Gas cylinders or gas pipes do not reduce the risk of leaks. It is impossible to feel it quickly. But gas asphyxiation and house collapse after an explosion can happen suddenly. You have to be vigilant. Know how natural gas smells, why it leaks, and most importantly, how to detect gas leaks.
The main causes and locations of gas leaks
Sometimes a common household leak is enough to cause a powerful explosion. An explosive mixture is formed when the concentration of gas in the air reaches 5-15%. Even turning on a light in a room will act as a trigger under such circumstances.
Two types of gas are used in everyday life: natural gas, which is fed centrally through a main pipeline, and liquefied gas, which is stored in special cylinders. Very often it is gas cylinders that cause troubles. They explode if dropped, improperly stored and used.
Once in the air, methane reduces the oxygen available in the air. The result is that people in the gassed room suffer from oxygen deprivation leading to suffocation.
In addition to simple negligence and disregard for appliance operation, common causes of leaks include the following
- Refurbishment, unauthorised installation of gas boilers and cookers in inappropriate locations, without prior approval from specialists
- Illegal connection of appliances by individuals who do not have permits for such work
- Wear and tear on gas pipes
- Improperly executed welding, rupture of welded joints
- Corrosion damage to the walls of the pipeline
- Rupture and damage of hoses connecting the equipment to the pipeline
- Wiping of sealing materials on cocks and hoses; poor quality screw connections
- Faulty closing of the gas valve
- Extinguishing of the flame when the burner is switched on (caused by draught, water spillage, dirt on the construction)
- Burner malfunctions
How to check for gas leaks in your home
The smell of gas is familiar to everyone and difficult to confuse with other smells. If you smell gas:
- Try to reduce breathing (a high concentration of gas in the lungs may cause loss of consciousness)
- Open all the windows
- Do not operate any electrical appliances. Do not use fire (matches, lighters)
- Close the main valve on the gas pipe
- Call the gas leak detection company
An awake adult might respond to the smell. What to do when there are children, elderly people or at night, when most people are sleeping and it is difficult to smell gas? Gas leaks in such events will in most cases lead to tragedy.
When a room is filled with gas, fatalities from gas poisoning are common.
Therefore, you should not rely on checking the equipment by gas services, on your sense of smell and gut feeling. That is where the question arises – how to protect yourself from an explosion, suffocation from household gas. Special sensors are available to detect gas in living rooms.
Identifying and repairing leaks in good time is essential for the safe operation of gas appliances. If you notice any signs that signal a problem, it is advisable to call the gas service immediately.
There are several ways to check if there is a gas leak and if you should sound the alarm.
- Method 1 – by smell and hearing
- Method 2 – Check for leaks by feel
- Method 3 – testing with soapy water
- Method 4 – gas system pressure test
- Method 5 – Using sensors and a gas analyser
Method 1 – by smell and hearing
The main indication of a probable leak is a characteristic, specific smell in the room.
The gas itself, which is intended to be used for household purposes, is neutral in colour and odour. But to prevent accidents special substances – odorants – are added to it. It is these components that give the mixture an unpleasant odour that allows unmistakable detection of an excessive concentration of gas in the air.
If a pungent smell of rotten cabbage, rotten eggs or stale hay can be detected in the room, it means that there is a leak somewhere. It is often mistaken for the stench of spoilt food, oil and paint. However, if you suspect something is wrong, you should make sure there is no problem.
If you smell gas in a room, you should contact a professional or use additional inspection methods.
Another sign of leaks is a whistling sound that occurs in areas where there are leaks. In damaged areas, gas escapes in a strong jet with a whistling and hissing sound. This sound indicates an obvious, serious fault.
Method 2 – Check for leaks by feel
Although the gas is invisible, you can feel the gas escape to the touch. This can be done by running your hand along pipe joints, seams, flange connections. The mixture escaping can be felt as a jet of cold air.
As methane is colder than air, it slightly cools the skin when you perform a tactile test. To increase sensitivity, it is better to perform the manipulation with wet hands
The tactile method is only suitable for easily accessible areas where gas pipes are not covered by a kitchen appliance. In areas with limited access other methods of testing are used.
Method 3 – testing with soapy water
To confirm the fault and identify the problem area, a visual inspection of the pipes is carried out using a soapy solution to check for gas leaks.
A specially prepared foamy solution is applied with a thick brush or shaving brush to hoses, pipes and joints. It is recommended that valves and joints be particularly thoroughly cleaned.
After application, it is important to look carefully at each area that has been sprayed with the solution. If soap bubbles appear somewhere, this indicates gas escaping in that area.
Any shampoo, shaving foam, soap or washing powder will do. Dissolve it in water and whip it into a foam.
When checking external gas pipework outside the house, look for yellowing of vegetation, soil disturbance and frost formation. These are all signs of a possible leak.
Method 4 – gas system pressure test
In the following we will look at how to detect gas leaks in hard-to-reach places in the flat. The residual pressure test is ideal if it is inconvenient to wade through with soap and water and appliances. It allows you to check all connections, from the burners to the tap. It takes a few minutes to carry out the manipulation.
First you must open the burners and run the gas through them. Then turn them off and close the gas valve on the pipe. In this way you will have a residue in the system that has not yet been completely burned.
Then, after waiting 1 to 3 minutes, proceed as follows
- remove the lid from any burner
- a lighted match is placed in the middle of the burner
- Open the burner switch sharply to the maximum position
If there are no leaks, the gas remaining in the system will burn out. Otherwise, the residue will have time to escape through the damaged area and nothing will happen when the fire is brought to the burner.
Method 5 – Using sensors and a gas analyser
The safest, most reliable and practical way to detect a leak is to install a gas detector in the room. This is a special device equipped with sensors that detect methane and carbon monoxide in the air.
If the concentration of these substances is exceeded, light and sound signals are emitted, alerting the occupant to the problem. They are installed at a minimum distance of 30 centimetres from the ceiling.
There are different types of sensors with different designs, connection methods, autonomy and operating principles. The range includes simple models and multifunctional devices that work with several types of substances.
Wired sensors are mains-powered, wireless sensors are battery-powered. The former are easier to maintain and do not need battery monitoring. The latter are mobile and do not depend on an electrical power supply.
The main difference between the models is the method of determining the concentration of fuel, according to which there are three types of gas analyzers:
Catalytic gas analysers are more commonly used in industrial applications and can be powered or battery operated. They are equipped with a chamber in which a small amount of gas burns and even starts when its concentration is slightly higher than the ambient temperature. This changes the temperature of the coil, to which the electronic chip reacts by triggering a notification.
Semiconductor sensors are affordable and suitable for domestic use. They are only mains powered and have minimal power consumption.
They are equipped with a semiconductor wafer coated with a specific chemical compound. If gas hits the plate, its electrical resistance changes. This is detected by an electronic circuit which triggers an alarm
The infrared models are the most reliable and convenient. They are battery and mains powered. They have the advantage of instant response, minimum false alarms and economical power consumption.
Infra-red detectors detect the presence of gas particles by means of radiation and can easily detect the difference in light scattering. When impurities are detected, a light and sound alarm is triggered.
In addition to stationary equipment that continuously analyses the gas environment, there are portable gas analysers that are used to locate leaks in pipes or to measure gas concentrations for a short time.
Preventive measures package
To prevent gas leaks, the associated extreme situations and other undesirable problems, a number of preventive measures can be taken.
Rules that must be observed by all household consumers
- When leaving home, turn off all gas appliances and turn off gas supply valves
- Do not connect or repair the equipment yourself or use a third party to do so and do not make any modifications to the equipment
- check that the ventilation system is working properly, have the draft checked by a gas company and ventilate the premises regularly
- remember the correct sequence of starting appliances: first light the match and then open the gas
- Do not leave switched on equipment unattended and do not allow children or persons unfamiliar with the operating rules to use it
- do not use lit matches and a lighter when checking for leaks
As for gas cylinders, you should only refuel them at specialised refuelling points. They should be stored in well ventilated areas and not on balconies, in flats or garages. They must be kept upright and in the shade, as they must not be exposed to the heat of sunlight.
Possible problems can also be judged by the colour of the flame in the burners. They should be calm and have a deep blue colour. Red, green and orange colours in the flames should be reported to the gas engineer
The most important rule is not to ignore the regulations for the safe operation of appliances.
The gas appliances installed in your home must be in good working order, comply with all technical requirements and be inspected and serviced at regular intervals. The use of faulty appliances is strictly prohibited.