Closures for pressure vessels, and associated systems and methods

A sealing system comprising:

• a first flange including:
• an outer surface,
• a lower surface extending from the outer surface in a first direction,
• an inner surface extending from the lower surface in a second direction transverse to the first direction, and
• a fluid port extending from the outer surface to the lower surface;
• a second flange including:
• an outer surface,
• an upper surface extending from the outer surface in the first direction, and
• an inner surface extending from the upper surface in a third direction that is opposite the second direction;
• and
• a sealing member including:
• a first portion having a first side configured to engage with the lower surface of the first flange and a second side configured to engage with the upper surface of the second flange,
• a second portion extending from the first portion in the first direction, and
• a third portion extending from the second portion in the second direction and the third direction.

A sealing member comprising:

• a first portion including:
• a first end,
• a second end opposite the first end, the first portion having a first width defined by the first end and the second end,
• a first side extending from the first end to the second end in a direction, and
• a second side opposite the first side, the second side extending from the first end to the second end in the direction, the first portion having a first thickness defined by the first side and the second side, wherein the first thickness is greater than the first width;
• a second portion including:
• a first side extending from the first side of the first portion in the direction, and
• a second side opposite the first side extending from the second side of the first portion in the direction;
• and
• a third portion extending from the second portion, the third portion including:
• a first end coupled to the second portion,
• a second end opposite the first end, the third portion having a second width defined by the first end of the third portion and the second end of the third portion,
• a first side extending from first end of the third portion to the second end of the third portion in the direction, and
• a second side opposite the first side, the second side extending from the first end of the third portion to the second end of the third portion, the third portion having a second thickness defined by the first side of the third portion and the second side of the third portion, wherein the second thickness is greater than the first thickness.