LPG Characteristics

LPG Characteristics

These are the most important characteristics of the LPG.


LPG supplied to consumers has been stanched with special additives (mercaptans) carrying a characteristic unpleasant odour so as to be detected in case of leaks.


LPG is stored in liquid form in cylinders. In a filled cylinder, an 80% approximately of the internal volume (lower section) is occupied by liquefied gas while a 20% (upper) is occupied by LPG in gaseous form.
When we open the valve, a proportion of LPG in liquid form is evaporated by absorbing heat through the metal walls of the cylinder that comes in contact with the liquid.
However, the cylinder is cooled, when used. If LPG consumption exceeds the cylinder’s supply capacity, atmospheric moisture may condense on the walls of the cylinder itself and freeze it, thereby stopping LPG supply and therefore combustion.


LPG density is much higher than that of air and therefore it is considered a “heavy gas”. Therefore, in case of release to the atmosphere (e.g. in case of leakage), it tends to settle on the lower section of the area, unlike natural gas, which is lighter than air and tends to go up.


LPG that gets mixed with air in specific volume proportions (from 2% to 10% LPG to air), forms a flammable mixture, which is immediately inflamed even by a small spark (e.g. even by a spark of an electrical switch) or by the flame of a match or stove, even by the resistor of an electric stove or by the burning coal of a cigarette.


LPG is not toxic, but causes asphyxiation in high concentrations, so it is advisable to avoid inhalation. In liquid state, due to its very rapid evaporation, in case of contact with skin or eyes may cause injuries and burns. We must therefore necessarily avoid contact with it and strictly observe the following precautions:

  • Before purchasing and installing, as well as transferring of LPG appliances from one place to another, advice/assessment shall be necessary by a certified installer to check whether these devices are appropriate and capable to operate without problems in the position intended to be placed.
  • In case the appliances are not suitable, they must undergo alteration work. Hence we can avoid damage that could incur safety hazards. This work should be performed only by qualified technicians or technical service centres.
  • The safety, control and automatic adjustment mechanisms, installed on each device, must not be modified, except by the manufacturer of the device and on their own responsibility.


When referring to LPG, we must as well respect certain strict regulations. Protection and safety requires that the following regulations shall be observed by anyone involved:

  • The network of LPG should follow the technical regulations laid down by Legislation, depending on the category and type of installation.
  • The equipment to be used (boiler, water heater, kitchen, etc.), must meet the construction prerequisites set by the Law and the applicable Technical Regulations.
  • The maintenance of equipment should be performed in accordance with applicable technical regulations.


European Directive 90/396/CE specifies that LPG appliances should be made in accordance with it.
To obtain the CE label marking right, manufacturers will have to follow the safety regulations set by the European Directive 90/396/CE .


  • COMPLETENESS OF INSTALLATION – LPG fuel supplying facilities must always be in perfect condition (there should be no LPG leaks).
  • AERATION – Premises where devices are installed should be properly ventilated so that the air necessary for combustion shall freely flow.
  • INFILTRATION – Spaces where, devices that release combustion products to the environment are installed, must be properly ventilated so that air is renewed.
  • EXHAUST – The appliances that must remove fumes produced by combustion outside, must be connected with exhaust systems, such as chimneys, flues, etc., which will be working safely.
  • FLAME CONTROL MECHANISMS – All devices must carry safety mechanisms in order to interrupt LPG supply in case the device stops working.


For LPG powered appliances to be absolutely safe, they should periodically be inspected and maintained in accordance with manufacturer’s instructions, as described in the device manual. Boilers must be checked and serviced every year before the heating season.
Proper use (as provided in the instruction manual) ensures that:

  • Device is kept functional.
  • Significant savings are obtained in consumption.
  • Contribution is made to keep the environment clean, reducing the emission of pollutants.

For regular inspection and maintenance, it is necessary to consult a licensed technician.


Installation, extension, modification and maintenance of LPG installations, containing LPG tanks, should be performed only by certified technicians, qualified with the necessary technical and professional skills.
Additionally, the installer must determine whether the place where installation is to be made meets the necessary requirements for aeration, ventilation, proper exhaust as well as installation of devices based on their characteristics


Never attempt to locate a possible LPG leak using an open flame, instead always use soap and water solution or specific leak detection spray!

If you detect an LPG leak, then:

  • DO NOT attempt to turn on or turn off appliances and lights, the spark could ignite the free LPG!
  • DO NOT use your cell phone.
  • Close the nearest LPG supply valve and then the cylinder or the tank valve.
  • Extinguish all possible sources of ignition.
  • Remove all persons who may be endangered and keep them at a safe distance until elimination of the risk.
  • If the leak is indoors, open windows and doors for quick ventilation.
  • If the leak is from the tank, open the sprinkler of the tank and let it spray water to help dispersal.


For each intervention, conversion, extension and maintenance of LPG installations, as well as for the installation and maintenance of equipment, you must always consult licensed technicians. THE ” DO IT YOURSELF” APPROACH IS STRICTLY PROHIBITED!


What are the “necessary conditions” that must be observed by consumers, for the protection and safety?

You are required to observe the following, which may prove important for your safety.

  • Switch off the meter valve or LPG supply hose inlet valve in the distribution area or in the cylinder area, when the devices are not operating.
  • Always close the valve, during your absence from home, even if you will be away for a short time.
  • To ignite LPG appliances, you are advised to follow this procedure:
  1. Light a match.
  2. Approach the match to the device.Always close the valve, during your absence from home, even if you will be away for a short time.
  3. Open LPG switch on the device.

If you follow this procedure in reverse order, it is possible that, after opening the LPG supply switch, something may distract you (e.g. a ringing phone or doorbell) so afterwards, when you fire this switch with your match, serious consequences might occur.

  • Do not leave the kitchen while food is being cooked on the stove.
  • Avoid overfilling of pans. Overflow of boiling fluids can cause the extinguishing of the flame and hence serious accidents.

Note: There are currently commercial cookers equipped with safety mechanisms, which, in case of accidental extinguishing of the flame, interrupt the LPG supply. Although their cost is slightly higher than the rest, we would advise you to buy one of these because they can significantly contribute to your safety.