Views: 0 Author: J-VALVES Publish Time: 2025-01-13 Origin: Site
EN 1074-3 is a European standard that specifies the requirements for industrial valves, including ball valves, designed for low-temperature service. It covers aspects such as material selection, design, and testing to ensure the valves can operate reliably at temperatures as low as -196°C.
Low-Temperature Performance Testing
• Test Temperature Range: EN 1074-3 specifies a wide range of test temperatures, typically from -196°C to ambient temperatures, depending on the valve's intended service conditions.
• Test Medium: The standard allows the use of liquid nitrogen or helium gas as the cooling medium, depending on the specific temperature requirements.
• Sealing Performance: EN 1074-3 requires that ball valves demonstrate zero leakage under low-temperature conditions. This is tested using helium gas at a specified pressure to detect any potential leaks.
• Operational Testing: The valves must undergo multiple cycles of opening and closing at low temperatures to ensure smooth operation and to measure the required operating forces.
GB/T 24925 is a Chinese national standard that specifies the technical conditions for low-temperature gate valves. It aims to ensure that these valves can operate safely and reliably in cryogenic environments, particularly in applications involving LNG and other cryogenic fluids.
Low-Temperature Performance Testing
• Test Temperature Range: GB/T 24925 specifies test temperatures ranging from -196°C to -29°C. However, the standard notes that temperatures above -46°C are not considered cryogenic and do not require low-temperature testing.
• Test Medium: Similar to EN 1074-3, GB/T 24925 allows the use of liquid nitrogen or helium gas as the cooling medium.
• Sealing Performance: GB/T 24925 requires that gate valves demonstrate minimal leakage under low-temperature conditions. The acceptable leakage rate is defined based on the valve size and type, with stricter requirements for soft-seated valves.
• Operational Testing: The valves must undergo multiple cycles of opening and closing at low temperatures to ensure smooth operation. The standard specifies the number of cycles and the required operating forces.
• EN 1074-3: Covers a wide range of low temperatures, including extremely cryogenic conditions down to -196°C.
• GB/T 24925: Focuses on temperatures from -196°C to -29°C, with specific notes on the distinction between cryogenic and non-cryogenic ranges.
Sealing Performance Requirements
• EN 1074-3: Requires zero leakage under low-temperature conditions, tested using helium gas.
• GB/T 24925: Allows for minimal leakage, with specific leakage rates defined for different valve sizes and types. Soft-seated valves have stricter requirements.
• EN 1074-3: Emphasizes multiple cycles of operation to ensure smooth valve movement and to measure operating forces.
• GB/T 24925: Specifies a similar approach but with detailed requirements on the number of cycles and the measurement of operating forces.
