99.9995% (5.5N) Imported High-Purity Helium Gas

Product Name: High Purity Helium

English Name: Helium
Purity: 99.9995%
Packaging Specification: 47L DOT Steel Cylinder
Origin: Imported from the United States
Pressure: Approximately 16.5 MPa
Filling Volume: Approximately 7 m³
Molecular Formula: He

Quality Indicators Reference

Physical and Chemical Properties of High Purity Helium

At room temperature and atmospheric pressure, helium is a colorless, odorless gas. Its volume fraction in dry air is 5.24×10⁻⁶. It is the substance with the lowest critical temperature discovered by humans. It appears deep yellow during low-pressure discharge.

Helium cannot be solidified merely by cooling saturated liquid to absolute zero. Solidifying helium requires applying corresponding pressure. At 2.173 K, helium transforms more or less from a normal liquid into a fluid with unique properties. The liquid above 2.173 K is called helium I. The liquid below this temperature is called helium II. Helium II is a superfluid. It has zero entropy, extremely high thermal conductivity, and almost zero viscosity.

Due to the low temperature of liquid helium, cooling certain metals or metal compounds with liquid helium causes their electrical resistance to completely disappear. This phenomenon is called superconductivity, and this temperature is known as the critical temperature.

Because helium transmits sound nearly three times faster than air, people who inhale helium speak with a higher frequency. This interesting phenomenon makes their voices sound high-pitched and squeaky, much like classic cartoon characters.

Helium is a monatomic gas with inert chemical properties. Helium generally does not form compounds. Under excitation in low-pressure discharge tubes, it can form ions and molecules such as He⁺₂ and HeH.

Applications of High Purity Helium

High purity helium is widely used in military industry, scientific research, petrochemicals, refrigeration, medical fields, semiconductors, pipeline leak detection, superconducting experiments, metal manufacturing, high-precision welding, optoelectronic product production, and more.
1. High purity helium is used as a shielding gas: Due to its inert chemical properties, helium is commonly used as a shielding gas for welding metals such as magnesium, zirconium, aluminum, and titanium.
2. High purity helium can be used as a pressurizing gas for high-vacuum devices, nuclear reactors, and spacecraft to transport liquid hydrogen, liquid oxygen, and other liquid propellants. High purity helium is also used as a cleaning agent in nuclear reactors.
3. High purity helium has significant applications in superconducting technology for transportation, such as maglev trains, and in medical fields for MRI equipment. Utilizing the low boiling point of liquid helium at -268.9°C, it is used for ultra-low temperature cooling. Ultra-low temperature cooling technology is widely applied in fields like superconductivity, where superconducting materials require low temperatures (around 100 K) to exhibit superconducting properties. In most cases, only liquid helium can conveniently achieve such extreme low temperatures.
4. In gas chromatography analysis, high purity helium is often used as a carrier gas. Due to its high permeability and non-flammability, high purity helium is also used for vacuum leak detection, such as in helium mass spectrometers.
5. Industrial helium is widely used for balloon inflation: Since helium density is much lower than air (air density is 1.29 kg/m³, helium density is 0.1786 kg/m³) and it is chemically inert, it is safer than hydrogen (hydrogen can burn in air and may cause accidents). Helium is commonly used as the filling gas for airships or advertising balloons.
6. In mixed breathing gases for marine development and as a filling gas for gas thermometers.