GB/T 24591 provides the standard for seamless steel tubes used specifically for these applications in China. This article explores the material properties, specifications, key features, chemical composition, mechanical properties, steel grades, application, and possible alternative grades specified under GB/T 24591.

Material

Seamless steel tubes governed by the GB/T 24591 standard are typically made from carbon steel and alloy steel, designed to endure high pressure and temperature conditions characteristic of feedwater heaters. These materials ensure structural integrity and longevity in demanding environments.

Specification

Seamless steel tubes under the GB/T 24591 standard exhibit the following specifications:

• Outside Diameter: Ranges from 10.0 mm to 426 mm.
• Wall Thickness: Ranges from 1.0 mm to 100 mm.
• Length: Customizable as per requirements, extending up to 12 meters.
• Process: Hot rolled or cold drawn, depending on size and desired surface finish.

Key Features

• High Temperature Resistance: Capable of performing efficiently under extreme heat conditions.
• High Pressure Endurance: Designed to withstand significant internal pressures.
• Corrosion Resistance: A quality particularly important given the exposure to water and steam, often with additives.
• Durability: Ensures long service life and reliability.
• Precision: Tight dimensional tolerances and smooth surface finish.

Chemical Composition

The chemical composition of these steel tubes affects their mechanical properties and performance. Below is a table detailing the standard elements and their typical percentage ranges.

Mechanical Properties

Mechanical properties dictate the performance of the tubes under stress. Below is a table summarizing the key mechanical properties.

Steel Grade

GB/T 24591 includes several grades, each tailored to specific performance needs. Common grades used include:

• 20G
• 15MoG
• 12Cr1MoVG

These grades are selected based on the balance of toughness, strength, and temperature thresholds required for specific applications.

Application

Seamless steel tubes outlined in GB/T 24591 are primarily used in high-pressure feedwater heaters to:

• Improve thermal efficiency in power plants.
• Preheat feedwater before it enters the steam generator.
• Reduce fuel consumption by recycling heat within the system.

Possible Alternative Grades

When GB/T 24591 grades are unavailable or unsuitable, the following alternative grades may be considered, subject to compatibility and regulatory approvals:

• ASTM A192
• EN 10216-2 (P235GH, P265GH)
• JIS G3461