Overview
ISO 7382:2023 - Ethylene for industrial use - Sampling in the liquid and the gaseous phase - specifies procedures and precautions for drawing representative samples of ethylene in both the liquid phase (stored at about −100 °C) and the gaseous phase for subsequent analysis. The standard covers sampling apparatus examples (non‑closed and several closed systems), purging and filling procedures, safety requirements, maintenance, reporting and a diagrammatic sample disposal system (Annex A). ISO 7382:2023 replaces the 1986 edition and expands scope to include sampling for trace polar compounds.
Key topics and requirements
- Scope and purpose
- Sampling representative ethylene samples in liquid (cryogenic) and gas phases for analysis.
- Safety precautions
- Follow ISO 3165:1976 and applicable legal/statutory regulations.
- Ethylene properties noted: boiling point ≈ −103.9 °C, critical temperature 9.5 °C, critical pressure 5.04 MPa.
- Requirements: adequate ventilation, electrical grounding, thermal protection for operators (insulating gloves, goggles), pressure‑rated equipment and periodic pressure testing.
- Apparatus types
- Non‑closed sampling apparatus (open venting during purge/sample): typical components include sampling cylinder (tested at 34.5 MPa), dip pipe (fill to ~30% capacity), T‑union, passivated stainless‑steel connecting pipes and vent line.
- Closed sampling apparatus (no release of sample/vapour): multiple closed systems described, including variants with heated regulators and fully passivated configurations.
- Material & surface treatment: fluorocarbon‑lined or specially passivated sampling cylinders and stainless steel are recommended to avoid loss or reaction of trace polar compounds.
- Procedures
- Stepwise purge, fill and vent instructions to obtain representative samples without contamination or excessive vapor release.
- Avoid excessive purging to prevent icing and atmospheric pollution.
- Maintenance & reporting
- Guidance on regular maintenance of sampling apparatus and standardized sampling reports to document conditions and traceability.
- Sample disposal
- Annex A provides a diagrammatic system for safe disposal of unused liquefied or gaseous light olefin samples.
Applications
ISO 7382:2023 is intended for:
- Petrochemical and chemical plants producing, storing or distributing ethylene
- Laboratory analysts and QA/QC personnel performing composition and impurity analyses (including trace polar compounds)
- Sampling technicians, safety officers and regulatory compliance teams involved in cryogenic and pressurized gas sampling
- Engineering teams specifying sampling systems and procurement for cylinder and line materials
Keywords: ethylene sampling, liquid ethylene, gaseous ethylene, cryogenic sampling, closed sampling apparatus, non‑closed sampling, passivated sampling cylinder, sample disposal, ISO 7382:2023.
Related standards
- Normative reference: ISO 3165:1976 (Sampling of chemical products for industrial use - Safety in sampling)
- Applicable national regulations for pressure vessels, transportation of hazardous materials and environmental/safety legislation (as noted in ISO 7382:2023).