Refillable tanks can be refilled with propane when it runs out.
They are usually made of thicker metal cylinders to prevent leaks from frequent hauling and regular use.
They are commonly used in home gas stoves and heating systems.
Single-use propane tanks contain just enough propane for a single use, and are discarded afterwards.
They are lighter and less durable than refillable tanks, which makes them more portable.
They are normally used with portable grills for camping and outdoor trips.
Types according to valves
POL valves can be tightened by turning the valve counterclockwise, often using a wrench to seal it tightly enough to prevent leaks.
When not connected to a grill or other device, the opening is usually stopped with a plug to keep the propane from flowing out.
They also have built-in bleeder valves and pressure relief devices, which help monitor the propane content when refilling.
Acme valves feature thin strands known as Acme threads, which allow the valve to be tightened clockwise and without the use of a wrench.
They also have larger grill fittings for easier tightening and loosening.
They usually come with built-in safety controls, which are opened when the tank is connected to a grill.
Overfill prevention device (OPD) valve
OPD valves have three-lobed handwheels, unlike the other valve types which have five or more lobes.
They are required on all tanks with capacities of four to 40 pounds.
They also feature and additional safety control built into the cylinder, which monitors propane content and prevents overfilling.