Safety | Linde Gas Benelux

What is pressure?
Pressure is a force acting on an area which is caused by the compounds of the particles or by the weight that is placed on a surface. The pressure in a cylinder has a gas pressure of 1,013 bar, and because of this there is a pressure equilibrium with the air around the cylinder.

What is meant by vapour pressure?
Above any liquid surface, there is a vapour pressure, because particles detach from the surface of the liquid due to their own momentum. The pressure which is thereby brought about depends exclusively on the temperature of the fluid. The vapour pressure curve shows the dependence between the vapour pressure and the temperature of the fluid. The temperature that is required to generate a vapour pressure of 1 bar above the liquid is the boiling point of a substance.

What effect does temperature have on gas?
In addition to the pressure, the temperature has an influence on the gas. Under heating the gas expands, just as is the case with solid materials. An iron rod expands under heating and shrinks when it cools. With an increase in temperature the gas particles will move more rapidly. Because the speed increases, the particles collide more frequently with each other and with the wall of the package. The pressure in the cylinder thus increases as the temperature increases. For the sale of gases, we start from a content calculation on the basis of a temperature of 15 °C. On this 200 bar of content of pure gases is calculated.

What about liquefying gases?
Any gas can be liquefied by cooling back to the pressure corresponding to the boiling point. However, it is a requirement that this is below the so-called "critical temperature", because above it is not possible to liquefy. A distinction is drawn between "pressurised liquefied" gases, which can be liquefied by increasing the pressure at ambient temperature (e.g., propane or carbon dioxide), and "cryogenic liquid" gases (e.g., oxygen or nitrogen).

How much gas is in a cylinder?
The space that a specific amount of gas takes up decreases as the pressure increases. Therefore, the greater the pressure in the cylinder, the more gas there is in it. It follows from this that: the amount of gas in a gas cylinder is determined by the volume of the bottle and the pressure which the gas is under in the bottle. For most gases, the following applies: Gas content of a gas bottle = volume of the cylinder x pressure in the bottle.

Example:
In a steel cylinder of 50 litres water capacity filled at 200 bar there are 200 x 50 = 10,000 litres of gas or 10 m3 of gas.

You can check how much gas there is in a cylinder if you know the size of the cylinder and the filling pressure. This is true only for compressed gases, but not liquefied or dissolved gases, for which the content of the bottle can only be determined by weighing.

The driver must follow special rules when he comes to make the delivery, how can I ensure that?
You can inform us about the guidelines for our drivers via the online contact form. We will ensure that the drivers are informed by an instruction and a message on their delivery list.