Overview
EN ISO 6368:2021 - Petroleum, petrochemical and natural gas industries - Dry gas sealing systems for axial, centrifugal, and rotary screw compressors and expanders - provides guidance for the selection, specification and application of dry gas sealing systems used on compressors and expanders. Intended primarily for oil refineries, it is also applicable to petrochemical plants, gas plants, LNG facilities and upstream production sites. This European adoption of ISO 6368:2021 supplements API Std 692 (1st ed., 2018) by specifying exceptions and additional requirements tailored to ISO/CEN practice.
Key topics and requirements
- Scope and applicability
- Covers dry gas sealing systems for axial, centrifugal and rotary screw compressors and expanders described in ISO 10439 and ISO 10440 (parts).
- Excludes other shaft seals (clearance seals, restrictive ring seals, oil seals).
- Standards alignment
- Acts as a supplement to API Std 692; where API clauses are referenced, EN ISO 6368 specifies ISO equivalents (for example ISO 10439, ISO 10440‑1/2) and other normative references.
- Materials and metallurgy
- Requirements for sleeves, retainers, housings and carriers reference ISO materials standards (e.g., ISO 17945 as a substitute where applicable).
- Module DD3 - double seal differential control
- Provides supplementary requirements for double-seal arrangements and differential pressure control between sealing chambers.
- Auxiliaries and system components
- Guidance on coolers, pressure-relieving devices, valves, heat exchangers and system diagrams used in dry gas seal systems. ISO standards such as ISO 13706, ISO 16812 and ISO 23251 are cited as normative references.
- Safety and installation
- Emphasizes selection based on risks and site circumstances, and includes references to pressure-relief and safety device standards.
Applications and users
EN ISO 6368:2021 is useful for:
- Mechanical and rotating-equipment engineers specifying or designing compressor seal systems
- Procurement and vendor evaluation teams assessing dry gas seal packages
- Maintenance and reliability engineers managing seal life, monitoring and replacement programs
- Process safety and inspection specialists ensuring compliance with pressure-relieving and material requirements
- OEMs of axial, centrifugal and rotary screw compressors and seal-system manufacturers
Practical applications include retrofits, new compressor train specification, seal system selection for LNG skids, refinery and petrochemical rotating equipment, and standardizing purchase requirements across multi-site operations.
Related standards
Using EN ISO 6368:2021 helps ensure consistent, safer and more reliable dry gas seal system selection and integration across petroleum, petrochemical and natural gas facilities.