IntroductionCategoryDetailsPhysical Properties– Molecular Weight: 4.003 g/mol– Density (Gas): 0
E-postadress: info@standard-groups.com
| Category | Details |
|---|---|
| Physical Properties | – Molecular Weight: 4.003 g/mol |
| – Density (Gas): 0.1785 kg/m³ (0°C, 1 atm); (Liquid): 125 kg/m³ (-269°C) | |
| – Boiling Point: -268.93°C (4.2 K) | |
| – Critical Temperature: -267.96°C (5.19 K) | |
| – Thermal Conductivity: 0.1513 W/m·K (2.7× air) | |
| Technical Specifications | – Purity: 99.995% (4.6 grade, industrial); 99.9995% (5.0 grade, research) |
| – Impurity Limits: O₂ ≤ 0.5 ppm, N₂ ≤ 1 ppm, H₂O ≤ 0.2 ppm (5.0 grade) | |
| – Pressure: 137 bar (20°C, liquid in cylinders); 1 bar (vapor at 25°C) | |
| – Cylinder Sizes: 10L, 50L, 100L (compressed gas); 50L–10.000L (liquid) | |
| – Valve Types: CGA 580 (US), DIN 477 (EU), and JIS B 8241 (Japan) | |
| – Flow Rate: 0.1–50 SLPM (standard liters per minute) | |
| – Purity Analysis: GC-TCD (Gas Chromatography with Thermal Conductivity Detector) | |
| Key Applications | – Cryogenics: Cooling superconducting magnets (MRI, NMR) |
| – Welding: Shielding gas for aluminum/stainless steel (He/Ar mixtures) | |
| – Leak Detection: Pressurized systems (helium mass spectrometry) | |
| – Aerospace: Pressurizing rocket fuel tanks | |
| – Breathing Mixtures: Deep-sea diving (He/O₂ blends) | |
| Safety Data | – CAS No.: 7440-59-7 |
| – UN Number: 1046 (compressed); 1963 (liquid) | |
| – NFPA 704: Health 0. Flammability 0. Reactivity 0 (inert) | |
| – Asphyxiation Risk: Displaces oxygen in confined spaces; monitor O₂ levels (≥19.5%) | |
| – Cryogenic Hazard: Liquid He causes severe frostbite (use PPE: gloves, face shield) | |
| Storage & Handling | – Compressed Gas: Store upright in cool, well-ventilated areas (≤50°C); secure cylinders to prevent falls |
| – Liquid Helium: Use vacuum-insulated dewars; avoid spills (rapid vaporization) | |
| – Ventilation: Ensure airflow in enclosed spaces to prevent CO₂/He buildup | |
| Certifications | – ISO 7291: Gaseous purity standards |
| – ASTM D7673: Cryogenic liquid testing | |
| – OSHA 29 CFR 1910: Cryogenic liquids regulations | |
| Environmental Impact | – Non-Toxic & Inert: Minimal direct environmental impact |
| – Resource Scarcity: Non-renewable (extracted from natural gas); global shortage concerns | |
| – Recycling: Encouraged in MRI/NMR systems to mitigate supply risks | |
| Kvalitetskontroll | – Traceability: Lot-specific certificates of analysis (COA) |
| – Leak Testing: Helium mass spectrometry (≤1×10⁻⁹ atm·cm³/s) | |
| – Shelf Life: 24–36 months (certified stability when stored properly) |
Ansvarsfriskrivning: Ovanstående innehåll är endast för referens och kommunikation mellan branschinsider, och garanterar inte dess riktighet eller fullständighet. Enligt gällande lagar och förordningar och förordningar på denna webbplats ska enheter eller individer som köper relaterade artiklar erhålla giltiga kvalifikationer och kvalifikationsvillkor.
Företagstelefon
+86-21-6420 0566
Arbetstider
måndag till fredag
Mobiltelefon:
13816217984
E-post:
info@qinsun-lab.com
