Powder supply apparatus and AM apparatus using a powder supply apparatus

A powder supply apparatus comprising:

• a container configured to store powder therein;
• a supply passage configured to supply the powder to the container therethrough;
• and
• a valve mechanism configured to open and close the supply passage thereby,
• wherein the valve mechanism includes a valve main body movable between a first position, at which the valve main body closes the supply passage, and a second position, at which the valve main body opens the supply passage, and further includes a valve seat configured in such a manner that the valve main body is seated thereon,
• wherein the valve main body includes a first seal portion and a second seal portion,
• wherein the valve seat includes a first seat portion on which the first seal portion is seated, and a second seat portion on which the second seal portion is seated,
• wherein the valve mechanism defines a space sealingly closed when the first seal portion is seated on the first seat portion and the second seal portion is seated on the second seat portion, the sealingly closed space being defined between the first seat portion and the second seat portion, and
• wherein the valve mechanism includes an exhaust passage configured to exhaust gas from the sealingly closed space therethrough and a pressure monitoring passage configured to be used to monitor a pressure in the sealingly closed space.