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Have you ever considered what goes into designing and producing propane storage tanks? From steel to technology, there are many considerations that go into ensuring the longevity and safety of propane storage tanks. There are several misconceptions about propane tanks used in residential applications, which will be de-mystified in this article.
The reality is that propane tanks are designed and manufactured to withstand weather, a wide range of temperatures, and underground burial while maintaining their safety. In fact, propane tanks can have a life of up to 30 years or more when installed and maintained properly. And the propane itself is a non-toxic fuel that dissipates when released and will not contaminate soil or groundwater.
Cleveland, Mississippi-based Quality Steel Corporation has been manufacturing propane tanks since 1957. D.D. Hardy, director of sales, says that a common misconception he hears about the safety of underground propane tanks is that they are bad for the environment and can damage the soil if they leak. “In fact, all manufacturers follow strict ASME industry standards to ensure the tanks will last for many years. These standards include underground tank paint and connection points for anode bags that are buried with the tank to keep it from rusting.”
How Propane Tanks Work
Propane is stored as a liquid to save space and make it easier to transport and store. Propane is naturally a gas at standard temperature and pressure, but it can be easily liquefied by applying pressure. When stored in a tank under pressure, propane becomes a liquid, and when the pressure is lowered in the tank, by an appliance starting for example, it vaporizes back into a gas.
Propane tanks are typically manufactured from high-grade steel with welded seams, are tested throughout production, and meet manufacturing standards required by the American Society of Mechanical Engineers (ASME) for their safety.
Other common components of propane tanks and propane systems are:
- Fill valve: A double back check valve in the container that can be connected to by a fill hose for refilling.
- Relief valve: A safety mechanism designed to vent propane vapor if the tank becomes over-pressurized.
- Service valve: Allows propane vapor to be removed from the tank and connects to the gas piping system.
- Propane regulator: Lowers the pressure of the propane vapor and controls the flow from the tank to the appliance where it is used.
- Gauge system: Helps monitor liquid propane levels and/or the pressure in the tank.
Buried propane tanks, also known as underground tanks, store propane beneath the ground and are designed with specialized features for this purpose, ensuring safety and temperature stability. While the tank is buried, they typically have a small dome above ground for access to a riser that contains the valves and gauges. They work similarly to above-ground tanks, but the earth surrounding the tank provides insulation, protecting it from extreme temperatures and the elements. Underground tanks are protected from corrosion with cathodic protection, a technique that makes the tank the cathode of an electrochemical cell by connecting it to a more easily corroded sacrificial metal to act as the anode. Businesses and homeowners may prefer tanks to be buried to improve the “curb appeal” of the property. “A properly installed and maintained propane tank can be used safely for many years. Always work with your propane marketers to ensure the propane system is inspected by a trained and qualified propane technician on a regular basis,” said Hardy.
Tank and Cathodic Protection Monitoring Improves Underground Propane Tank Safety and Longevity
An underground tank requires cathodic protection, because it is exposed to additional elements such as soil and water. There is a more advanced method of monitoring cathodic protection: cathodic sentinel monitoring. The technology provides continuous monitoring of moisture, current, and voltage levels within underground tanks, delivering real-time reporting that spots problems before they become performance or safety issues. The cathodic monitor is mounted on the underground tank during manufacturing and can be installed on any type or size of propane tank.
Propane bobtail drivers inspect the tank every time they fill it. Their inspection includes a visual check for leaks, corrosion, and damage to the tank, fittings, and valves. The cathodic protection is also required to be tested periodically to ensure that the anode has not deteriorated and is properly protecting the tank from becoming corroded. Over time, the sacrificial anode may need to be replaced. Its longevity depends on the condition of the container coating, the type and resistivity of the soil it is buried in, and the moisture of the soil. This is why periodic testing according to code is important. “Manufacturers have made significant technical improvements so that propane tanks and their components are installed to exacting specifications using calibrated equipment. Tank manufacturers like Quality Steel have SAFETY as their No. 1 core value and always look for ways to ensure it’s at the top of the list,” said Hardy.
Smart Innovations
Remote tank monitoring via sonar sensors
Sonar tank monitoring solutions help manage tank propane levels and usage in real-time and streamline delivery. The sensors can measure within +/-1% of the actual tank level, which exceeds mechanical gauge technology that only has an accuracy of +/-5%. Sensors install easily with their built-in super magnetic mounts or custom adhesive collars. The collected data/telemetry alerts both the consumer and supplier to liquid levels, possible issues, projected runout dates, and energy usage trends. Data is securely stored in the Cloud and connects to a smartphone, tablet, or desktop.
Digital tank monitors
Another high-performance innovation is the digital tank monitor that conducts real-time monitoring of liquid propane fuel levels in a tank, allowing suppliers and homeowners to avoid run-outs and plan for deliveries. It takes a reading every 6 hours and transmits data every 24 hours. Built-in text and email notifications alert when the fuel level drops below a certain threshold, helping eliminate run-outs.
Smart lid
A “smart lid” is a protective and durable propane tank lid with a built-in tank monitor with a battery life of 20+ years. The lid has a protective waterproof polypropylene casing that keeps the monitor out of the way of the valves and connections. The monitor is designed to clip into the lid in a position that ensures a consistent placement for the strongest signal and easy installation. It works on both vertical and horizontal propane tanks, as well as underground tank systems.
Paint color
For above ground tanks, NFPA 58 Anex A.6.8.1.4 says that generally, a light-reflecting color paint is preferred unless the system is installed in an extremely cold climate. Lighter, reflective colors like white, silver, or light gray help prevent overheating and potential over-pressurization of the tank by reflecting sunlight, while darker colors absorb heat, increasing pressure inside the container. Some manufacturers offer a variety of colors that meet code beyond the typical white, including gray, tan, red, and green.
Hardy says: “The quality of the paint and how it’s initially applied by propane tank manufacturers has improved tremendously. It provides much better fade protection from the sun, even in coastal areas where there’s salt spray to deal with. Aboveground tanks are often repainted by propane companies to keep them looking new.”
The 2024 NFPA 58, Liquefied Petroleum Gas Code provides the latest standards for the safe design, construction, installation, and operation of LP-Gas systems, including piping, equipment, venting, and transportation, with updates to cover modern LP-Gas hazards.
Innovative Technologies Enhance Propane Tank Safety and Longevity
When considering propane for your property or projects, rest assured that both above ground and buried propane tanks really are engineered and manufactured with safety and longevity in mind. They can last decades and have built-in safety features to prevent corrosion and over-pressurization. Innovative technologies are regularly developed to further improve how tanks are monitored and protected from the elements.
