| LPG installations supplied from replaceable cylinders are classed as Gasfitting work. Liquefied petroleum gas (LPG) is the name given to hydrocarbon fuel gases that become liquid is either a moderate increase in pressure or a moderate drop in temperature, or both, occur. Propane and butane are the two most commonly used gases. General LPG, which is currently available, is 60% propane and 40% Butane by mass and NOT by volume. LPG liquefies at gauge pressures of between 600 and 700 KPA.
HOW LONG WILL MY LPG BOTTLES LAST? The following is an indication and designed to educate the public before deciding to switch to LPG gas supply. If you have questions or wish to discuss alternative options please ask for our technical team on 0800 TEAM EUROThe amount of liquid fuel that can be vaporised from a cylinder depends on the temperature, and how much fuel is in the cylinder. The vaporisation rate determines how much heat energy a cylinder can supply. As a rough guide, a 45KG cylinder can supply an average of 53MJ/h. The following formula is a simple and practical way to find how many 45kg cylinders you need. (further down also a simple calculation to determine how many hours they will last) Number of cylinder = total demand (MJ/h) / 53 For example, you are going to use/install the following LPG appliances: |
  |
| APPLIANCE | INPUT MJ/h |
|---|---|
| Cooker | 55 |
| Water Heater | 25 |
| Space Heater | 20 |
| Space Heater | 8 |
| Total Demand | 108 MJ/h |
| Therefore number of cylinders = 108/53 = 2.038. You should therefore install a supply bank of 2 x 45 KG cylinders with a changeover valve and have a reserve bank of two more 45KG cylinders.In the same way, you can calculate how long the cylinders will last before they run out. By using the examples above, you can see that each kilogram of 60/40 LPG evolves 0.467 m3 of gas. You have decided to use 2 x 45KG LPG cylinders. The HV value of 60/40 LPG is 102.7 MJ/m3 and the maximum demand is 108 MJ/h.
Calculate as follows: |
 |
| Gas Stored | = 90 x 0.467 = 42.03 m3 |
| Energy Stored | = 42.03 x 102.7 = 4316.5 MJ |
| Consumption time | = 4316.5 / 108 (demand) = 39.97 hours! |
