Assertion: boiler's heat | /r/CapableOf | weaken the crown sheet
Facets:
value: at normal working pressure
type: MANNER
Source sentences:
text: Boiler explosions are of a particular danger in (locomotive-type) fire tube boilers because the top of the firebox (crown sheet) must be covered with some amount of water at all times; or the heat of the fire can weaken the crown sheet or crown stays to the point of failure, even at normal working pressure.