The pure gas offer includes a broad choice of different gas in various purities (see the list below) and packaging. The list of mentioned products contains the most important basic parameters of selected gases. Should you not find the gas you are interested in, please contact us.
Specialty gases are produced in the production plant of Linde Gas in the Czech Republic, or they are supplied from other Linde plants from all over the world. The specialty gas purchase is carried out through the large network of Linde Gas sales places.
Information for the users
Gas purity
The minimal purity concept determines the amount of specified impurities which are typical for the given gas type. These limit values of impurity contents must not be exceeded.
Each cylinder filled with a high-purity gas is delivered together with a certificate that confirms its content adherence to the limit values of individual impurity contents. The relevant information is stated at the gas purity grade. It does not relate to gases in small vessels. Very often, the delivered gas has a higher than guaranteed purity. Although such situation comes quite often, this does not mean that the better-than-guaranteed parameters will be adhered to in each delivery.
Purity grade
The gas purity determines the minimal pure gas content that is expressed in ideal volume percents of gas. The information about the purity grade is usually stated in the so-called “system of nines” - as two digits separated by a dot. The first digit means the number of nines in the percentual description; the second nine is the value of the last place.
Examples:
Butane 2.5 represents the purity of 99.5 %
Argon 6.0 represents the purity of 99.9999 %.
For some gases, the purity grade is determined by their application type, e.g. helium ECD or carbon dioxide SFC/SFE. In other cases, the information about the purity may be stated as absence of a specified unwanted impurity, e.g. “nitrogen without CO” or “synthetic air without hydrocarbons (without C nH m)”.Impurity specification
Impurities are specified according to their types and concentrations. For pure gases, impurities are stated in the sheet and in the relevant certificate. Linde Gas guarantees the adherence to the specified impurity amount and type.
Volume parameters
Percentual values that are stated as purity or impurity concentration are molar percents (ideal volume percents). Very small values are stated in ppm or ppb (ppm = 1 share in one million = 10-4%; 1 ppb = 1 share in one billion).
1,000,000 ppm |
= |
100% mol |
1 ppm |
= |
0.0001% mol |
1,000,000,000 ppb |
= |
100% mol |
1 ppb |
= |
10-7% mol |
Quantitative parameters
Unless otherwise stated, the following conventions hold: 1 m3 of gas is an amount which fills one cube with one-meter edge by temperature of 15°C and pressure of 1 bar. 1 litre of gas is one thousandth of gas volume which was defined in this way. Unless otherwise stated, the pressure in bars represents the absolute pressure. In case of gases with critical temperature Tk= 10°C, the amount is stated in kilograms.