Yes propane tanks do have pressure relief valves to allow the release of excess buildup of pressure in the propane tank.
The pressure relief valve may be separate from the valve itself on larger propane tanks and on smaller propane tanks the pressure relief valve may also be built into the main propane tank valve.
All propane tanks are required by law for safety to have pressure relief valves on them.
So yes all propane takes especially the newer propane tanks have pressure relief valves.
Never operate or install a propane tank without a properly working pressure relief valve installed.
Have the propane tank inspected as well especially if it's a large propane tank.