IEC 62271-204:2022

Overview

IEC 62271-204:2022 - "High‑voltage switchgear and controlgear – Part 204: Rigid gas‑insulated transmission lines for rated voltage above 52 kV" is the international standard that defines technical requirements for rigid gas‑insulated transmission lines (GIL) used on AC systems with rated voltages above 52 kV and service frequencies up to 60 Hz. This second edition (2022) replaces the 2011 edition, aligns voltage ratings and test voltages with IEC 62271‑1:2017, and adds guidance on welds on pressurized parts and gas tightness.

Key topics and technical requirements

The standard covers design, testing and operational aspects of rigid GIL systems. Major technical topics include:

• Scope and service conditions: normal and special conditions (altitude, temperature, pollution, vibration, wind, tunnel or buried installations).
• Ratings: rated voltage, insulation levels, continuous and short‑circuit current ratings, auxiliary supply requirements and rated pressure for gas systems.
• Design and construction: requirements for gases and liquids, earthing, enclosures, partitions, filling levels, pressure/level indication, corrosion protection and fire hazard mitigation.
• Gas tightness and pressure systems: controlled, closed and sealed pressure systems; pressure relief and limitation of maximum filling pressure.
• Operation and safety: position indication, locking devices, protection against electric shock, EMC and X‑ray emission considerations.
• Mechanical aspects: supporting structures, thermal expansion compensation, vibration and impact resistance.
• Type tests and dielectric testing: mandatory and special type tests, dielectric/wet tests and reporting requirements to verify conformity.

Practical applications

• Specification, design and procurement of rigid GIL for overhead, tunnel, buried or open‑air high‑voltage transmission projects.
• Manufacturer design validation, quality control and type testing of gas‑insulated transmission components.
• Installation, commissioning and maintenance procedures for utilities and EPC contractors to ensure gas tightness, pressure safety and correct earthing.
• Safety and compliance checks for inspectors and certification bodies assessing conformity with international high‑voltage equipment standards.

Who should use IEC 62271-204:2022

• Manufacturers of rigid gas‑insulated transmission lines (GIL) and components
• Power utilities, transmission system operators and grid planners
• Design and consulting engineers specifying high‑voltage transmission solutions
• Test laboratories and certifying agencies performing type and routine tests
• Procurement teams and regulators ensuring equipment interoperability and safety

Related standards

• IEC 62271‑1 (Common specifications for AC switchgear and controlgear) - alignment of ratings and test voltages
• IEC 62271‑203 and other parts of the IEC 62271 series covering gas‑insulated switchgear and associated topics

Using IEC 62271‑204:2022 helps ensure reliable, safe and interoperable high‑voltage GIL systems that meet internationally accepted requirements for performance, testing and installation.