Learn about tank level indicators and the functions they perform.
Knowing how to read tank level indicators is key to safely using propane gas tanks. According to the National Propane Gas Association, Americans use 11 billion gallons of propane gas (liquefied petroleum) every year. Used both in the home and at campsites, propane gas is a pressurized fuel source that when ignited provides heat for numerous tasks. Propane is an affordable but combustible fuel, and understanding how tank level indicators work is just one important aspect of safely handling propane.
A tank level indicator is a meter that displays the amount of gas remaining in a fuel tank, that lets the consumer know when to change or refill the tank. This meter comes in a variety of forms, both pre-attached to the tank and as an attachable addition.
Tank level indicators come in two types: underground tanks and propane cylinder tanks. Underground tanks have a 100- to 1,000-gallon capacity and are buried so that only the tank level indicator and other gauges are left sitting above ground. The gauges are enclosed within a metal dome that sticks out of the top of the tank.
Propane cylinder tanks are commonly used in outdoor grills and other recreational appliances and vehicles. Propane cylinder tanks may have a small gauge on the top of the tank indicating the tank's remaining capacity, but in most cases these smaller tanks require the attachment of an indicator.
Some tank level indicators are not located on the actual gas tank. As a result, manufacturers offer a propane tank scale for tanks without attached indicators that allows an individual to determine how much gas is left in a tank by the weight of the tank.
A sensor indicator can also be purchased separately from the propane tank and attached to the outside of the tank to determine the level of the remaining gas. Another type of gas level indicator is for propane-powered grills and comes as a separate unit that attaches to the grill between the tank and the grill regulator. Tank level indicators come in a wide range of formats, but all are meant to indicate the amount of gas remaining in a propane tank at any given time.
The indicator or gauge on a large propane tank follows a standard system of measurement. The percentage displayed on the indicator correlates with the amount of gas remaining in the tank and depends on the capacity of the tank. For instance, if the indicator or gauge on a 150-gallon tank reads 80 percent, there are 120 gallons of gas remaining in the tank. If the indicator on a 500-gallon tank reads 50 percent, then there are 250 gallons of propane still in the tank. Whenever the tank level indicator indicates 25 percent, regardless of tank size, it is time to refill the tank before the gas inconveniently runs out.
On smaller cylinder tanks, the attachable level indicators are usually much easier to read and indicate gas levels using simple colors systems and messages, such as an arrow pointing to low gas or full. The method of indication varies among tanks, and when in doubt on how to read a tank level indicator on a small (four to 40 pound) tank, an individual should refer to the user manual or contact the propane tank supplier.
When a propane tank is overfilled, the possibility of a leak increases. Tank leaks can result in fires, injury and even death. Although considered a safe fuel when used correctly, propane gas is a form of liquid petroleum and is highly flammable and combustible.
According to the National Fire Protection Association, overfilling prevention devices (OPDs) have been installed in all propane tanks manufactured since April 2002. OPDs are located in the valve area of the propane tank and are made to cut off further gas intake after a tank reaches eighty percent of its total storage capacity. This cut-off requirement is placed on all propane tanks that hold between four and 40 pounds of gas. Tanks manufactured before April 2002 are supposed to be fitted with OPDs before they can be refilled, but there is always a chance that these older tanks do not have OPDs. To check that a tank has an OPD, the user should look for either a triangle-shaped wheel on the valve or, in older models, a stamp stating OPD on the valve area.
Millions of dollars of property damage, hundreds of injuries and several deaths occur each year because of the unsafe handling of propane gas and propane tanks.
Safe handling of propane gas and propane tanks includes the following:
Whenever there is a doubt about the safety or reliability of a propane tank, it is best to simply discard the tank.
In most cases, small cylinder propane tanks can be refilled at the place of purchase. The Internet is a great search tool for locating propane suppliers in a given location. For larger underground tanks, refilling is carried out by either the local propane company or the company from which the tank was purchased.
When propane tanks become damaged or empty, they should always be disposed of in accordance with municipal laws. An individual should contact their municipal waste department to determine the usual disposal procedure in their area. The size of the tank may determine the required disposal method. Some municipalities allow for small tanks (a couple of pounds) to be placed in the regular garbage can for collection. Larger tanks may be taken to a hazardous household waste site.