Assertion: steam engine's piston | /r/CapableOf | return to its previous position
Facets:
Source sentences:
text: When the tube cooled, the piston returned to its previous position.
text: Once the available energy has been removed, the remaining hot gases are vented (often by opening a valve or exposing the exhaust outlet) and this allows the piston to return to its previous position (top dead center, or TDC).