Q: What does LPG stand for?
A: Liquid Petroleum Gas
Q: Where does LPG come from?
A: In the process of making petrol from crude oil, one of the by-products is a mixture of petroleum gases. The mixture is made-up of mainly Propane (±45%) and Butane (±55%)
If the mixture contains more Propane than Butane, then the LPG will burn quicker and as a result have a more potent smell due to the increase in exhaust fumes. This could cause the heater to have more of a smell than normal. Also, a wrong mix (or “dirty gas”) can cause the appliance to malfunction (e.g. take long too ignite, or not burn properly).
Q: What is meant by Liquefied Gas?
A: When the Petroleum Gas comes from the refinery, it is put under pressure which causes it to turn to a liquid – it becomes liquefied. The pressure required is about 700 kPa (kilo Pascal’s). Atmospheric pressure is 1 kPa, so in other words it is 700 times more pressurized.
Q: How is LPG stored and transported?
A: In order for the LPG to remain a liquid, it must remain under pressure. Therefore it must be pumped into specially designed container, or vessel that can hold a pressure of about 700 kPa. They are commonly called cylinders. There are various different sizes of cylinders but Alva only does the 3kg, the 5kg and the 9kg.
Q: Does LPG need air to burn?
A: Like all fires air must be present for the flame to burn. LPG needs to mix with the air to form a large volume of flammable mixture. LPG is so economical that one volume of liquid, after becoming 270 volumes of gas could then combine with air to bring the total volume up to as much as 10 000 volumes of useable (flammable) combustible gas.
Q: Can a cylinder be overfilled?
A: Yes. Cylinders should only be filled to 80% of the cylinder capacity. This allows for gas expansion/vaporization into the remaining 20% space.
If the cylinder is filled to the top, and then warmed the liquid expands and the cylinder can burst open. This is very dangerous and could cause serious damage and probable injury. It should therefore be kept away form extreme heat. Over filling also causes issues with a gas product not functioning correctly as liquid is being pumped into regulator blocking it up.
Q: When can the cylinder burst?
A: Cylinders are made of such high safety standards that with normal / proper use, they will not just burst. If the cylinder however is heated up (on a flame or a stove for instance) the cylinder could get red hot and burst open. It will cause a very serious fire and damage to property. A cylinder should never go on a stove, or be left in direct sunlight.
Q: Why does LP Gas smell?
A: In its natural form, LPG is odourless. In order to assist in detecting gas leaks, an additive called Ethyl Mercaptan is added to the mix. This stinks like rotten eggs and the smell will increase as the cylinder empties out.
Q: How do I detect a gas leak?
A: Mix some soap (like sunlight liquid) and water to make a soapy solution. Pressurize the gas appliance by opening the gas valve (whilst it is connected to the gas appliance). Cover all the connections with this soapy solution using a sponge. If there is a leak, bubbles will form.
Q: Is LP Gas toxic?
A: No, but if a sufficient amount is inhaled, you could get sick and even suffocate. That is why it is important to have adequate ventilation at all times.
Q: What different type cylinders are there?
A: There are two types: Domestic and Industrial types. Domestic cylinders include anything up to 7kg’s (3kg, 5kg or 7kg). They work with an L-shape regulator. The industrial cylinders are all cylinders with a capacity of 9kg’s and over. They require a bull-nose regulator for usage.
Q: How long does the gas last if used correctly on an appliance?
A: Any appliance should have a gas consumption rate printed in the instructions or on the product. This is usually measured in grams. You then convert the capacity of your cylinders to grams (e.g. a 3kg cylinder would be 3000 grams) and divide the cylinders’ capacity into the consumption rate. For example if you are using a heater that uses 280 grams of gas per hour with a 3kg cylinder, the calculation is 3000 divided by 280. This gives you just over 10 and a half hours of usage.
Q: What is a flame failure protection device?
A: If the pilot flame dies, the thermocouple system will cool down. The sensor will close the electromagnetic valve cutting the gas flow off. This will stop the gas from flowing through the system, turning the heater off.
Q: What is infrared heating?
A: Infrared heating systems refer to pieces of equipment or appliances that are placed inside the space to provide heating. Heating occurs through radiation heat transfer. Radiation heat transfer is the exchange of thermal energy between two or more bodies.
The ceramic panels create infrared heating, heating objects around the heater as well as the air (convection heating).
Q: What is a positive off switch?
A: In older heaters one could only switch the heater off by closing the valve on the cylinder. A positive off switch enables the user to switch the appliance off without having to close the valve on the cylinder (like a stove or BBQ).
Q: What is an ODS (Oxygen Depletion Sensor)?
A: A safety device that activates the heaters’ monitoring device in case excessive levels of CO² (carbon monoxide), are detected. Continuous burning reduces the levels of oxygen, causing the pilot flame to become unstable and lift off the thermocouple (flame failure protection device) tip. The appliance then turns off automatically long before the situation becomes dangerous.
Q: What effects does separate burner chambers have on a heater?
A: On older heater models all three ceramic panels were mounted on a single burner chamber. This allowed gas to “drift” to non-burning panels and escape through it, allowing a slight increase in the gas smell and the wasting of fuel. The new generation of heaters has 3 independent gas chambers. This prevents the gas from floating to unused panels and thus reduces gas emission odours.
Q: How long is the heater supposed to burn for?
A: In your instruction manual or on the sticker in the back of your heater it will tell you the g/h (grams per hour). Take the amount of grams from gas cylinder e.g. (3kg = 3000g / 4.5kg = 4500g etc) and divide it by the g/h of your appliance. The total you get will be the maximum amount of hours the appliance will be able to burn for.
Q: How can I see if the cylinder was over filled?
A: The cylinder neck contains information on the weight of the cylinder. The tare weight (TW) is the weight of an empty cylinder. Add the tare weight to the capacity of the cylinder (e.g. TW – 5.6 and capacity 4.5 = 10.1kg) and weigh it. If it exceeds the total weight, then your unit is over-filled. In such an instant, the cylinder must be returned to the re-filling station. Users are no longer allowed to purge the excess gas themselves.
STAINLESS STEEL BBQ FAQ’s
Q: What is the difference between stainless steel and normal steel?
A: Stainless Steel contains more Chromium than ordinary steel. Steel rusts when exposed to air and moisture. The iron oxide film (rust) is active and it accelerates corrosion by forming more iron oxides. Stainless Steel contains sufficient Chromium to form a protective film, which prevents further surface corrosion and blocks corrosion from spreading into the metals internal structure.
Q: Can Stainless Steel rust?
A: The answer is yes. Under the right circumstances it can. What makes stainless steel "stainless" is a chromium oxide passive layer. If this layer is damaged, be it as a result of the manufacturing process or some other means, the exposed metal is able to be attacked and your stainless steel will show signs of rust. The trick is to restore the passive layer as soon after manufacturing as possible, as well as limit the exposure of the material to iron contamination through the manufacturing cycle. Different grades of stainless steel will rust quicker than others.
Q: What grade Stainless Steel are the Barbecues and why this grade?
A: All the Barbecues are graded 430 Stainless Steel. This grade is easy to manufacture products with and is more cost efficient.
Q: Is Stainless Steel magnetic?
A: The 200 and 300 range of Stainless Steel is not magnetic, but the 400 range is magnetic, due to less or no nickel.
Q: How do I clean my Stainless Steel unit?
A: It is important to always keep your appliance clean. Always use the mildest cleaning procedure first, scrubbing in the direction of the grain. It is recommended to use water and a mild detergent after every use. For further protection, oil the unit once every 2-3 months in the following way:
Use some baby oil and some kitchen paper and drop a couple of drops of the oil onto a clean cloth, then rub it around and all over the item thoroughly. Then take a clean sheet of kitchen roll and rub down and polish the whole appliance evenly to remove all streaks. The baby oil dilutes and liquefies the stains and marks leaving a lovely, blemish free finish.