ISO 7382:2023

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).