SF6 gas, with its superior insulation and arc-quenching properties, serves as the core medium for high-voltage switchgear (GIS, circuit breakers, etc.). Pressure parameters directly determine equipment operational safety and are the key basis for detecting gas leaks.
SF6 pressure is highly sensitive to temperature. The industry uniformly uses 20°C as the standard temperature for pressure conversion to eliminate environmental interference.
Rated pressure must match the equipment voltage level: approximately 0.4–0.5 MPa for 110kV GIS and approximately 0.5–0.6 MPa for 220kV GIS. Operating pressure must not fall below 80% of the rated value; otherwise, immediate gas replenishment and leak detection are required.
For routine SF6 pressure checks, you can use a portable pressure gauge, but for continuous, real-time monitoring in switchgear cabinets, we recommend installing a dedicated SF6 gas density monitor. These devices offer dual-alarm contacts, hermetic sealing, and compatibility with RMU and GIS systems, ensuring reliable protection against gas leaks and low-density conditions.
Step 1: Visual Inspection and Condition Verification. Remove the pressure gauge cover, clean any contaminants from the connection points, inspect the gasket for damage, and ensure all fittings are secure. Confirm the equipment is powered off and in a safe state. Review historical pressure records to identify the rated value.
Step 2: Proper Connection and Measurement. Connect the pressure gauge to the gas sampling port using a dedicated connector. Seal the joint with raw rubber tape. Slowly open the valve to purge air. Once readings stabilize, simultaneously record ambient temperature and measured pressure, verifying consistency with the density relay display.
Step 3: Data Conversion and Evaluation. Perform temperature compensation using the calibrator to convert measured values to standard pressure at 20°C. Normal operation is confirmed when standard pressure falls within the rated range and the daily average decrease is ≤0.005 MPa. If pressure drops below 80% of the rated value or exhibits abnormal decline, initiate leak detection immediately.
Xizi Energy is a Barometer manufacturer in China, specializing in precision barometers designed for medium and high voltage switchgear, SF6 load break switches, and gas‑insulated equipment.
Professional Medium & High Voltage Electrical Equipment Manufacturer
